texts: Can a Miner or Mining pool have exclusive access to a transaction and its fees?

texts:
Edit: This is a dumb question.  I was new to Bitcoin when I asked it.  Feel free to ignore or delete this Q:

Is it possible for a miner or mining pool to receive and not retransmit to peers information about a pending transaction?

Here is the scenario:

Several "normal" transactions are transmitted P2P with a transaction fee ranging from zero to 0.20 BTC.  One client wants to have priority processing with a miner either because they have a special business agreement, are a frequent user, or pays a fee.

Likewise the miner wants to have "first dibs" on high value transactions + fees, sometimes at the exclusion of other miners who aren't part of that "fee collective".

Question:

Is it possible for a miner to get "first dibs" access to a transaction, before the rest of the network sees the pending transaction?  How would this work, and can the current codebase support this?


texts: what is the mathematical problem in each block which is difficult to solve?

texts: in blocks page it says each block has a solution to solve difficult mathematical puzzle, what is that difficult mathematical puzzle?


texts: Vouching for (or against) the reputation of a bitcoin user

texts:
Since it's possible to link non obfuscated transactions to a "user" does is make sense, or it is possible for anonymized users with an established transaction history to "vouch" for another?

I'm thinking this would be similar to EBay's seller rating system, where people can prove they did a transaction with someone and then comment on the experience accordingly.


texts: Broadcast a transaction, issue with Context missing from thread created by BitcoinJ

texts:
In this code i receive an already signed transaction in the form of a byte array and i would like to broadcast it to the Bitcoin network.

override fun onHandleIntent(intent: Intent?) {
    org.bitcoinj.core.Context.propagate(Constants.CONTEXT)
    if (intent != null) {
        when (intent.action) {
            ACTION_BROADCAST_TRANSACTION -> {
                initializeBlockchain(null, 0)
                val transactionByteArray = intent.getByteArrayExtra("TX")
                val tx = Transaction(Constants.NETWORK_PARAMETERS, transactionByteArray)
                tx.getConfidence().setSource(TransactionConfidence.Source.SELF);
                tx.setPurpose(Transaction.Purpose.USER_PAYMENT);
                SpvModuleApplication.getWallet()!!.maybeCommitTx(tx)
                if (peerGroup != null) {
                    val transactionBroadcast: TransactionBroadcast = peerGroup!!.broadcastTransaction(tx)
                    val future : ListenableFuture<Transaction> = transactionBroadcast.future()

                    future.get()
  ..........

Issue is that in my own code i already propagated the context but then internally in BitcoinJ it creates another thread when it has enough peers, and then broadcast the transaction from this thread, which fails as the Context is not propagated there.

Any pointers as to what i am doing wrong ?

Thanks.

  09-14 15:14:52.867 8281-8330/com.m.s.test E/ExecutionList: RuntimeException while executing runnable org.bitcoinj.core.TransactionBroadcast$EnoughAvailablePeers@838ec24 with executor org.bitcoinj.utils.Threading$2@7b38d
                                                                            java.lang.IllegalStateException: missing context at org.bitcoinj.core.Context.get(Context.java:110)
  at org.bitcoinj.core.Transaction.getConfidence(Transaction.java:1198)
  at org.bitcoinj.core.TransactionBroadcast$EnoughAvailablePeers.run(TransactionBroadcast.java:134)
  at org.bitcoinj.utils.Threading$2.execute(Threading.java:141)
  at com.google.common.util.concurrent.ExecutionList.executeListener(ExecutionList.java:156)
  at com.google.common.util.concurrent.ExecutionList.execute(ExecutionList.java:145)
  at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:185)
  at com.google.common.util.concurrent.SettableFuture.set(SettableFuture.java:53)
  at org.bitcoinj.core.PeerGroup$14.onPeerConnected(PeerGroup.java:1938)
  at org.bitcoinj.core.PeerGroup$11.run(PeerGroup.java:1565)
  at org.bitcoinj.utils.Threading$UserThread.run(Threading.java:107)


texts: Is disclosing an index used for generating BIP32 addresses insecure?

texts:
I'm writing an e-commerce system that uses BIP32 to generate addresses. I was thinking of using the order number (which is shown to the user) to as the index for generating the address to pay to.

Would doing this help someone trying to steal my money, or help someone trying to link my addresses together?


texts: How can I import wallet.dat file to Bitcoin ABC wallet without downloading whole blockchain?

texts: I keep my BTC in Bitcoin Core wallet. I would like to start using my BCC but full node is downloading whole blockchain. How can I avoid it?


texts: How does a non-segwit full-node validate a SegWit input

texts:
From segwit part of reading bitcoinbook, there is an example for upgrading P2PKH to P2WPKH:

  Alice created a transaction to pay Bob for a cup of coffee. That
  transaction created a P2PKH output with a value of 0.015 BTC that was
  spendable by Bob. The output’s script looks like this:
  Example P2PKH output script

DUP HASH160 ab68025513c3dbd2f7b92a94e0581f5d50f654e7 EQUALVERIFY CHECKSIG

  With Segregated Witness, Alice would create a
  Pay-to-Witness-Public-Key-Hash (P2WPKH) script, which looks like this:
  Example P2WPKH output script

0 ab68025513c3dbd2f7b92a94e0581f5d50f654e7

Inputs for them are like below:
For traditional P2PKH:

[...]
“Vin” : [
"txid": "0627052b6f28912f2703066a912ea577f2ce4da4caa5a5fbd8a57286c345c2f2",
"vout": 0,
         "scriptSig": “<Bob’s scriptSig>”,
]
[...]

For P2WPKH:

[...]
“Vin” : [
"txid": "0627052b6f28912f2703066a912ea577f2ce4da4caa5a5fbd8a57286c345c2f2",
"vout": 0,
         "scriptSig": “”,
]
[...]
“witness”: “<Bob’s witness data>”
[...]

So what if a full-node has not upgraded to new version with support to segwit? It seems that client without support for segwit will always validate the second input as true. Because in the book, it is said:

  As you can see, a Segregated Witness output’s locking script is much
  simpler than a traditional output. It consists of two values that are
  pushed on to the script evaluation stack. To an old (nonsegwit-aware)
  bitcoin client, the two pushes would look like an output that anyone
  can spend and does not require a signature (or rather, can be spent
  with an empty signature).

Question 1:
0 and ab68025513c3dbd2f7b92a94e0581f5d50f654e7 in stack-based bitcoin script does not return true.
Why the the "two pushes in segwit output looks like anyone can spend and does not require a signature" to old client?

Question 2:
What is the <Bob's witness data>? It looks like that <Bob's witness data> is different from <Bob's scriptSig>. Can anyone provides an example?


texts: Programming a solution to know when a Bitcoin Address has stored a target amount

texts:
Sorry, I'm probably not going to use the correct terms here.

Does anyone know of, or how to use bitcoind (or of an external library) that can look at or even provide event driven mechanisms to monitor when an address has received equal to or more than a target amount.

I know of the websocket API available from blockchain but I'd ideally do it in house using my own systems if possible.


texts: What is the oldest physical bitcoin artifact?

texts:
The bitcoin network has been running since early 2009, but what is the oldest physical artifact related to bitcoin?

I don't mean computer hardware that was used to run bitcoin, unless it is designed specifically for bitcoin use (ASICs, hardware wallets, etc).

I think paper wallets are an obvious answer as one of the oldest physical artifacts, but those are something best kept private. So more interestingly, what is the oldest 'public' sort of artifact? Material from an early conference? Casascius coins? Something else?


texts: Where can I learn more about BIP30; namely the exploit and the background discussion?

texts:
I'm having trouble understanding the bug that was fixed in BIP030, and how it would be exploited.

Is the premise of this attack that there would have to be a netsplit and the chain was forked, then subsequently rolled back the old transactions?

What would the validation psuedo-logic of the following look like?

  There are several potential solutions to this problem:

  Guarantee that all coinbases are unique, making duplicate transactions very hard to create.
  Remember previous remaining outputs of a given transaction identifier, in case a new transaction with the same identifier is
  added.
  Only allow duplicate transactions in case the previous instance of the transaction had no spendable outputs left. Removing a block from
  the chain can then safely reset the removed transaction's outputs to
  nothing.

The reason I'm asking is so I can develop additional validation rules that work in parallel with the existing client.


texts: Why does getheaders P2P API return more than getblocks?

texts:
I've been reading through the Bitcoin P2P protocol documentation as well as experimenting with Bitcore library but confused about one thing.

So getblocks seems to return inventory objects, which are just pointers, so you have to make another getdata request using those inventories to get the actual block.

And getheaders seems to return headers from starts to stop.

They act similar, except that getheaders returns more than just the pointers. I'm confused here because I feel like getheaders should be the "light mode" which only downloads small amount of data compared to getblocks. This is also shown by the fact that getheaders download up to 2000 headers by default while getblocks downloads up to only 500 inventories.

So am i misunderstanding any of this? Why does getheaders return more information than getblocks AND also return more results that getblocks (2000 vs 500)?


texts: Can I create my own 24 word system using JavaScript or Ruby?

texts:
Ledger Nano X has a 24 word system.  So can I create this system on my own computer?
And I can use 3 words, 9 words, 24 words, just by a method like the following?

Say, for simplicity, if it is 3 words, "apple", "pisces", "steve"
Now I sort them, in alphabetically order, but no need to, because they already are sorted
Now use any package to create a Private Key A and Public Key A from them
Now, for the so valuable BitcoinPrivateKey of my "address" that has the bitcoin, use the public key in step 3 to encrypt it.
Now I can email this code to 20 of my friends or post it in my Google Docs or any website
So only the private key A can get back my valuable BitcoinPrivateKey, because that token I emailed to 20 friends, if I use the private key A to encrypt it (to pass through the private key function), then I will get back BitcoinPrivateKey. (that's the property of private key and public key, if f is a function of private key and g is the function of public key, then we know x = f(g(x)) and x = g(f(x)) meaning pass through f and then g, and you get back itself. Likewise for passing through g and then f, you get back itself.
So from now on, I only need to remember "apple", "pisces", "steve", and I can generate Private Key A and Public Key A again. And then I can ask any of my friend what that token is, and use Private Key A to get back your BitcoinPrivateKey, and therefore get back my bitcoin and sell it.

Does it work?  Is there any online system that can do that? But that will mean we need to enter the private key on a webpage and let it go through the Internet once, with HTTPS it is better, but if that online system has some loophole, then the private key could have leaked.


texts: Is there an altcoin that is only feasible to mine by CPU?

texts:
I'm interested in mining altcoins, mainly to turn some servers into (literal) space heaters, since it's winter. One thing that really interests me is if an altcoin has been designed to only be mineable by traditional CPUs. The big thing I can think of to cause this is large memory requirements. A large memory requirement for hash processing would cause current GPUs to be slower than CPUs (due to the individual "cores" of the GPU not having enough direct memory). It would also cause ASICs and FPGAs to be very difficult to develop to be faster than CPUs, and expensive. This is because you effectively reduce the mining complexity so that it bottlenecks at the memory bus (which is much harder to significantly speed up)

I'm sure I'm not the only one to have thought of such a scheme. Is there an altcoin out there that is designed with this kind of ideal behind mining?


texts: Does a trusted blockchain import from BitcoinCore require that chainstate and blocks be from the same source?

texts:
Can the chainstate folder from a pruned node be used with the blocks folder from a full node to provide the full blockchain?  Assume that both nodes have been running for months.
If the blocks folder contains references to filenames in the chainstate folder, then the answer is no.  I know this because the filenames in chainstate on the full node are different from those on the pruned node.
If, on the other hand, the chainstate folder stands as a self-contained and full record of the UTXO Set including all pointers, filenames, and identifiers required to interpret it, then it seems that I will NOT need to import chainstate from the full node to the cloud server.
Bonus question! Out of curiosity, there's another question here that doesn't affect my situation, but it would be nice to understand why the answer is no if it's no.  If the chainstate folder on a full node got corrupted, could the chainstate folder from a pruned node be dropped in to recover?
Clarification
Both the blocks and chainstate folders reflect a block tip, and if the two folders reflect different block tips, they will be incompatible.  I should have made it explicit that the question assumes that the two different sources of folders would both be synced up to the same block height.
An interesting edge case is what happens if they are using the same block height, but the blocks they used at that height are two valid but different blocks.


texts: "request coins" address is different to top right qr code

texts:
Bitcoin wallet app (android app).

I'm familiar with how an Hierarchical Deterministic wallet generates addresses, but I'm confused by the ever changing address of "receive coins" button in the bottom left.

Literally every time I click I'm given a different address, but the qr code in top right is always the same (and informs me it will update to new address after a transaction), but the bottom left doesn't show the actual address, only qr code, and I like to save the address each time it changes so I know which wallet it's from (so later I can confirm which of my multiple wallets will receive the payment) and also go back and check I've copied it correctly etc etc.

What's going on with "receive coins" option?


texts:
Assuming that SHA-256 is not save anymore. How could the Bitcoin blockchain get attacked? Ok I could get the input value for the hash function but could I now easily add my own blocks to the chain? I'm currently confused why there are theses hashes used...

How long would it take to attack the hash now, with a working SHA-256. Could you provide me a calculation with GFLOPS or something?

best regards


texts: How does the bitcoin exactly prevent Double spending attacks?

texts:
I recently started reading about Bitcoin, the idea seems hard to get, and I'm trying to understand the basics now.

I read the white paper by Satoshi Nakamoto but I still have some confusions

First, it has been said that the main advantage of the Bitcoin is its capability to prevent the Double spending attacks, my questions are:

Is this because of the idea of blockchain or the proof of work?
Can anyone spend his bitcoins twice in two different transactions and
two different blockchain? if not, how does the protocol prevent
prevent such a case?
What exactly the process that minors follow to detect that a
certain transaction is spending the bitcoins twice?
Why don't minors (voters) simply accept a new block without even
check if it's truly valid or not? what are the consequences?

I'm sorry if my questions seem very basic,

Thanks in advance


texts: Is there any way to mathematically optimise Bitcoin transfer fee?

texts: Say you want to transfer X amount of Bitcoins between wallets and Y amount of transaction fee will be levied. Now you have option to send extra Bitcoins for the same amount of transaction fee, so how can you calculate what is the maximum amount of Bitcoins that can be transferred for that Y amount of transaction fee?


texts: How to restore a ripple wallet, having the security key?

texts:
If I try to login to ripple.com I get this message

Fetching wallet...
Payward  Wallet not found (Username / Password is wrong)
Local browser  Wallet not found (Username / Password is wrong)

It might be a bug, but let's assume I actually somehow corrupted my password.

Luckily I still have my security key, but I've no idea on how should I use it to restore my wallet.


texts: What happens to the transaction using the coinbase transaction output of a block later considered stale?

texts:
As I understand it, a stale (orphan?) block is determined after it is out competed by its sister block. But I can't help but wonder what would happen to the coinbase transaction's output of the stale block.

Although stale block usually is shorter than 4 blocks. It is certainly possible that some transaction might have used the coinbase of a later staled block. Given scenarios when receiver might not be able to wait for 6 blocks of confirmation, it is possible that some recipient might end up having his transaction output invalidated.

For this kind of case, is there a common practice exist to prevent the loss of the recipient (other than 6 blocks of confirmation)? Or is this scenario considered rare enough to be neglected altogether?


texts: When will there be no 'mineable' bitcoins left?

texts: At today's rate of progression when will the market cap of 21 million be reached? If bitcoin increases at such a rate. In addition to this, is it true that when the market cap is reached, miners will still get transaction fees? If so, how much will these transaction fees be?


texts: How to protect a crypto currency from Seed failure

texts:
I have created a new currency based on Forknote/Cryptnote.

It has a small number of Seed Nodes.

I am investigating how to mitigate the risks of currency failure due to Seed Node collapse from

Legislation forcing hosting providers to no longer allow Seed Nodes
A synchronized server attack.

Is the only way to mitigate this to have multiple Seed Nodes in multiple locations by multiple providers? Or is there any way I can rely on continuing to have a small number of Seed Nodes but rely on the distributed nature of local copies on the blockchain on mining machines?


texts: Unable to transfer bitcoin from Multibit - need Satoshi

texts:
When I am trying to transfer ALL my bitcoins from MultiBit wallet - It's giving error saying:

"The send transaction could not be created

The error was "Insufficient money, missing 49967 satoshis"

I am trying to send my bitcoins and I am entering the exact number of bitcoins which it is showing in my wallet for doing transaction. Can someone please help.


texts: Is the threat of computer malware to steal Bitcoin exaggerated?

texts:
Some months ago I put a small amount of Bitcoin into an account and wrote the address and private key into a text file. I have left on my computers and on those of a couple of friends. The money hasn’t been taken.

Where does the main danger come from? Screenshots, key-logging or what?

My main motive in asking this is that I use bitaddress.org offline to generate addresses, but without using Ubuntu or taking out my hard drive. I never copy my private key onto the clipboard, and I wonder whether the danger I face of having my coins taken - particularly if I store more in this way - is real or merely highly improbable?


texts: Why do I get `bitcoind: command not found` in Ubuntu?

texts:
I have built the bitcoin source on my Ubuntu desktop, and have installed the proper libraries via apt-get and building some.

When I do:

cd src
bitcoind -daemon

I get the error:

bitcoind: command not found

and when I do ./bitcoin I get:

bash: ./bitcoin: No such file or directory

What am I doing wrong?


texts: I have read that numerous high frequency trading firms build datacenters near equity exchanges to minimize the milliseconds necessary to get quotes and execute trades. In the case of buying and selling Bitcoin, is my broker's proximity to an exchange relevant? Have we seen Bitcoin brokers start to advertise trade execution guarantees?


texts: Sequence of events that can cause lost money in MultiBit

texts:
If you create a new address in MultiBit, then transferred money to the new address before the wallet was backed up, then your hard drive crashed, will you lose the money?

The first Bitcoin client had 100 addresses, hidden. You could send to a new address and it was most likely already backed up. Does MultiBit do that?


texts:
I have recently heard of a bitcoin theft where the thief used a bitcoin tumbling service in an (apparently unsuccessful) attempt to cover their tracks. From this event I have several related questions:

How does a bitcoin tumbler "launder" bitcoins?
Is a tumbling a viable laundering scheme?
How would tumbling be made a more/less successful?


texts:
I want to pay for something using bitcoin, using Bitcoin-Qt, and the seller has asked:

  Please use the order number as the note/message to receiver info.

Where do I add this info? Presumably they can't see the 'label', so where do I put this note/message?


texts: How can one blockchain with the same block heigth as another, have more Proof-of-Work

texts:
I am reading Andreas M. Antonopoulos's book and In chapter 10 - Assembling and Selecting Chains of Block he writes:

  Under most circumstances this is also the chain [main chain] with the most block
  in it, unless there are two equal-length chains and one has more
  Proof-of-Work.

Can somebody explain how this is possible? How can 2 chains with the same length have different cummulative Proof-of-Work? Is it because they might include block that were mined with different difficulty targets? Not sure how this could happen, but this is my only hypothesis.


texts: Blockchain API support - receive payment IPN

texts:
I'm having some real trouble setting up the Blockchain API on my server

First off is it possible to test it offline with local host?

Secondly, how do I set it up so when a tx is made through my site, it runs a php function to update a database with certain values

Has anyone successfully set up the API before and if so could they please walk me through how I would do it

Thanks


texts: Why are there no Bitcoin price/trade records before 2013?

texts:
Example: http://www.livebitcoincharts.com/
On that chart, it starts at $135. That's quite a sum to start with. Why does it only start in 2013 when it started "blowing up" for the first time?
"All time" apparently means "since sometime 2013".


texts: I'm trying to understand how does bitcore-node, the javascript implementation of Bitcoin protocol, get its data? Can it connect to Bitcoin Core, the original C++ implementation of the Bitcoin protocol, or does it have to connect to other bitcore-nodes ?


texts:
I use GUIMiner to mine bitcoins using my graphics card, and in a pool.
I've upgraded to Windows 8 this morning, but now GUIMiner won't launch!

All I get is the icon in the taskbar for a few seconds, and it disapears. I have no error message, no windows, and no error logs.

I have tried launching the application as an administrator, and in "Windows XP" and "Windows 7" compatibility modes.

How can I fix this problem?


texts: How do I develop mobile applications for Bitcoin?

texts: I would like to develop a mobile Bitcoin application for the Android and iPhone platforms.  What libraries and resources can I use?


texts: How often does a block have only one transaction?

texts:
I was looking at blocks on blockchain.info, and came across this one with only one transaction in it: (the mining reward one)

https://blockchain.info/block-index/512049/00000000000000000429a0c4fbe735b2d8b493daedf0207728543f748c262437

Is that at all suspicious? Does it mean someone was trying to block some transactions from going through? How common are single-transaction blocks?


texts: Can I remove the initial bitcoin folder after installing its binaries to /usr/local/bin?

texts:
I know this's kinda a noob question, but I really want to be sure I'm not making a mistake.
I want to install Bitcoin Core GUI on my Linux by the following steps:

Download bitcoin-0.20.1-x86_64-linux-gnu.tar.gz into the Downloads folder
Extract it tar xzf bitcoin-0.20.1-x86_64-linux-gnu.tar.gz
Copy binaries into the /usr/local/bin: sudo install -m 0755 -o root -g root -t /usr/local/bin ~/Downloads/bitcoin-0.20.1/bin/*

Each step is exact the same as described here: https://bitcoin.org/en/full-node#linux-instructions
The question is: Can I now remove the extracted ~/Downloads/bitcoin-0.20.1 folder after installing the contents of its bin subdirectory into the /usr/local/bin?
Is it enough to have only binaries into the /usr/local/bin to run the program?


texts: why is the number of confirmations rising yet i haven't been credited with the bitcoins?

texts: I have been waiting to receive bitcoins for close to 7 hours now. The number of confirmations is currently 111, so why is it so? here is the transaction batch 95d5dcb612446d67e38ef9246fdcd20a5f500766431321ba9ff7280567d01e59


texts: PHP How can I validate / verify a wallet public key?

texts:
Can someone please help me find some PHP open source on how to validate / verify a bitcoin wallet public key ? I am currently working on a project  and I am implementing multisig, and it seems I can't find any type of information on how to verify / validate a wallet public key.

Example of public key that I am trying to validate: xpub661MyMwAqRbcEwAAmd9DpSfoDEUar3C2e8LtpeMCaaPWMoLjAf3jY3RucUmtim729c2qzGmYPaBcFdkEUQuwgrFjTKFwEKSCfRfd949k4DC

Basically, I want to make sure the user can't add a wrong or invalid key, otherwise the multisig wallet cannot be created when the system will try to create it, and I need to prevent that

Thank you for your time!


texts: Bitcoin Cash accidentally sent to Bitcoin address. Can I get them back?

texts:
I managed my Bitcoins Cash in a Electrum Cash wallet on my PC.
From there, I accidentally sent them to another internet based wallet, but didn't notice that this wallet is for Bitcoin and not Bitcoin Cash.
In the Bitcoin Cash blockchain I can see that the transaction actually took place and that the adress now owns the Bitcoin Cash. The problem is, that this address is a Bitcoin Cash address, and I cannot get access to it.

Is there a way to reclaim this Bitcoin Cash address? I own the address on Bitcoin, but not on Bitcoin Cash.


texts: Not Getting shares but have decent Hashrate

texts:
Just signed up and need help.kinda new to bit mining and am using slushes pool with guiminer and cannot get any accepted shares from my Radeon HD 6870  ,it has Hash rate of 200mh/s and 0 shares after it has ran for a day. I am also mining with my cpu and it is getting around 5mh/s and has gotten over 73 shares,Any help figuring this out would be highly appreciated.

specs:
Amd driver Catalyst Version 15.7.1
Windows 7 64 bit
Cpu Amd Phenom x6 1045T


texts:
I am trying to implement JavaScript interpreter for Bitcoin scripts, but I have problem with counting value of OP_HASH160. I found that

Hash160(x) = RIPEMD160(SHA256(x))

However, when I try to count it this way using CryptoJS library, I get different value than on page http://paulkernfeld.com/bse/.

CryptoJS.RIPEMD160(CryptoJS.SHA256("02c34538fc933799d972f55752d318c0328ca2bacccd5c7482119ea9da2df70a2f")).toString() = "e81794c3da1564a196665dd0f74483185f524fe2"

where "02c34538fc933799d972f55752d318c0328ca2bacccd5c7482119ea9da2df70a2f" is the first element on the top of the stack.

Could somebody explain how exactly operation OP_HASH160 works?

Thx! :)


texts: Bitcoind server strategy. How much disk space?

texts:
I need to host a Bitcoind on a VPS.

My main issue is the disk space strategy. I don't know the amount of MB the blockchain adds per day or per month.

On my disk I have 26GB of disk spent for the Bitcoin installation. There are some numbers about ho much the blockchain will add in disk space over time?

I'm also looking for VPS with a lot of disk space on the cheap. If you have some advise on this, I will appreciate.

Best Regards,


texts:
I have a computer with a Phenom II X6 1090T 3.2 GHz, and a GT430 gfx card. Obviously I know I won't be able to mine lots of bitcoins, but I want to start getting some money for a car and such. Is the only solution to mining by getting a ASIC Machine, or people on other forums run a pool using a huge botnet.

If you guys can give me any tips to start, it would be appreciated.


texts: Why do pools get so often DDoS attacked?

texts:
In other words: who has incentives for attacking pools?

Do you think it's the government?


texts: Is there a way to interact with Bitcoin-qt from Windows cmd and run commands like if I'm running them from Bitcoin-qt console?


texts: get utx scriptPubKey to become an object

texts:
I'm using this python script https://github.com/sebicas/bitcoin-sniffer

When I see a utx I look at each output and find the scriptPubKey

I expected to see something like

"scriptPubKey": {
   "asm": "OP_DUP OP_HASH160 2544bedede7298fe7cedb3fcd0eb5fa73729eb64 OP_EQUALVERIFY OP_CHECKSIG",
   "hex": "76a9142544bedede7298fe7cedb3fcd0eb5fa73729eb6488ac",
   "reqSigs": 1,
   "type": "pubkeyhash",
   "addresses": [
                    "14Q4MdFGqFbP9WPzz3AXjsdxZC68rCQjj1"
                    ]
                }

but instead I see

"scriptPubKey":v��_/{�/k>//��7`HH��

Is it binary or encoded or encrypted??

How do I get the information I need from the utx?

I am looking to get asm and hex


texts:
I sent bitcoins to an offline (air gapped) electrum wallet.  I have blockchain.info proof the transaction took place and verification of the balance in the wallet (i used a watch only address to view balance and transaction history of offline wallet)  BUT electrum online wallet synchronizes but does not show updated balance information.  Electrum can find the funding transaction from the blockchain by the transaction id (Tools->Load transactions-From the blockchain)

Electrum 1.9.8
debian jessie (kali 2 sana)
via socks5 thru tor

resources consulted - none have a working fix

1.
Why I am not seeing received money in my electrum?
wallet.clear_history() does not solve the problem for me

2.
https://github.com/spesmilo/electrum/issues/1525

3.
https://bitcointalk.org/index.php?topic=1221590.msg12943509#msg12943509


texts: Why can’t the genesis block coinbase be spent?

texts:
According to the bitcoin wiki:

  The first 50BTC block reward went to address 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa, though this reward can't be spent due to a quirk in the way that the genesis block is expressed in the code (this may have been intentional).

But where is this quirk? How would you change it to allow it to be spent?


texts: For Application Development is bitcoind RPC the Only Way?

texts:
I am looking at building an application using Bitcoins, and being a newbie the only real resources I have found regarding how to interact with the network is to issue RPC commands to the bitcoin-qt client running as a service.

I've played with this a bit and I am curious if there are other clients that do the same thing? Or is this client the only game in town?


texts: what is the best mining intenisty to use for certain grahpichs cards?

texts: I use cgminer and I have a zotac nvidia geforce gtx 680 graphics card, what is the best intensity to use.


texts: Is there a correlation between Technical Analysis predictions and actual prices?

texts:
Technical Analysis is a disputed method for "predicting" future prices. This blog has been offering technical analysis on Bitcoin for quite some time (AFAIK it's the only one).

Has there been any significant correlation between its predictions (Short/Mid term UP/DOWN) to actual price movements?


texts: Mac OS 10.7.5 compatible with Bitcoin-Qt.app?

texts:
Program runs but doesn't seem to be able to synchronize with network.  Is there more to installing program than just dragging into applications folder?

I'm also confused about why I don't have a Bitcoin folder in Application Support folder of Library folder...  (If invisible, how do I make it visible?)

I'm a returning user after being away for about a year....  trying to access an old wallet.dat file saved on USB stick


texts: what is the meaning of Segwit receiving address and segwit change address ..?

texts:
What is the meaning of different type used in bitgo api like bellow :
Url : https://bitgo.github.io/bitgo-docs/?javascript#add-wallet

m/0/0/0/0 (which is also the ID used to refer to a wallet in BitGo’s system)
m/0/0/1/0 (The first change address of a wallet)
m/0/0/10/0 (first SegWit receiving address of a wallet)
m/0/0/11/0 (the first SegWit change address of a wallet)

what is the meaning SegWit receiving address or SegWit change address..?


texts: How to sync litecoin blockchain (+ bootstrap) from the terminal?

texts:
I've installed Litecoin from the main page, so now I have few executable files, like litecoin-cli, litecoind, litecion-qt, ...

I know, that the easiest way to sync blockchain is to run ./litecoin-qt and it will start the syncing automaticly. More than that, I've downloaded bootstrap.dat, so know the stuff will get synced much faster.

But how can I do it, without QT GUI, only using the terminal?


texts: Troubleshooting "access is denied" error when running cgminer

texts:
I am trying to run cgminer on Windows 7.  However every time I execute the command:

cgminer --scrypt -o http://coinotron.com:3334 -u username -p pass  --thread-concurrency 8192 -I 10 -g 1 -w 256

It says access is denied.

What am I doing wrong?


texts: Why use the master key to encrypt private key? And why just store unencrypted master key in memory?

texts:
When encrypt wallet, using a master key to encrypt private key.The master key is encrypted by the key derived based the wallet's passphrase.
When unlock wallet, the unencrypted master key is stored in memory, but not private keys.

1、Why not directly use the key derived based the wallet's passphrase?
2、Why the unencrypted master key is stored in memory, why not private keys?


texts: What is the difference between Bitcoin Core and UASF?

texts:
I am a little confused about what the actual difference is between Bitcoin Core and UASF, are they both only for SegWit?

If so who is then for SegWit2X?


texts: What is a worker exactly from Antminer Pool Worker field

texts:
So I see on the What is a worker? post that a worker is "simply an identifier for you to use so that you can track different machines within your account".

For someone that just started maintaining bitcoin systems for others and only configures the Antiminers I wanted to get some clarification that may help me understand better.

Note: I have not ever registered for a wallet account (e.g. Antminer, etc.) and only maintain a farm for someone else and was given the detail to plug in per each miner.

Question

Correlated sub questions for context to help understand what I'm trying to get my head around here

Is a Worker any random name you make up right then in the Antminer General Settings > Pool # > Worker field, or do you set these up with your associated Antminer account and then once on the pool start dropping in the names you registered on your account?

I assume once you use one specific Worker name that you will get an error if you try to use that same name on that same pool from another miner device?
The pool is a URL with a port number and the Worker seems to be a private name you use on your account connected to this public URL pool but the Workers in this context are like the private bitcoin miner nodes—if someone else on that same URL pool from another account uses the same Worker name as another account's Worker name, then that does not make any difference—only no duplicates on same account only, right?


texts: How cryptocoin trade engine works?  I want to build a simple trade engine(trading bot) in ruby on rails for cryptocoins. Can anybody lead me through proper steps. I am a newbie to cryptocoins.


texts: How do offchain transactions get validated/confirmed whilst using Lightning network?

texts: How do offchain transactions get validated whilst using Lightning network?


texts: I'd like to buy a mining rig, something like 4 5850 cards, preferably more.  I'd rather not build it myself.  Are there any vendors who sell such machines at a reasonable price?


texts: Does Bitcoin Cash validate the fears about larger block sizes?

texts:
I read on this forum that a larger block size wouldn't necessarily mean less blocks since blocks are mined every ten minutes, and this is why block size should remain smaller --
Wouldn't a full node use nearly the same space for large or small block sizes? .  The argument was that larger blocks lead to less decentralization, which is bad for some reason.  So now Bitcoin Cash is out with its larger block sizes.  So have all the fears of larger block sizes come to bass with Bitcoin Cash?


texts: attempting to decipher a cgminer share.log

texts:
Here is 1 entry from a share processed in a feathercoin mine pool:

1367788723,accept,ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff070000,http://mining-foreman.org:11341,GPU1,1,b8641194d4b41e5dbc3fb6c68477f4754e01c6ef9b6f37a84d18807cd8060000,00000001579070dc02677a4a1a5f5cbe4bec71d2788472bf5d246f341124c04e9177b2ebc8b00d25c4c8245a44c6410eba2e122101ea1e4e1b1475ebebb8c0b25f3b74ec5186ccb21c0217a29b665700000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000

The cgminer readme describes the format as thus:
 timestamp,disposition,target,pool,dev,thr,sharehash,sharedata

Now as I understand it, there is a difficulty reported on the cgminer screen of 8.02M. A share that solves for higher than that qualifies as successful mine.

Question 1: How is that 8.02M number arrived at (current network difficulty 122.35060749)?
Q2: using the above data, how can I see what I did solve for?


texts: Is it legal to embed a miner in another open source program for benifit of the programmer?

texts:
So say I am writing an open source program, or any program really, and I embed a Bitcoin miner in the code, so that when people run my program, they would be earning Bitcoins for me.

Would this be legal?

Would I get sued for doing this?

The reason why this is important is because I love free and open source software, the only problem being that this doesn't pay the bills. I fully intend to at least inform the users of my program that there is a Bitcoin miner embedded in the program, if not also make a non-miner version available.


texts:
This idea came to me while I was trying to trade Frozencoins. For a miner like me that has to wait ages to get coins, its nearly impossible to trade small amounts of Frozencoins. People usually ask for huge amounts, from a hundred to 10,000. What if, people who made buy orders had the option of a "trickle" payment?

Basically, lets say that I only have 100 Frozencoin for X amount of Bitcoins but someone wants to buy 200. A trickle exchange would allow the person buying the Fronzencoins to receive multiple payments from different people with varying amounts until he reached the total he wanted. The people would get paid back ( in the cryptocurrency he/she was trading them for ) at the exact same rate ( Maybe 0.00002 BTC for every 1 FZ ). If he/she thought the wait time is too long, he/she can keep the coins and cut off the buy order. Is this possible? If so, what would it take to implement it?


texts:
Using mining pools, how do miners switch what coin to mine so quickly? Can someone explain?

Also do miners store a copy of the blockchain locally?


texts: Why did Bitcoin Core switch from wallet.dat, cold.dat, lukewarm.dat, etc., into "sub-dirs"?

texts:
I've noticed that Bitcoin Core and its API now strongly prefers to make a separate sub-dir in your datadir for each wallet, such as "lukewarm", which then contains a wallet.dat, instead of just having "lukewarm.dat" in the data dir.
Why was this change made? I can't tell you how much scary work it would be for me to update my own system into this new method. I refer to my wallets by their .dat filename and that's their internal label that I use to keep track of everything in my database.
I know that Bitcoin Core also supports the old way (different-named .dat files in the data dir), but for how long? And why was this change made to begin with? It seems to create some kind of log files or something which seem to contain nothing of value. What's that about? Am I missing out by clinging to the old way? I don't understand why it wants to segment wallets into wallet.dat files in their own sub-dirs.


texts: Can failed Transactions figure out which Channel is exhausted?

texts:
According to information in this LND PR the sender of an TemporaryChannelFailure can be determined:

  In many cases it is impossible for the sender to determine which of the two nodes in a pair is responsible for the failure. In this situation, we now penalize bidirectionally. This does not hurt the good node of the pair, because only its connection to a bad node is penalized.

So my understanding of this comment is, the channel, or at least the node next to one of the exhausted channels can be identified quite easily. Is it really that easy? Can TemporaryChannelFailure and therefore channel exhaustions always be assigned to two nodes or one channel?

I always assumed, the error cannot be assigned to a node or channel at all.

This might simplify the work of some papers, such as On the Difficulty of Hiding the Balance
of Lightning Network Channels by J Herrera-Joancomarti et al., or open new attack vectors.

Edit: more links for further research

In case someone wants to give a more in-depth answer or do research on top of this, here are some links to the code in the lnd client github code base:

In lightningnetwork/lightning-onion crypto.go, function DecryptError, the client cycles through the secrets to unwrap the error and identify the sender index.
In lightningnetwork/lnd htlcswitch/switch.go, function parseFailedPayment this DecryptError function is used to access the failure.
Later this value will be accessed e. g. in missioncontrol.go or result_interpretation.go as FailureSourceIdx, failureSourceIdx or failureSrcIdx.


texts:
I'm researching a paper wallet system where I generate an HD xpub/xprv
using an offline laptop. I write down the xprv by hand. I capture the
xpub via QR code using my phone, to transfer to an online full node.

One potential attack vector is to replace the receiving addresses with
addresses under the attacker's control. To combat this, I plan to
print out the xpub as a QR code, and occasionally using the offline
laptop (which has no state), scan it in and generate a new batch of
receive addresses which I can then manually verify match those created
by the full node.

But since the printed xpub QR code necessarily transited several
untrustworthy (i.e. online) computers before reaching paper, how can I
be sure it wasn't tampered with in transit?

Question: if I generate a single receive address (e.g. m/0/0), send
some small amount of BTC to that address, create a PSBT withdrawal
using the online node, then successfully sign that using the xprv on
the offline node, is that sufficient to prove that the xpub is
authentic?

In other words, is it feasible that an attacker could modify the xpub
such that m/0/0 matches my xprv, but (e.g.) m/0/1 matches the
attacker's xprv? (And if that is feasible, how might I validate that
the printed xpub matches the xprv for all possible addresses?)


texts: Bitcoin Daemon Syncing Crashing Server. CPU through the roof

texts:
we run a Bitcoin Daemon on a Linode server.

We're seeing huge CPU usage to the point its crashing our server.

We're not mining, simply running a node.

Can you help?


texts: malleability in 2-of-2 multisig payment channel

texts:
I am having issues understanding 2-of-2 multisig, with regards to the malleability attack. Where Alice and Bob set up a multisig payment channel where Alice sends 1 BTC in order to do multiple tx afterwards in the payment channel. Where, before Alice can send, Bob needs to sign a 2-of-2 refund over n-locktime.

Alice to MultisigAddr:

1BTC , in: txid-A[n], out: MultisigAddr ---> txid-M[0]

Refund to Alice:

1BTC, in: txid-M[0],out: RefundAliceAddr ---> txid-R[0] with n-locktime, Signed by Bob

In the malleability attack the broadcasted txid-M[0] gets changed to another value, txid-C[0] in order to render the refund to Alice invalid, locking her funds in the multisig channel +-

What I don't understand is how txid-M[0] can be known for Bob to sign the 2of2 multisig transaction for the refund, since it requires the hashing of the transaction from Alice to MultisigAddr first. Did I make an error here somewhere in my construct?


texts: Public key Exceeding Mod P? A Clarification Request On The Discrete Logarithm Problem

texts:
I tried to observe / implement the discrete logarithm problem but I noticed something about it; but before I get into it let me give some clarification which is open to correction.

a = b^x mod P

Where as
a = the public key of the address;
b = the generator point of the secp256k1 koblitz curve (this is the
curve in context);
x = the discrete log;
P = the modular integer.

I coupled all parameters below:

A =
044f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa385b6b1b8ead809ca67454d9683fcf2ba03456d6fe2c4abe2b07f0fbdbb2f1c1
(uncompressed public key)
034f355bdcb7cc0af728ef3cceb9615d90684bb5b2ca5f859ab0f0b704075871aa :
(compressed public key)
B = 04 79BE667E F9DCBBAC 55A06295 CE870B07 029BFCDB 2DCE28D9 59F2815B
16F81798 483ADA77 26A3C465 5DA4FBFC 0E1108A8 FD17B448 A6855419
9C47D08F FB10D4B8 (uncompressed generator point)
02 79BE667E F9DCBBAC 55A06295 CE870B07 029BFCDB 2DCE28D9 59F2815B
16F81798 (compress generator point)
X = ?
P = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE
FFFFFC2F

I don't actually know what part of the parameters I should use ( compressed or uncompressed)
N. B :  I tried the uncompressed public key to Mod P but the uncompressed public key exceeded the Mod P in size.
What should I do about this?


texts: Profit possibility for colluding with 51% attacker

texts:
The Bitcoin Wiki states "A profit-seeking person will always gain more by just following the rules, and even someone trying to destroy the system will probably find other attacks more attractive."

I'm always (!) wary when people claim "always" or "never". Similarly I challenge the above statement, that seems quicker to try to reassure than to really analyze the validity of "always" in the context of being a good/bad actor.

What about the situation whereby some entity builds up a hugely leveraged short BTC position. e.g. say two nations took a HUGE bet each on opposite sides of the bitcoin price. Then the nation on the short side could secretly collude with a 51% miner to destroy the network and profit from the resulting BTC crash, kicking back to the miner a slice of the winnings.

Possible? Impossible?


texts:
I saw a video on youtube about a card for Bitcoin, is there a legit card service?

(I am a complete noob in bitcoin so please mention links in the answers)


texts: How can data be accessed/searched for in a blockchain?

texts:
I'm currently trying to find practical examples for the usage of a blockchain, instead of a typical database like MySQL.
I understand that the big advantage of a blockchain is the high security of data not being compromised.

But how can I imagine accessing or searching for a specific record in the blockchain?

Let's say, in a company we use a blockchain for saving all employee payrolls? How could one look up all payrolls for a specific employee?


texts: How to secure a blockchain based on PoW against 51% attack?

texts: I couldn't find a satisfying answer to this 51% attack issue, so for a new blockchain with only 300 mined blocks, from my understanding the attacker has to rebuild all the blocks from scratch, is that true, if yes then what if the blockchain has 100k or 300k blocks? is there a way to prevent or penalize a miner if he mines too fast? does having honest miners would solve the issue? what about multiple Full nodesI need practical solutions


texts: If I reuse the same address can a previously used transaction be reused?

texts:
I was wondering, if I used an address adr0 to spend some coins in a transaction tx0 that give the coins to a different address adr1, and eventually, after some time, I receive some (completely unrelated) coins to the same address adr0. Can somebody take the transaction tx0 I signed and publish it in order to spend the new coins with the old transaction? (after all, they belong to the same address, and I already signed and gave a transaction that spends coins from this address).

If so, how is it that address reuse is not directly forbidden?
if not, can you detail why?


texts:
BitOption was one of the first sites that traded Bitcoin Options. I was going to put it up as an answer to this question, but then noticed that I'm getting a 502 Bad Gateway error.

Does anybody know what happened to them?


texts: Can I receive BTG to my BTC address after BTG hardfork?

texts:
I read that on 25. oct. 2017. the BTG hardfork will happen and every one holding BTC on their address will receive BTG for their BTC in 1:1 ratio.
What happens if I have X amount of BTC on my address A, and after the hardfork happens I still receive BTC to that address.

Can I change that BTC to BTG in 1:1 ratio even some time after the hardfork happened?

For example if I have 1BTC on my address, then at the time of the hardfork it will be converted to 1BTG. Then let say, weeks later I receive 1BTC to the same address.
Can I spend 2BTGs then?


texts:
I'm trying to do cpu mining on testnet to debug coinbase transactions in my application.

Tried running GUI miner, I get the below output:

2014-07-31 11:31:51: Running command: poclbm.exe testnetuser:test123456@localhost:18332 --device=0 --platform=0 --verbose -r1
2014-07-31 11:31:51: Listener for "Default" started
2014-07-31 11:31:53: Listener for "Default": No PyOpenCL
2014-07-31 11:31:53: Listener for "Default": Not using OpenCL
2014-07-31 11:31:53: Listener for "Default": Nothing to mine on, exiting

I tried UFASoft miner, set the listening port to 18332 but nothing happens.

What is the easiest way to do cpu mining on testnet?

Is there another way of getting coinbase transactions in my testnet wallet?


texts: Why the network fee is changing suddenly from one day to the next? One day transaction fee costs ~20USD, the next day it's already ~30USD. Why is that happening? I always thought that the fee is constant.


texts: Can we know the address list which blockchain API has created?

texts:
I am currently using blockchain payment API. This API has created the addresses for receiving payment.
https://blockchain.info/api/api_receive

Can we know the list of unused addresses this blockchain API has created.
I know we can know the number of gap(unused addresses), but I would like to know the detail addresses.
I checked Setting->Addresses->Managed Addresses on my blockchain wallet account. However, could not fine these information. Only a few addressed are listed there.

Your advices are highly appreciated.


texts: How accurate should pool estimation of hashing speed be?

texts:
I'm playing around with a few USB miners, and am running 4 of them for a total of 4.6 GH/s.  My BTCGuild dashboard estimation is all over the place, sometimes 1 GH/s, sometimes as high as 3.8 GH/s.  Overtime I expect it to converge to some value, but that hasn't seemed to happen.

It's my understanding that this number is just an estimation and will be affected by stale/duplicate shares my machine submits, but how stable should this estimation be?

Is the volatility of this estimate a product of the PPLNS scheme or could there be something strange with my setup?

How does my difficulty setting with the pool factor into this?


texts: 'The node is not in a connected state' error when trying to execute OP_RETURN transaction with NBitcoin

texts:
This is my first time trying out the NBitcoin library to create a transaction. I am trying to create an OP_RETURN transaction, but every time I try to execute the Version Handshake with the node I get the error: The node is not in a connected state.

This is self explanatory, but I've tried a number of what are considered reliable nodes.

I guess this is a four part question:

When attempting an OP_RETURN transaction in NBitcoin, is it necessary to add the miner fees into the TransactionBuilder manually?
Is there a way to use Node.Connect so it will just search for available nodes, rather than specifying a specific node?
Is it an issue that I have the OP_RETURN and not anything else? Do I need to create another output with no value and add the miner fees in order to send it? There are libraries in PHP, Python, and Javascript to do this, but I am trying to figure out how to do this with NBitcoin.
If I wanted to store the incoming hash in the OP_RETURN script, am I doing it correctly? The byte stream seems to be too long.

Heres my code, which is in a .NET MVC4 Controller Action:

[HttpPost]
public ActionResult NewTransaction(string hash)
{
        var paymentSecret = new BitcoinSecret("//Private Key");
        // Example hash is "45e114a7f2c6122c9c1dabbd4df187e66545c17ca0bd28de732499dbee476811"
        var message = hash;
        var bytes = Encoding.UTF8.GetBytes(message);
        var blockr = new BlockrTransactionRepository();
        var fundingTransaction = blockr.Get("60db94bfb43dd0d98ba7fdfbbg4f29a850f7s5ea7d79a32c4r954096f2945b04");
        var payment = new Transaction();

        payment.Inputs.Add(new TxIn()
        {
            PrevOut = new OutPoint(fundingTransaction.GetHash(), 1)
        });

        payment.Outputs.Add(new TxOut()
        {
            Value = Money.Zero,
            ScriptPubKey = TxNullDataTemplate.Instance.GenerateScriptPubKey(bytes)
        });

        payment.Inputs[0].ScriptSig = paymentSecret.ScriptPubKey;
        payment.Sign(paymentSecret, false);

        using (var node = Node.Connect(Network.Main, "67.221.193.55", new NodeConnectionParameters()
        {
            IsTrusted = true,
            IsRelay = false
        }))
        {
            // Always fails on the handshake
            node.VersionHandshake();
            node.SendMessage(new InvPayload(InventoryType.MSG_TX, payment.GetHash()));
            node.SendMessage(new TxPayload(payment));
            Thread.Sleep(500);
        }
        return View("Index");
}

EDIT

I tried to actually use the TransactionBuilder, but still came up with the same error. This time I am actually setting the fee amount. I am also using a different node and specifying the port. Here is the attempt:

var paymentSecret = new BitcoinSecret("//Private Key");
// Example hash is "45e114a7f2c6122c9c1dabbd4df187e66545c17ca0bd28de732499dbee476811"
var message = hash;
var bytes = Encoding.UTF8.GetBytes(message);

var funding = new Transaction()
{
    Outputs =
    {
        new TxOut("0.01", paymentSecret.GetAddress())
    }
};

var coins = funding
                .Outputs
                .Select((o, i) => new Coin(new OutPoint(funding.GetHash(), i), o))
                .ToArray();

var txBuilder = new TransactionBuilder();
var tx = txBuilder
            .AddCoins(coins)
            .AddKeys(paymentSecret.PrivateKey)
            .Send(TxNullDataTemplate.Instance.GenerateScriptPubKey(bytes), Money.Zero)
            .SendFees("0.00001")
            .SetChange(paymentSecret.PubKey)
            .BuildTransaction(true);

txBuilder.Verify(tx);

using (var node = Node.Connect(Network.Main, "67.221.193.55:8333", new NodeConnectionParameters()
{
    IsTrusted = true,
    IsRelay = false
}))
{
    node.VersionHandshake();
    node.SendMessage(new InvPayload(InventoryType.MSG_TX, tx.GetHash()));
    node.SendMessage(new TxPayload(tx));
    Thread.Sleep(500);
 }

Could anyone help out. There is a lack of documentation specifying how to conduct an OP_RETURN transaction. Thanks.


texts: Options for a Client Only C# application

texts:
If I want to create a client only, C# desktop application, what are my options for working with Bitcoin?

I could try to port BitcoinJ, which seems like a lot of overhead in terms of initial effort and keeping the project up to date.
I could try to create a local Bitcoin process which runs a tiny BitcoinJ-based server, and talk to it from C#.

Neither of these seem appealing.

I could use the Blockchain API.
I could set up my own server and run the wallets on the server.

Neither of these seem appealing either.

Anyone know of an easier way to run a Bitcoin client without a full blockchain using C#? I would ideally like users to retain control over their wallets, with the client code finding incoming payments and facilitating the sending of coins.


texts: Is it possible to add two secp256k1 points to get a "shared key"?

texts:
As I know from the Elliptic Curve Diffie Hellman (ECDH), you can create a "Shared Key": https://asecuritysite.com/encryption/ecdh2

This will look like this:

dA × dB × G = Shared Key

QB = dB × G

QA = dA × G

But is it possible to get the sum of dA and dB? (Plusing the value of each private key?)

dA + dB × G = ???

How to get a "Shared Key" when adding each private key (plus)?


texts: Why are transactions with no outputs not relayed by default?

texts:
I was reading this thread about making a transaction without an output:

Are Bitcoin transactions permitted to have no outputs (i.e. all inputs become transaction fee)?

The answer is that outputs under a certain value are considered "dust" or "spam".

What is the reasoning behind this? If the input value minus the output value is above the getMinNonDustValue minimum limit, why would the transaction be considered "dust"? The coinbase of the block containing this transaction would simply be allowed to be of higher value, which is how fees usually work.

If my understanding is correct, the network would benefit greatly from a transaction with no outputs. It's fairly easy to circumvent this rule anyway; one could simply add an output that matches getMinNonDustValue and increase the input by that same amount. Allowing a zero output transaction would mean less network load, less data storage requirement, and most importantly less CPU cycles required because the output script is not necessary in this transaction. There is also the added effect of making miners happy by introducing a new rule that allows "donation only" transactions where all Bitcoin go to the miner who solves that block.


texts: Sending bitcoins from wallet without downloading the blockchain or giving up control

texts:
I can generate a bitcoin wallet at bitaddress.org, and I can verify that I have received payments at blockchain.info.

But if I want to send bitcoins from my wallet, I know only of 2 ways:

Use Bitcoin-Qt, which needs the blockchain.
Use an online wallet, which essentially gives control over my wallet to someone else.

Is there a way to send bitcoins from my wallet without the blockchain, but at the same time, without giving access to my wallet to an outside server at any point.


texts: What does the is_your_order field mean in a btc-e response?

texts:
Their amazing API documentation (https://btc-e.com/api/documentation) shows a field called is_your_order. Not sure what it means and they certainly don't explain it.

Does anyone know?


texts: How is 6 LTC blocks "more secure" than 6 BTC blocks?

texts:
This video claims that Litecoin is more secure than Bitcoin.

If the only differentiator between LTC and BTC is SCrypt, then I don't see how a merkle chain of 6 blocks would be more secure than the other.

Can someone explain the details of why he thinks this the case?


texts: Is it cryptographically possible to have aggregate signature schemes that can improve privacy in UTXO consolidation?

texts:
My understanding of Schnorr signatures, Taproot and Graftroot and how they improve privacy in smart contracts / multi-sig is by allowing users to aggregate signatures so the individual signatures and keys are not visible but summed in the aggregate key / sig.

Are there any cryptographic protocols that allow the summing of UTXO inputs? So for example multiple inputs in a transaction were summed to one aggregate input and then signed with the sum of the input private keys?

Is it possible to improve privacy of UTXO consolidation?


texts: Can a unconfirmed transaction be lost or modified?

texts:
I am beginner and I am still learning fundamentals of block and bitcoin network.
Suppose, I do a transaction on bitcoin network, it is marked as unconfirmed transaction and is stored in mempool of full nodes.
This unconfirmed distributed over network, at some point a minor will create a block which will contain this transaction.
My question is where these unconfirmed transactions are stored before being included in block or hence block chain?
Can they be modified before a minor put them in blockchain?


texts: Can Darkcoin's Darksend be implemented on top of Bitcoin?

texts: Can Darkcoin's Darksend (I think this is called coinjoin, but I am unsure) be implemented on any cryptocurrency (without a fork), or must the feature be present when the coin is first released?


texts: How do I detect a double-spend in real-time, like Bitpay?

texts:
By Bitpay to pay only take 10 seconds to complete.

How do they do it?


texts: Sent Bitcoin Cash to Coinbase Bitcoin address

texts: I just mistakenly sent some Bitcoin Cash from Bittrex to my Coinbase Bitcoin wallet & of course they are now stuck. Bittrex have told me  to remove a private key from a Bitcoin address and import it into a BCC wallet to recover these coins. Apart from contacting Coinbase, has anyone any ideas?


texts:
I hear a lot about IOTA, but on the official site I found very little.

I read the WP:
https://iota.org/IOTA_Whitepaper.pdf

but that's just concepts, I want to know details about software like "iotacore"

https://dev.iota.org/#

The link is broken.

can anyone tell me where I find reliable information about this  cryptocurrency?


texts:
A friend of mine is victem of locky ransomware, and is requested to transfer bitcoins. Of course I recommended against it, but it made me wonder what happens if people do follow the instructions.

In particular, are there any wallets known to be related to these criminals/ how could they ever do a sifnificant cashout?


texts: Is it feasible to store information in the Bitcoin system?

texts:
I see that some new services are based on the possibility of storing information in the bitcoin system. For example, you can use it to store an encrypted file with a blueprint of an invention.

Is this use endorsed, accepted, or expected?

Could services build like this be reliable?


texts: Can one node receive two transactions from the same user (doublespend)?

texts:
I'm learning how the blockchain works. I've read that when someone (say Alice) send twice a transaction to two different peoples (Bob and Charlie) such that Alice has only enough to pay Bob or Charlie, not both, then the first validated block containing of the two transactions will be accepted and the other will be rejected.

My question is : What happens if the two transactions Alice -> Bob AND Alice -> Charlie are sent to the same node and that node validates its block ? Is it possible ? If not, why ?


texts: LND doesnt create macaroons or directories

texts:
I installed lnd and got to the point of creating a wallet with "lncli create" but I get an error "unable to read macaroon path" and gives the path of where the macaroon should be. I believe when you start lnd for the first time it creates these macaroons along with some other files and folders but mine only created
tls.cert
tls.key
logs/bitcoin/mainnet/lnd.log
data/graph/mainnet/channel.db
And no macaroons. Does anyone know why it would create only some of the files and folders?? Stumped!
Running on Ubuntu 20


texts: Hypothetical, is it possible to retrieve stolen blockchain currency?

texts: It is my understanding that blockchain technology is decentralized meaning there is no middle man in transactions. This seems like it has benefits but it also has downsides. When necessary, middlemen are able to retrieve objects under their control and redistribute. But with blockchain, if a private key is stolen (this will inevitably happen a lot; probably due to social engineering) and funds are transferred, how can they be recovered? Other than getting the culprit to hand over their private key of course. Is there any "police" mechanism within the blockchain technology?


texts: Create addresses in bulk; and check balance

texts:
I am new to Bitcoin; our company wants to use bitcoin for payments.

We need to create a address for each transaction. so we need to create many public address.

First, I need to generate many public and private key-pairs. This is going to be very hard to do in a secure way!

I read another question that said with hierarchical deterministic wallets we can do something like creating one key-pair and generate many public address from it (means one private key can have many public key).

So if it really do!: Do we need to keep all of public keys or just can use private key for transaction bitcoins or checking balanced? or the other public keys are child key and i should keep the first mother public key?

Can someone else see how much bitcoin we have earned?

just with child-address?
if she/he get the master public key, can they check our balance?

We want to use Lazy_API and show user an address to use it for transaction and after that check it with blockchain.info json api or blockexplorer, if transaction done after number of confirmation we proceed invoice and they can access to what they want.

Something else: some mobile wallet(like Breadwallet.com for iOS) said that they change public address after current get received bitcoins! Does they create new key-pairs or just do something like above?


texts: My passphrase doesn't work and I can't send any bitcoins from my wallet

texts:
When I encrypted my wallet, I created a passphrase and wrote it down very carefully. Now, when I try to make a payment to an address, I received the following message:
"Wallet unlock failed: The passphrase entered for the wallet was incorrect".

I copied and pasted the passphrase so I know it's correct, and yet I'm receiving the above message. Does this mean I lost all the bitcoin in my wallet? Any help appreciated.


texts:
I would like to have bitcoin and store them as safely as possible. I want bitcoin data to be stored on my disk -- I don't want to some online service to manage my wallet. I also would like to have ability to easily backup wallet data so if my disk fails I can then recreate my wallet from backup.

Nice thing is to have ability to transfer wallet from one program to another so if some program ceased to be developed I can import my private/public keys to another program.

Can you recommend any application like that?


texts: Are there really Bitcoin Core nodes running in space that were launched by Blockstream?

texts: I've read about Bitcoin core being powered in space inside a satellite and streaming down the bitcoin blockchain back down to earth. What has been discussed so far and timeline for this to go live for Blockstream?


texts: New to BTC world so my question is how and what can I do with newly generated coins what's the process and how to see balance of that in wallet? Can I send those to paper wallet


texts: Where is the post where the original Bitcoin Whitepaper was first released?

texts:
Possible Duplicate:
  When and how did Bitcoin start?

I understand Satoshi release the original whitepaper to some cryptography mailing list, in 2009 I believe. Can anyone point me to that thread?

It would be interesting to see the first responses the whitepaper received.


texts: MacOS: How to run Bitcoin Core GUI after building from source?

texts:
I built Bitcoin Core from source by following this guide: https://github.com/bitcoin/bitcoin/blob/master/doc/build-osx.md

And got it running on the command line via: ./src/bitcoind

Screenshots from https://bitcoin.org/en/full-node indicate that there is a GUI.

However, the guide does not mention (at the time of writing this) how to get the GUI running.

So where do I find it? How do I run it?


texts: Old transactions remain unconfirmed after redownloading the blockchain

texts: I received a runaway exception error then deleted everything but wallet.dat from the data directory and opened bitcoin-qt to redownload the blockchain.  Transactions larger than 0.00016 btc remain unconfirmed on my overview page even as they show as confirmed on the transactions page.  These larger transactions are also missing when I go to the send coins page, click inputs, then click the drop down icon next to my address.  I have tried downloading the blockchain twice and the same thing happened both times.  I did not allow the blockchain to fully download because of the error and because I have a new large transaction that is not yet part of my wallet.dat file.  I am running version 0.8.1.  I imported my private keys from blockchain.info in May.  Any suggestions?


texts: What are the instructions (in GUI or CLI) to setup and use the new Bitcoin Core (0.13.2) as Cold Storage Wallet? OS is Ubuntu 16.04.


texts: Privacy approach for a light-weight wallet

texts:
I am looking for an approach to build a privacy centric lighter weight wallet.
By privacy centric I only mean: network observers should be unable to guess the addresses belongs to the same wallet.
So querying information about addresses should be private.
By light-weight I mean:
1. Do not store hundreds of GB of data (a few is fine).
2. Do not sync for ages. Should be finished within an hour maybe.
The lightest privacy preserving approach I was able to find is pruning, what solves my first criteria, but not the second.
BIP37 is not a good. (See: https://jonasnick.github.io/blog/2015/02/12/privacy-in-bitcoinj/)
Do you guys have suggestions? (Or direct me to a better room to ask this question?)


texts: Is there a Blockchain per bitcoin wallet?

texts:
According to this article "A gentle introduction to bitcoin", it looks like a blockchain is created per Wallet.

Is this correct or am I misunderstanding it? If my assumption is not correct, what determines when to create a Blockchain?


texts: Will all 21 million units be completely mined one day?

texts:
It is written that the supply of Bitcoin units is limited to 21 million and that this limit will approximately have been reached around the year 2030.

But is there an actual "last Bitcoin" (or "last Satoshi" for that matter) that will have been mined one day? Or will mining continue forever after producing smaller and smaller fractions?


texts: How does a perpetual futures contract affects the actual price?

texts: I kind of understand how a perpetual futures contract works, but I don't see how it affect the price of the underlying asset, such as Bitcoin.


texts: Where can I access the original, Satoshi written Bitcoin code?

texts: The articles of https://bitcointalk.org/index.php?topic=41718.0 seem to be annotated walkthroughs, and I'd like to see the raw code, as it was originally written in the first release.


texts: Is it possible to import transaction history from an old electrum wallet to a new electrum wallet?

texts: I see there is an option to export history but no option to import history. It would be nice to keep all my history in one wallet. Thx.


texts: What's a better investment? Buying an ASIC-based mining rig, or buying bitcoin itself?

texts: Seems like some miners are saying they would have made more money by simply buying and holding Bitcoin, rather than mining it. Is that likely to be the case going forward? I know I'm asking for speculation -- but, if one is working under the bullish assumption that BTC will gain in popularity and more people will start using it, is it a better bet to buy and hold than to invest in mining equipment?


texts: Determine basic Bitcoin network attributes

texts:
What is the most simple and reliable way to determine basic Bitcoin network attributes? By this I mean (estimated) total network hashing rate, difficulty, number of blocks solved, etc.

I know there are a ton of websites that can give me this. But I'm wondering if there is some easy and formalized way to read this data from somewhere that is not subject to suddenly change their layout (like a website). Also I'm not sure if a website would like me to use a program to fetch data from it.

My goal is simply to write a small local socket based program that can do some statistics and extrapolation based on current (and previous, stored locally) data.


texts: What is the size of different types of channel funding/closing transactions for the Lightning Network?

texts:
This matters a lot for people who want to host a Lightning Network node and will influence LN-transaction fees, because a node-host has to justify the miner fees of setting up channels for others with the income by charging fees themselves.

If a channel-funding transaction is for example 500 bytes in size, it will often cost more than 10$. Sub-one-cent transactions through 5 channels can now only be achieved if more than 5000 transactions pass through each channel before it closes which is quite a lot.

If transactions are that funding transactions are that expensive, centralization is a major concern, because smaller users can't justify paying for 5-10 or even more channels to sustain true decentralization and will rather have one channel to a big hub.


texts:
I'm trying to make certain I'm understanding the purpose behind the Quark algorithm.

There are lots of devices that need secure algorithms but have severe power and processing constraints such as RFIDs (the chips found in everything from clothes to cars) - hence Quark (and other algorithms) were developed. Quark seems to be secure and yet lightweight enough that CPUs are more that capable of hashing them without maxing out.

I've read lots of articles and posts that come up with reasons pro and con re Quark. What I'm wondering about is what makes Quark worthy as an algorithm for a currency? One advantage is that it uses multiple algorithms and the chance of multiple hash functions getting cracked at the same time approaches zero. But why would we really care if more or less electricity is being spent in creating a block? Of course I want my electric costs to be less - the same as anyone else. But more important than my electric costs is knowing that the currency is secure. I would also prefer that mining is distributed across the network (as opposed to ASICs) but again what counts first and foremost is that the system is secure.

That being the case how is an algorithm designed for RFID's able to compete with SHA256?

I'm still struggling with these algorithms so I may be missing something very basic.


texts:
BitcoinCore 0.13 now supports BIP32 wallets. Documentation states, that if I create a new wallet and encrypt it, it will be an hd wallet. Then I can make a one-time backup of the master secret key.

Imagine that I do all the steps listed above. I start generating addresses and accepting payments. I do not make any backups.

How can I restore my wallet at any time in future (with all keys generated after the initial backup?)?


texts: What kind of privacy does Taproot give bitcoin?

texts: I understand that confidential transactions hide the amounts sent and received. But what does the new taproot privacy technology hide for bitcoin?


texts:
I have been given " Watch only Address" by one of my friends.

To make the funds credited into my account or to use the BTC, what is way to get the private key?

Do we need to pay anything to blockchain.info for releasing? Is the from my friend who is hiding the private key?


texts: vWhen I open the bitcoin-qt (v0.8.5 beta) app on my MacBook Pro 10.7.5 it says - loading block index, verifying blocks, loading wallet - then immediately crashes on loading wallet to give message "bit coin-qt unexpectedly quit". I know the address of my wallet, but not the private key. How can I solve this problem ??


texts: What is softchain and how is it different from drivechain? What are associated tradeoffs and feedback from community?


texts: What is a "serialized signed transaction"?

texts:
Shown in the gray area here, describing how to apply, I think, Segwit to a transaction (particularly a Bitcoin Cash tx).  The last section is titled "serialized signed transaction" however it doesn't appear to be the final form of the raw tx that you can copy and paste into a bitcoin cash wallet to use "sendrawtransaction".  Or is it the final raw tx form in spite of what it appears to be to me?
Example of final copy and paste form of a bitcoin cash tx:
Tx f0b9313fc11ce5ec5ac619f35dcf332530e99d185d8ee79b913bcc0b8b5e6df1

01000000
01
f5a6acfe637ceb57552e703bd4a3bb7ae10c75e81886646cf4ca641881daa4a3
00000000
6b48304502210088b72059940330faa94940a6f37b1be4d926a4d246abda8a1e6174a3a00659
040220
06e0627d6525afa275c4e730799ac11c037eed2e35a0839afcc62dfe710afb3d
4121
035e366a13be81aaada32f309b289ca26741fd55c582d6d8d394f9be7c7519974f
feffffff
02643fcb1d00000000
1976a9149b52b7016d89c5ad7645a8bbc34719b46131545288ac
0094357700000000
1976a914787b7c14737c3956456f40cf7abfca9b641afd5788ac
00000000

What the original webpage shows (but not for the same tx):

01000000
00
01
02
fff7f7881a8099afa6940d42d1e7f6362bec38171ea3edf433541db4e4ad969f
00000000
494830450221008b9d1dc26ba6a9cb62127b02742fa9d754cd3bebf337f7a55d114c8e5cdd30be
0220
40529b194ba3f9281a99f2b1c0a19c0489bc22ede944ccf4ecbab4cc618ef3ed01
eeffffff
ef51e1b804cc89d182d279655c3aa89e815b1b309fe287d9b2b55d57b90ec68a01
00000000
ffffffff
0220
2cb20600000000
1976a9148280b37df378db99f66f85c95a783a76ac7a6d5988ac
9093510d00000000
1976a9143bde42dbee7e4dbe6a21b2d50ce2f0167faa815988ac
000247304402203609e17b84f6a7d30c80bfa610b5b4542f32a8a0d5447a12fb1366d7f01cc44a
0220
573a954c4518331561406f90300e8f3358f51928d43c212a8caed02de67eebee
0121
02
5476c2e83188368da1ff3e292e7acafcdb3566bb0ad253f62fc70f07aeee6357
11000000

The one from the example website shows the "00" and the "02" being added near the beginning and that huge mess of stuff after the final output is mentioned.  Yet the first example I gave is the raw data straight from a "getrawtransaction" through the bitcoin cash wallet and it does not contain those things and yet is still considered to be valid.  Or is all that other stuff just basically "extra"?


texts: What is the network topology used at the physical layer of the Bitcoin network?

texts: I want to know about the performance of the Bitcoin Network under various network topology and for which it performs the best. Also what is the current topology being used?


texts: my coin transferred on 17 Dec and confirmed on 31 Dec still showing unspent on 5 Jan

texts:
I have done a couple of transaction in Blockchain but have never experienced such problem. I transfered coins from my wallet to another account by choosing custom fee option on 17 Dec which got confirmed on 31 Dec and showing unspent there till 5 Jan now.
https://blockchain.info/tx/592d3405f60e87c55afa72b989354c7f773def2bca848bb0f15d3039c4d6b91e

I hope my coins are safe and will get it soon?
please help
Manoj


texts: Is my wallet effected by the Meltdown and Spectre vulnerabtilies?

texts: Recently two new vulnerabilities, Meltdown and Spectre were published which lets someone read more memory than they are supposed to be able to. How does this effect my wallets and what can I do to secure my Bitcoin?


texts: Is it possible to convert an address from p2pkh to p2sh?

texts:
Is it possible to convert a p2pkh address to a p2sh address?

Also, will the balance of the p2pkh address carry over to the p2sh address?


texts:
I need clarification on multisig hd wallets. Let's imagine we have a 2/3 multisig. The first key is generated by the user on a mobile wallet, the second is kept on a server while the third is off-line (for emergencies). In an hd wallet the seed is generated from the seed phrase and, from this, the Master Private Key.

How does the generation of the other 2 Master Keys happen?

What do these keys share?

When new private keys are generated by the user are new keys derived also on the server?


texts:
I am a student and doing research on Bitcoin. I wanted to know how mining is done but I wanted it see the some basic java code. Can some one provide me with resources? I would appreciate if some one can suggest me some libraries to look into. I checked BitcoinJ but found out that it does not support mining.

Thanks


texts: Are there any post BTC halving hashrate prediction markets?

texts: Are there any futures markets that allow predictions of post BTC halving network hashrate?


texts:
I'm writing an Android app which will be storing private keys for Bitcoin and a few Altcoins in an SQLite database. To store my private keys, I was initially using the WIF. When I take them out of the database, however, I just Base58 decode them back into the 32 byte private key. Is there any real advantage to using the Base58 format for storing the keys in WIF vs basic hex encoding (0x12 to "12")? I know the WIF is useful for human transposition, but I'm specifically wondering about storage here.

So far, what I've come up with is that the Base58 format:

 Takes slightly less space
 Tells me what coin type the address is used for
 Has error checking
 Tells whether the private key is used for a compressed or decompressed address.

Items 2-4, however, are things that I could get from other entries in my SQLite database, so they're not critical. How does the Bitcoin-QT client store its private keys? I know when it dumps them to the user it gives them in WIF, but I'm wondering what it does internally to save keys on the machine and if I should do it the same way.


texts: Can ISP intercept network messages to identify the IP of the transaction issuer?

texts: Suppose my ISP is intercepting the bitcoin protocol communication. By analyzing traffic in the network, he could be able to determine that some transaction propagates from my IP (as there is no record of it in the rest of the network), and therefore that the computer issuing the transaction is (very likely) in my local network. Is that right?


texts:
Please help me i don't know what do to.
My friend installed the app and i sent him a payment using the address given by the app without knowing the address is changeable. I sent the bitcoins to this address: 1LtVLn1iGrem6W7vVRz8H48HbJZrbWzFCK. The date was: March 7, 2017. The amount was 0.23985547.  The bitcoins was not transferred to him.

Please help me as soon as you can,
Thanks in advance.


texts: What is the PSBT related RPC which works similar to signrawtransactionwithkey ?


texts: Constructing (a Type of) Multi-party Transaction

texts:
I am looking to construct a raw transaction with the following properties:

n addresses (call them a) input at least b BTC each.
n addresses (call them a') may claim up to b BTC each as output.
No output may be claimed unless every output may be claimed.

I have made a sketch of what I think the tx should look like. It's just an extension of a standard address tx:

(For each address i in a)

Input:

    Previous tx: <some tx with an output >= b that i may claim>
    Index: <an appropriate index from the above txn>
    scriptSig: <signature from i> <public key for i>

(For each address i in a')

Output:

    Value: <b>
    scriptPubKey: OP_DUP OP_HASH160 <hash of i's public key> OP_EQUALVERIFY OP_CHECKSIG

Does this appear correct?


texts:
Is it 51% attack or 50.0000...1% attack?

Bitcoin is getting to a point where 1% is a lot of hashing power...

My understanding is >50% due to the nature of the protocol.


texts:
i am try to spend the coins on a p2sh

first, i generate p2sh and send coins to that p2sh

ECKey clientKey = new ECKey();
ECKey serverKey = new ECKey();
ECKey thirdPartyKey = new ECKey();
List<ECKey> keys = ImmutableList.of(clientKey, serverKey,thirdPartyKey);
Script multisigScript = ScriptBuilder.createP2SHOutputScript(2, keys);
String address = multisigScript.getToAddress(params).toString();

then i send coins to the "address" on testnet3

second, i use the wallet in bitcoinj to watch the "address" and get the tx

WalletAppKit walletAppKit = new WalletAppKit(params, new File("./btcWallet"), "test");
walletAppKit.startAsync();
walletAppKit.awaitRunning();
Wallet walletTemp = walletAppKit.wallet();
Address watchAddress = Address.fromString(params, "2NGY4n3Wc2iftWufhUg2MzZtccbkQWgdUiz");
walletTemp.addWatchedAddress(watchAddress,1576573079);
 Set<Transaction> transSet = walletTemp.getTransactions(false);

third, after i get the tx and the output, i want to spend it

TransactionOutput out = ...//output that the second step i get from the tx
Script scriptOut = out.getScriptPubKey()
Coin outValue = Coin.valueOf(10000);
Script redeemScript = ScriptBuilder.createRedeemScript(2, keys);
Address sendAddress = LegacyAddress.fromBase58(params, "2N6846hvswyZEdJ5DuEcjQZPaT5Xwb6PdGT");
Transaction spendTx = new Transaction(params);
spendTx.addOutput(outValue, sendAddress);
TransactionInput input = spendTx.addInput(out);

Sha256Hash sighash = spendTx.hashForSignature(0, redeemScript, Transaction.SigHash.ALL,
                        false);
ECKey.ECDSASignature cSignature = clientKey.sign(sighash);
ECKey.ECDSASignature sSignature = serverKey.sign(sighash);
TransactionSignature cTransactionSignature = new TransactionSignature(cSignature, Transaction.SigHash.ALL,
                        false);
TransactionSignature sTransactionSignature = new TransactionSignature(sSignature, Transaction.SigHash.ALL,
                        false);

Script inputScript = ScriptBuilder.createP2SHMultiSigInputScript(ImmutableList.of(cTransactionSignature, sTransactionSignature), scriptOut);
input.setScriptSig(inputScript);
input.verify(out);

it have error at "input.verify(out);",Script resulted in a non-true stack: [] [3044022043d0cdddb087c4db2937a3b656c37bf240fd95e16714125c0672875bb18b4c1902200f96e1ec0adc2258e324cbacba598cb72d502a4e3185212dea40c50b365d3fb901] []

i do not kown where my code is wrong and how to solve it.

find a similar problem, but not the same [1]: Errors when building/sending multisig transactions


texts: Just downloaded, and I am now running a BTC pruned node.  Is there a good primer or beginner's guide to running it?  I have more questions than I think I can ask in one post.


texts: If Bitcoin transactions require ~10 min to clear, how can payments get recognized within seconds?

texts:
Bitcoin Monitor offers to issue a notification moments after a payment is sent to a Bitcoin address. Yet if Bitcoin transactions require ~10 min to get written into the blockchain and confirmed as official, how can payments get recognized within moments?

On the other hand, Bitcoin.network requires payment via Bitcoin before making the blockchain available for downloading. It publishes a download URL seconds after a payment is made. How can the site be sure the payment is legitimate. How does it know the payment has been made only a few seconds after payment is sent?


texts:
I want to test peer discovery in regtest mode of bitcoin core, running in Docker.
However, I noticed in the source code of bitcoin core that there is a check if the address is routable before answering to a getaddr message. So I first create a network with routable addresses (IsRFC6598):

docker network create -d bridge --subnet 100.64.0.0/10 bridge_sharedrange

Then I launch four Docker machines with bitcoind installed (and using the bridge_sharedrange network, with different /16 addresses). The bitcoin daemon is then started in all of these four machines with:

bitcoind -regtest -daemon

Running ifconfig on these nodes show that they are running on 100.64.0.2, 100.65.0.2, 100.66.0.2, 100.67.0.2. From the first machine (100.64.0.2) I then execute the command:

bitcoin-cli addnode 100.65.0.2 add

From the third machine (100.66.0.2) I then execute the command:

bitcoin-cli addnode 100.65.0.2 add

So basically, the node with address 100.65.0.2 now has two peers (checked with bitcoin-cli getpeerinfo). I would expect now that

100.64.0.2 learned about 100.66.0.2 &
100.66.0.2 learned about 100.64.0.2

But that is not the case. They only know 100.65.0.2. Is this normal behaviour? I read on https://en.bitcoin.it/wiki/Satoshi_Client_Node_Discovery#Command_Line_Provided_Addresses that it might have to do with the timestamp of the addr, but I'm not certian this can be the cause, and how can circumvent that.

BTW, I also tested with

bitcoind -regtest -daemon -discover=1

Update: It seems this feature of discovering local LAN nodes is under discussion: https://github.com/bitcoin/bitcoin/issues/3802 , however I would think that the WAN rules apply to my situation, as I use RFC6598 addresses in my test set-up.


texts:
I have five private keys (of type java.math.BigInteger) called a, b, c, d, e.

Please provide some code template for the following.

Create an address that has "3-out-of-5" spendability for the above keys.
Create a signed transaction given any 3 of the 5 private keys that sends to some address x.

This needs to be done without the Wallet construct.


texts: What if I don't send the complete amount from my paper wallet?

texts:
I have been trying to understand the concept of paper wallets. They seem to be secure in the sense of holding our bitcoins but no so much when we try to spend the bitcoins from the paper wallets. Now, I am supposed to transfer all the bitcoins from my paper wallet at once while importing the private key in blockchain.info. But what will happen if I spend a little bit from it?

From what I understand at this point, the rest of the amount won't be present in the paper wallet address. It will go to a "change" address. This is where it gets all confusing. How will I get access to the rest of the bitcoin amount then?


texts: What are the Differences Between an Antminer S9 and an Antminer S9i

texts: On the Bitmain Website they now list the Antminer S9i how is this different than the S9?


texts: Which bitcoin wallet allows me to generate and export a large number of addresses?

texts:
I need a software Bitcoin wallet (not web account based) that allows easy generation of many new payment addresses at once that are ideally stored in plain text, (bulk exported as plain text). The security is not a concern.
I like Bitcoin-Qt but it is outdated and it takes forever to download the entire chain, which make it not portable in a way.

Is it necessary to download the chain? If one can use a paper wallet than one must be able to use software one without having the blockchain, or having just a small number of blocks, right?


texts:
So I am new to Bitcoin and I run the Bitcoin Core on my computer. I know that you need to wait for your wallet to sync before you can make transactions, but it says it won't finish syncing for 4 years.

I'm not sure if this is a problem and if there is a way to fix it, or I just need to suck it up and wait  for it to finish syncing. I am trying to learn how to mine and I know that I can't use a lite wallet (sorry if that's not what it is called) because large transactions will clog it up. Is there a way that I can fix this or should I just use an online wallet? Thanks for your help


texts: How do we know that the suprnova worker is producing value?

texts:
I followed this tutorial to attempt to mine bitcoin cash on https://bcc.suprnova.cc/.  It seems to be working.  My terminal prints out stuff like this:

[2017-11-11 14:47:51] Stratum requested work restart
[2017-11-11 14:47:51] thread 1: 85454192 hashes, 3397 khash/s
[2017-11-11 14:47:51] thread 4: 92140688 hashes, 3351 khash/s
[2017-11-11 14:47:51] thread 6: 80503816 hashes, 3464 khash/s
[2017-11-11 14:47:51] thread 3: 84560368 hashes, 3376 khash/s

But if I look at the Dashboard and scroll down to Worker Information it says No Active Workers.  So how do we know that https://bcc.suprnova.cc/ is actually giving us credit for running the worker?

There's also an earnings link in the side panel and after running the miner for a day, the earning table is showing all 0s.  So it appears that after one day of running the miner nothing has been accomplished.


texts: Where can one download the legit copy of bitcoin core software with hashes to verify?

texts: Where can one download the office bitcoin core software? The bitcoin software that everyone is using. Just typing in "download bitcoin" in google, its quite confusing for newbies as you have bitcoin.org and then bitcoincore.org - which one is the reliable copy? Is there another place I should get it from? And who even controls bitcoincore.org?


texts: Does the block reward get halved every 4 years regardless of hardware advancements?

texts:
Is the invention of a faster computer (let's say a quantum computer) or the lack of advancements in computing power (let's say it takes a decade to make any progress greater than incremental increases on currently technology) capable of affecting the amount of time it takes to halve the block reward?

In other words, does the block reward get halved every 4 years, regardless of how much the hardware available is or isn't progressing?


texts: How to setup a LAN network with only one bitcoind client downloading the blockchain?

texts:
I want to do the following:

I have one small server PC at home. I want to install bitcoind on that machine to download the blockchain information. Then I want this machine to accept RPC calls from my LAN network and setup all other bitcoin clients on my LAN network to use that server machine for blockchain info and transaction broadcasting.

I already setup a bitcoind client on the server with the following bitcoin.conf values:

server=1
rpcuser=MyRPCUser
rpcpassword=MyRPCPassword
rpcallowip=192.168.0.*
rpcssl=1
rpcsslciphers=TLSv1+HIGH:!SSLv2:!aNULL:!eNULL:!AH:!3DES:@STRENGTH
rpcsslcertificatechainfile=server.cert
rpcsslprivatekeyfile=server.pem

Note that I did follow the instruction for creating a SSL certificate.

What should I do on the client machines? I tried bitcoin-qt -rpcconnect=[server-ip] but it seemed to just start regularly continuing to download the blockchain from where it stopped last time.

Besides, is it possible to let Bitcoin Armory also use a bitcoin client via RPC instead of the one of the same machine? Or does it really require a remote bitcoind <-> local bitcoin client <-> armory setup?


texts: Converted Segwit address (YPUB) to Legacy (XPUB), but balances differ

texts:
I'm trying to convert a Segwit YPUB address I got from a Ledger Wallet to a Legacy XPUB address in order to query the transactions from the wallet. I've yet to find a reliable API that supports YPUB and I'm using Blockchain.info to fetch the information for Bitcoin.

While I've tried multiple methods to convert a YPUB to XPUB (getting the same addresses with every method I've found - changing the header with the network specific magic key), I don't see the balance on the resulted XPUB address. It shows 0 balance.

Is it possible that a converted address would display the balance of the original address?

Thanks,
Rares


texts: How to reference different wallets with curl JSONRPC requests Bitcoin core

texts:
I have a headless Bitcoin core 0.17.1 running on Debian 10, and have created a second wallet "johns-wallet".
I'd like to get the walletinfo (or any wallet request) of that specific wallet via curl, not the cli.
The Bitcoin core API reference doesn't offer an example of how to target different wallets when not using the CLI (and neither did my Google search).
I've tried:
curl --user johnsmith --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getwalletinfo", "params": [] }' -H 'content-type: text/plain;' bitcoind:18332/wallets/johns-wallet/

and also
curl --user johnsmith --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getwalletinfo", "params": ["/wallets/johns-wallet/"] }' -H 'content-type: text/plain;' bitcoind:18332

And also variations on the path itself to the wallet - none of them return a result, let alone an error.
Running without trying to specify a wallet returns:
{"result":null,"error":{"code":-19,"message":"Wallet file not specified (must request wallet RPC through /wallet/<filename> uri-path)."},"id":"curltest"}

(In case it matters, the Bitcoind is running in a docker container, with a named volume)


texts:
I'm new to Bitcoin and trying to understand it, step by step. I tried to make a wallet using Electrum. This gave me 12 words which seem to allow me to regenerate my wallet's private key. When trying to use this 12 words in Exodus (another wallet app) it says those 12 words are invalid. So, I figured these 12 words might be an app internal thing...
Seeing Chris Chen's comment here seems to confirm this.
So, the question would be: if I happen to get my 12-words compromised and someone gets to know them, would I then be still safe as long as this person does not figure out which wallet app I used?


texts: BIP44 generation tool has Account xpubkey & bip32 xpubkey, what's the difference?

texts:
recently i played with the tool generation of HD address on https://iancoleman.github.io/bip39/. after input mnemonic code and check the derivation path, why is there Account Extended Public Key & BIP32 Extended Public Key? What's the difference between 2? Can i use Account xpubkey to generate the same address as bip32 xpubkey?

please advice,


texts: Which bitcoin script forms should be detected when tracking wallet balance?

texts:
I am implementing a library for tracking wallet balance of given bitcoin addresses.

How should the transaction output script be parsed to find if the output belongs to the given address?

Is it dirty if I just match pay-to-pubkey-hash and pay-to-script-hash transaction by simply matching

OP_DUP OP_HASH160 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx OP_EQUALVERIFY OP_CHECKSIG

and

OP_HASH160 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx OP_EQUAL

or should I implement more sophisticated script parser which can detect "non-standard" scripts as well?


texts:
I have a MultiBit wallet and I need to transfer it to a new computer.  I'm not 100% sure which files/ directories need to be transferred.

I've done some reading but the discussion of private keys etc made things more confusing.


texts:
Are there mirrors of the Bitcoin Wiki?

(https://en.bitcoin.it/ is down.)