texts: What is "safe mode" and how does it affect RPC Commands?

texts:
The source code here has a list of RPC commands and a "okSafeMode" parameter.

What is the purpose of this SafeMode and how does it affect the usage of the client?


texts: Format of a block key's contents in bitcoind's LevelDB?

texts:
I am trying to use bitcoind's LevelDB block index files (that are stored in blocks/index) to find the file (e.g. blk00029.dat) and byte position of specfic blocks.

Thanks to questions What is the database for? and What are the keys used in the blockchain levelDB (ie what are the key:value pairs)? I know where to look, however the contents of the database key for a block puzzles me. Even with the help of the source code I cannot figure out it's format.

For example for the block at height 100,000, which resides under database key b\x06\xe53\xfd\x1a\xda\x869\x1f?l42\x04\xb0\xd2x\xd4\xaa\xec\x1c\x0b \xaa'\xba\x03\x00\x00\x00\x00\x00 (block's hash string converted to bytes in  little endian order), I am getting the following content which I hexlified for readability:

87c628858c201d04009be99e5883d1e92c0100000050120119172a610421a6c3011dd330d9df07b63616c2cc1f1cd00200000000006657a9252aacd5c0b2940996ecff952228c3067cc38d4885efb5a4ac4247e9f337221b4d4c86041b0f2b5710

The first 3 bytes (87c628) seem to be the same for every block that I get from the database. I'm guessing it is some version identifier?

The last 80 bytes (or 160 characters in hex) are the block header: 010000005 ... f2b5710. They match what you get by executing bitcoin-cli getblock 000000000003ba27aa200b1cecaad478d2b00432346c3f1f3986da1afd33e506 false.

The rest is a mystery to me. I know that block 100,000 had 4 transactions, but the byte that holds the value 4 has 129 for block #1, which had only a single transaction.

Where can I find out about the format of, at least, the block keys in LevelDB?

Could it be that the format of each key depends on the version of bitcoind that serialized the contents? If so, how do I figure out which format to use?


texts: signrawtransaction of a P2SH-P2WPKH spend seems to be broken?

texts:
I'm trying to spend a SegWit output on testnet using the Bitcoin core's RPC commands.
Without importing the private key into my wallet (i.e. w/o addwitnessaddress).
I wonder if anyone had luck spending SegWit outputs this way? Perhaps the signrawtransaction is broken in this case?
Here are the commands and my results.
What's weird is that even though the signrawtransaction itself is successful, the transaction is not valid (rejected by sendrawtransaction and rejected by block explorers as I'm trying to push it, as well).

(Please note: every time I import the key into the wallet and do an "addwitnessaddress" everything works just fine).

./bitcoin-cli -testnet createrawtransaction '[{"txid":"03a4ffcc792525b4ddaecc05054114f2ad8aff8b7563cd41cdb496e2177d0117","vout":0}]' '{"mwCwTceJvYV27KXBc3NJZys6CjsgsoeHmf":0.8}'

020000000117017d17e296b4cd41cd63758bff8aadf214410505ccaeddb4252579ccffa4030000000000ffffffff0100b4c404000000001976a914ac19d3fd17710e6b9a331022fe92c693fdf6659588ac00000000

./bitcoin-cli -testnet signrawtransaction 020000000117017d17e296b4cd41cd63758bff8aadf214410505ccaeddb4252579ccffa4030000000000ffffffff0100b4c404000000001976a914ac19d3fd17710e6b9a331022fe92c693fdf6659588ac00000000 '[{"txid":"03a4ffcc792525b4ddaecc05054114f2ad8aff8b7563cd41cdb496e2177d0117","vout":0,"scriptPubKey":"a91421ce1507d06ed2742be0bf18a018bbcdd812a26487","redeemScript":"00149835f2e0dff9d7f6a4060140696bc7e00b12edd5"}]' '["cMahea7zqjxryy6NWaKxmhDyb1JzuNKCZAg8sxaJoXSBkRXjnib9"]'

{
  "hex": "0200000000010117017d17e296b4cd41cd63758bff8aadf214410505ccaeddb4252579ccffa40300000000171600149835f2e0dff9d7f6a4060140696bc7e00b12edd5ffffffff0100b4c404000000001976a914ac19d3fd17710e6b9a331022fe92c693fdf6659588ac024730440220452a58cf56c45edaffb952acccd2f6f2cea523cf82e73b82f8eb5e3b3b1b17c4022011de26884cf693b12f16fdd8fa6c1d96dacb97050907353852895d9b80b3fae101210206f4bad90006f70112129815b25ba585484f1bb4f8b88f8ebaec2c76f543794300000000",
  "complete": true
}

./bitcoin-cli -testnet sendrawtransaction 0200000000010117017d17e296b4cd41cd63758bff8aadf214410505ccaeddb4252579ccffa40300000000171600149835f2e0dff9d7f6a4060140696bc7e00b12edd5ffffffff0100b4c404000000001976a914ac19d3fd17710e6b9a331022fe92c693fdf6659588ac024730440220452a58cf56c45edaffb952acccd2f6f2cea523cf82e73b82f8eb5e3b3b1b17c4022011de26884cf693b12f16fdd8fa6c1d96dacb97050907353852895d9b80b3fae101210206f4bad90006f70112129815b25ba585484f1bb4f8b88f8ebaec2c76f543794300000000

error code: -26
error message:
64: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation)


texts: is it safe to share the indexes folder between computers?

texts:
my understsanding is the indexes folder is created if you have tindex set to 1 and want to keep an index of all transactions. all of the material i've seen (bitcoin core documentation, on this site, etc) either:

says it's safe to copy only blocks + chainstate between computers
lists files + folders which are expressly unsafe to copy (ex. wallet.dat).

my understanding + intuition of the indexes folder (from docs + inspecting the files myself) is that it has no pii and should be safe to copy but i just wanted to confirm.


texts: I noticed that bfgminer is using 100% CPU on my Linux system even though it's using a Block Erupter ASIC.  Why is it using so much CPU? Is it possible to prevent that?


texts: If you trade with bitcoins, how do you manage to "explain" anti-laundering authorities the money-in & money-out?

texts:
When trading with bitcoins using mtgox, or bitcoin-24, or bitcoin.de, you will have in your account many transfers of money, to many people and from many people. In europe if the sum of the transactions is more than 10.000 €, your bank should send a notice to anty-laundering authorities.

How do you manage it?


texts: Why aren't early adopters intervening in the market in order to stabilize the BTC price?

texts:
They have every motivation to do so.

Extreme volatility is bad for confidence and can hurt the chance of Bitcoin becoming a respected currency.

Say for the sake of argument that Satoshi owns 500,000 BTC. This is a conservative estimate.

Someone holding that much BTC could easily dampen the wild price swings we are seeing at the moment by selling large quantities when the price spikes and buying them back when it crashes.

By doing this they risk losing a fraction of their bitcoins.  However, this would also increase the probability of bitcoin’s success and them becoming multimillionaires.

Which would you choose?

50% chance that you own 500,000 BTC worth $500 Million USD in 2017. 50% chance that bitcoin fails to take off and they are worth $5 Million USD.
80% chance that you own 300,000 BTC worth $300 Million USD in 2017. 20% chance that bitcoin fails to take off and they are worth $3 Million USD. Plus $16 Million USD profit right now.

Note: The above numbers are not meant to be scientific. They are just simplifications meant to illustrate the gist of my argument.

I don’t see how any rational person would choose option (1), unless they have some really crazy lopsided utility function for money.

So why isn’t it happening? Why are most coins mined in 2009 practically untouched?


texts: ZeroMQ support in Bitcoin Core 0.16.0 out-of-the-box?

texts:
In my previous question, I'm wondering why Lightning Networks lnd cannot talk to my Bitcoin Core bitcoind backend.

The docs for lnd says it requires ZeroMQ compiled into bitcoind.  Does the binary version of Bitcoin Core bitcoind 0.16.0 contain ZeroMQ?


texts: Are decentralized currencies absolutely critical

texts:
If Ripple is not really decentralized and yet obviously effective, quickly adapted to use and successful, should it matter?  Does it not give more certainty and security in use especially with new currencies and ICO's set to launch?  I am quite new to the Cypto space and eyeing a potential ICO - Laxmicoin, which is working with the Reserve Bank of India pre-launch.  Is there any reason that receiving the RBI's approval and interaction would be detrimental to it's long or short term success?  India, being the World's largest democracy and most of the population outside of any possible banking facility, lends itself to immediate and enormous potential for cryptocurrency.

Please advise...


texts: does anyone know how to send the "exp" parameter in an Electrum request

texts:
I tried modifying the request so it would include a 3600 second expire time. (minutes - 1 hour) as shown in the example  it returned an error the parameter was invalid.  It shows - but as "null"

curl --data-binary '{"id":"curltext","method":"addrequest","params":{"amount":"3.14","exp":"3600","memo":"test"}}' http://127.0.0.1:7777

{"error": {"message": "Invalid parameters.", "code": -32602}, "jsonrpc": "2.0", "id": "curltext"}[

This is Electrum client daemon - not server - Linux (CentOS 7) - not Windows - it runs and returns a request fine without the "exp" parameter


texts:
I'm a novice to bitcoin trying to learn mining. I know that in order to get the value (header) to hash, you call Getwork. I have seen the bitcoin wiki page for it and read some relevant threads on different forums. What I want want to know is what is required before one can make a call to Getwork? Specifically the following:

What URL to call with what parameters?
I understand it is a REST call. Can you confirm this is so?
Do you need to be registered before being able to make the call?

Please post any relevant links that might help.


texts: How is the bitcoin price affecting other crypto currencies

texts:
I am still pretty new to the crypto world, and especially to the world of finance.
When thinking about buying some alt coins I realized that this is in most cases only possible via Bitcoin.

My questions:

Isn't the current price of Bitcoin and it's volatility directly influencing/affecting all alt coins that can only be bought via Bitcoin?

How are the prices of alt coins calculated to not show this dependency?

This is a very broad question I guess. Appreciate any help!


texts: I have an ASIC Jalapeño Bitcoin Miner. It mines consistently at around 5000 GH/s. I have been mining using the BitMinter Miner and BitMinter Pool just because it is easy to setup and get running quickly and that's what I wanted to do upon receiving my Jalapeño. However, I now wish to maximize my mining profits. I have read lots about mining etc and I have seen a lot about multi mining. I found a pool called MultiPool and made an account. However, I am unsure how to get mining on the pool now. I have an iMac that I will be running the Jalapeño from. I want a simple, stable, and reliable mining program. But all my attempts to download CGMiner for Mac have failed. How can I get mining on Multipool with my Jalapeño?


texts:
I've just attempted to send some bitcoin between 2 wallets and the amount received in the receiving wallet doesn't match the input, can someone explain why?

Here is the transaction https://blockchain.info/tx/53d1083c08eacf36629f544d19546199029a6fc461215a73a07c7c4adb01a7c2

The input was 0.0032 BTC, the fees were 0.00050278 so I expected to see 0.00269722 hit the receiving wallet. What looks to have happened though is the output was split and I actually received 0.00069722 BTC and the 0.002 BTC has gone to a wallet that I don't recognise.

Can someone shed some light on what's happened? Why the 2 outputs? Looking at my previous transactions it's always been a 1:1 input/output relationship.

I know it's only small amounts but keen to understand whats happened and where I can retrieve that 0.002 BTC.

Cheers


texts: How Do Peers Choose Which Peer To Trust?

texts:
So the way I understand how the blockchain works is that each new block uses the previous block's hash, which means if my block[100].hash != someone_elses_block[100].hash that means that either I broke some rule, or the other person did; In this case, how does my client find a trusted peer? And WHERE does my client get the latest CORRECT blockchain? Is there a central server for it? If so, where did the server it from? Because the miner will have the longest chain, but what if they are not actually following the rules? Then what?
Lets say I stopped my client for 100 days, during those 100 days there was 500 new transactions, which means that if I was to compare my last block with someone elses then my client would be outdated, therefore it needs to download the extra blocks, where does it find these blocks and how does it determine which peers to sync to and to trust?
A question about the nonce, if lets say there was no nonce; If client A has a chain that followed the rules and client B was verifying transactions without actually doing all the proper checks, that means that client A at block[100].hash != client B at block[100] therefore client B is not following the rules, so the question is what is the real need for the nonce? Because in my mind it seems like it's just there to make it harder to mine for people, correct? Or does it add some sort of security? And if it does, will it have the same security if let's say the nonce was always any number between 0 and 15? Or would it have to be adjusted as mining gets faster?

Thanks!


texts: Apart from its main purpose, what is bitcoin network used for?

texts:
In the Ethereum Homestead docs there is a paragraph

  But as bitcoin began attracting greater attention from developers and technologists, novel projects began to use the bitcoin network for purposes other than transfers of value tokens. Many of these took the form of “alt coins” - separate blockchains with cryptocurrencies of their own which improved on the original bitcoin protocol to add new features or capabilities.

Questions are:
1. What are the best examples of such 'other purposes' and projects, especially the ones that are not altcoins?
2. What are the most prominent altcoins that haven't lost their significance?


texts: Bitcoin Wallet is downloaded I think. What next?

texts:
Please excuse me if I use the wrong vocab - as I am unfamiliar with this and so will probably explain myself like a foot.
Here goes. I am on a Mac and I think I have downloaded the block chain and I now have a window called Bitcoin - Wallet showing Balance: 0.00 BTC and Unconfirmed: 0.00 BTC and Number of transactions: 0.

Now what?
1) I thought I should be getting an address or something that I need to copy and keep safe - and
2) I should create a Password.

I don't want to close the Bitcoin-Wallet window in case I make it disappear for ever ..
3) Should I be getting a little picture of a wallet on my desktop?

Thank you


texts: Bitcoins never showed up in wallet. Yet sender says transfer complete

texts:
I've used a site called bit trade australia to buy and send bitcoins to a wallet on blockchain.info. Successfully three times this month, trusted too.

Yet this time (after receiving an email from BTA, "your coins have been transferred" like normal) there is zero proof on blockchain.info of this happening. My wallet hasn't changed. No bitcoins. It's been 13 hours since that email. And I assure you, this has never happend to me before.

Any ideas? Thank you, Regards.


texts: Which is the smallest hash that has ever been hashed?

texts:
Let's assume, the hash 00000000000000000024c0bdbec66a889778c00bc69be0a96cbbd98b75c3ce09 of block #499644 is smaller than
0000000000000000002d429f39afec70c938e888c3417d690bbc85e83529991c of block #499645.

They both have 18 Zeros, then 2=2, but then 4<d.

Which is the smallest hash that has ever been hashed during cryptomining? How many zeros? Which block?


texts: How to set the sequence number in a coinbase transaction?

texts:
The sequence number seems to be used for locking a transaction in mempool. However, the coinbase transaction is not part of the mempool and thus the sequence number does not make sense.
Is it just an "extra nonce"? Or is there any constraint on the sequence number in a coinbase transaction?


texts: How do I import private keys from Bitcoin-qt to Multibit client?

texts:
Question says it. I spent 20 mins Googling. Saw several links on bitcointalk.com but amazingly found no solution to this. Am I the first one trying to do this?
Note the following are not the solutions I am looking for:

Transfer the BTC from Bitcoin-qt to Multibit by making a transaction
Some commandline geeky stuff


texts:
What is the underlying mechanism?

Do you transmit a message to a local node who then relays it? How does that relay work? I know about DNS seeding but then how does the rest of the relaying occur? If every node transmitted every transaction it received then that's a lot of network use and a lot of retransmitting the same message to the same nodes.


texts: How exactly is Rucoin different than Bitcoin?

texts:
Rucoin is a "Russian Bitcoin clone" (see announcement thread).

Besides the fact the website is in Russian, what other characteristics does this coin have?

Is it just a 1-to-1 Bitcoin clone? Is mining limited to clients from Russia? This post claims that

  Rucoin provides some tools functionally similar to central bank and
  the stabilization fund, whose main task - to make the course of
  crypto-currency stable, predictable and guaranteed.

Does anyone know how they claim this is achieved ... or in other words, how exactly is Rucoin different than Bitcoin?


texts:
I recently tried playing around with the getwork command for JSON-RPC and I'm trying to understand what I got out of it. According to the API Call List wiki entry, the "data" field should contain the block data to be hashed.

The data field I got was:

00000001a10bacc7e639d1c69a01014bc5db6f2604b3477a3f273a4e019a232700000000a5942372cc60477c8a276e59c8f1a3f58654ea2f6c4402bf1b18e48455b5b8f64f10868b1c07475200000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000

Which after being dissected a bit according to the protocol would yield:

00000001 - version
a10bacc7e639d1c69a01014bc5db6f2604b3477a3f273a4e019a232700000000 - prev_block
a5942372cc60477c8a276e59c8f1a3f58654ea2f6c4402bf1b18e48455b5b8f6 - merkle_root
4f10868b - timestamp
1c074752 - bits
00000000 - nonce
00 - txn_count of 0?
0000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000 - ??

Is there something wrong with the data I'm getting? Would the client respond differently if I run it with the -gen option?


texts: Is this Merkle hash root problem existent in Bitcoin?

texts:
In the Wikipedia article about Merkle trees, I was just reading this, unable to  understand where the problem lies:

Second preimage attack
The Merkle hash root does not indicate the tree depth, enabling a second-preimage attack in which an attacker creates a document other than the original that has the same Merkle hash root. For the example above, an attacker can create a new document containing two data blocks, where the first is hash 0-0 + hash 0-1, and the second is hash 1-0 + hash 1-1.
One simple fix is defined in Certificate Transparency: when computing leaf node hashes, a 0x00 byte is prepended to the hash data, while 0x01 is prepended when computing internal node hashes. Limiting the hash tree size is a prerequisite of some formal security proofs, and helps in making some proofs tighter. Some implementations limit the tree depth using hash tree depth prefixes before hashes, so any extracted hash chain is defined to be valid only if the prefix decreases at each step and is still positive when the leaf is reached.

My first questions are: Is this really a problem in Bitcoin? If yes, how is it being solved in Bitcoin core?
My second questions are: Could this problem be solved by storing the tree depth of each block directly in the block chain? Or speaking of Bitcoin, would that negatively affect the block validation procedure itself somehow?


texts: unable to get transactions in wallet console

texts:
I'm trying to get transactions infos out of the bitcoin core wallet with the console.
For that I picked a random transaction of a block from today and tried to access it with

  gettransaction 8c0430d0139603db9983daf539604c612b3f7e8d5244aefc3cd3181ece08dd1f

Instead of a json-output with the decoded transaction I get

  Invalid or non-wallet transaction id (code -5)

Shouldn't I be able to retrieve every transaction in the blockchain with this command?

How can I read/access the transactions included in mined blocks?
I already did this on some altcoins with PoS and there is was possible for every transaction. Now with bitcoin it seems that only wallet transactions are available? Why is that and can I get around that to access / read the transactions on my own?

The same problem appears to be with the getrawtransaction command, so I can even decode a transaction on my own.

I run a bitcoin core 0.14.2 and my blockchain is up-to-date.


texts: Trying to create a bitcoin public/private key using bitcoin-core

texts:
I want to create a single bitcoin address to which I can send and receive funds too.  Using the bitcoin-core console, I typed in the following:

Input:
    getnewaddress

Output:
    Address: mhYC9ybAa2aHivEjYzyp7WcMXtpcmJvgV2

Input:
    validateaddress mhYC9ybAa2aHivEjYzyp7WcMXtpcmJvgV2

Output:
    Public Key: 02b33243d76c40e310a4214d8459f59d569f19f5804a26f0e1d70cf28d605411b3

Input:
    dumpprivkey mhYC9ybAa2aHivEjYzyp7WcMXtpcmJvgV2

Output:
    Private Key: cRYUqjikPgyVsWGfL26Q2i26vAAizgurajhW8mBZf2mRCM9NKf5W

Questions:

Are those 3 values all I need to save to ensure I can easily send and receive funds?
To receive funds, do I need to use the [Address] or the [Public Key] value?
The [Public Key] seems to be a hex value, and the Private Key seems to be a hash value, is it possible to extract the hex value of the [Private Key] using bitcoin-core console?

Note:

The above values were created on the testnet.
I understand that technically I only need to save the [Private Key] and can generate the [Public Key] from the [Private Key]
I understand that I will have to specify a change address so I don't lose any balance if I do not spend the total amount.


texts: Does bitcoin.conf expand environment variables?

texts:
I would like to store my Bitcoin RPC passwords and usernames in environment variables, like:

rpcuser=$RPC_USER
rpcpassword=$RPC_PASSWORD

Is this supported in bitcoin core? Can environmental variables be parsed from my bitcoin.conf file?


texts: Unconfirmed transaction: does the receiver know about it?

texts: I just sent someone some bitcoins, but it's still at the unconfirmed transaction stage.  But does the receiver know this information yet, i.e., that I have sent and we are merely waiting for it to go through?


texts: Do miners have an incentive to confirm various transactions from same address?

texts:
Mempool is really clogged those days. I tried to make a transaction from one of my address to a friend. As we didn't care about confirmation time, I put a 5 sats/bit fee.
2 weeks later, transaction still wasn't confirmed. But, from same address, I had to send another transaction of all remaining funds on the address. I was in a hurry so I put next-block estimate fee.
My second transaction has been confirmed as planned in next block but, interestingly, my first transaction was also confirmed in that block, even if mempool was still clogged.
I want to understand what was the incentive for the miner to confirm my first transaction, and if I can use this mecanism.  For example, if I have to send 2 transactions with confirmation in next block, can I be confident to put high fees in only one of them?


texts:
Way too complex. Give me an actual example as to how this works? For example;

How do I purchase bitcoins?
How much do they cost; is there an exchange rate?
How do I redeem them; turn them back into dollars?


texts: I'm wondering if I can manage my bitcoins with my other securities? Or incorporate them into a business plan.


texts: listtransactions via RPC returns false in PHP

texts:
In PHP I run

$bitcoin->listtransactions("count = 5, offset = 0");

In the hope of getting 5 transactions only, but I get the response

bool(false)

When I run $bitcoin->listtransactions(); alone, it works fine.

What am I doing wrong?


texts: How to know that the account balance of a user needs to be updated after paying/sending an invoice?

texts:
Lets say there is a service in which users can have a few satoshis but are also able to deposite/withdraw satoshis by paying/sending a lightning invoice. Let us assume the service has some data store which tracks the account balance for the user:

What is the best practice architecture to know that the account balance needs to be updated?

I know there is the waitinvoice RPC-call in c-lightning which tracks the label of an invoice (which could be a user id + some other data). Still in a live application the site should update the balance once the invoice was paid. If however the user left the side and pays the invoice it still needs to work so there needs to be some bridge from the lightning node to the data store.

In withdrawing the situation gets even more critical since withdrawing can take some time and calls can occure concurrently balance needs to be locked or widthdraw calls have to by synchronized (which I guess ist not preferable)

So what kind of architectures / best practices are you using?


texts: Using bitcoin-core RFCs to create REST APIs

texts:
I am new to using Bitcoin and the Lightning Network.

I was looking at this: https://bitcoin.org/en/developer-reference#bitcoin-core-apis  I saw REST APIs as well but did not seen any functions for POST, DELTE, etc. Would be realistic to try to make a REST APIs using these functions. One should not have to worry about authorization since the Blockchain is public - right? I wanted to create functionality that would be called when openning/closing a Channel on the Blockchain from the Lightning Network.

Also, I was hoping that in creating a BTCD daemon (and synching it with the Blockchain), one could perhaps have their transactions commit faster. But, it looks as though this can only be done by miners(?) Is my understanding correct?

TIA


texts: Can I save stuck bitcoins by creating a completely new transaction?

texts:
I tried to make a bitcoin payment but accidently set a too low transaction fee so it got stuck. By now the payment is cancelled so I don't want to do this transaction anymore.

Can I now instruct my bitcoin adress to send the bitcoins somewhere else (instead of the stuck transaction) by broadcasting a completely new transaction? I used Bitcoin Core for the initial transaction.

P.S. Nobodys waiting anymore for the initial paymant so I'm not trying to scam anyone here.


texts: How do you configure windows to store the bitcoin blockchain data into another directory?

texts:
I'm currently on windows and was wondering how do you make the qt client download the blockchain data to another directory? Since my main drive is a SSD hard drive, I don't have much space to spare. How would I configure this to make it download elsewhere?

Also would this apply to other qt clients like litecoin, ppcoin, etc?


texts: Alternative: Mining scheme driven by logistic function

texts:
Could a mining scheme driven by logistic function bring a greater price (= exchange rate) stability to a crypto-currency in comparison to Bitcoin for example since it better models natural growth?

Simply the monetary base would grow according to this function. This would mean that till half of the scheme period block rewards would rise from 0 coins to X coins and in the second half fall from X to 0. After the scheme's period would be over and all currency had been mined, transaction fees could be introduced to keep the system working.

Picture: Chart of logistic function (credits: https://en.wikipedia.org/wiki/File:Logistic-curve.svg)


texts: java.lang.NoClassDefFoundError: org/spongycastle/util/encoders/Hex in Java when dealing with Bitcoin addresses

texts:
I have a private key bigInt of type bigInteger and I would like to generate the address corresponding to this private key. I implemented the following function

public String get_address () {
Address address = new Address(NetworkParameters.prodNet(), Utils.sha256hash160(new ECKey(bigInt).getPubKey()));
return address.toString();
}

When compiling, I have

Exception in thread "main" java.lang.NoClassDefFoundError: org/spongycastle/util/encoders/Hex
at com.google.bitcoin.core.NetworkParameters.<clinit>(NetworkParameters.java:49)
at bitcoin.get_address(bitcoin.java:40)
at main.main(main.java:11)
Caused by: java.lang.ClassNotFoundException: org.spongycastle.util.encoders.Hex
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 3 more

I guess that I need to import the library org.spongycastle but I don't know how to do that in Eclipse.

Who can help me with this?

Thanks a lot.


texts: How to generate a new extended public key (xpub)?

texts:
I have a need to generate a new extended public key (xpub).

Examples:

xpub6CUGRUonZSQ4TWtTMmzXdrXDtypWKiKrhko4egpiMZbpiaQL2jkwSB1icqYh2cfDfVxdx4df189oLKnC5fSwqPfgyP3hooxujYzAu3fDVmz

tpubD6NzVbkrYhZ4WLczPJWReQycCJdd6YVWXubbVUFnJ5KgU5MDQrD998ZJLNGbhd2pq7ZtDiPYTfJ7iBenLVQpYgSQqPjUsQeJXH8VQ8xA67D

How can I do this?

I would like to do it inside json rpc, because that would help automate testing, but I ultimately don't care how I get them. They are for testing.


texts: Is there a light (SPV) version of bitcoin core (bitcoind)?

texts:
I'm trying to develop an SPV Bitcoin client which makes use of a library requiring bitcoin core (a running bitcoind service).
However, from what I understand, Bitcoin Core is full node, meaning that it stores the whole blockchain.

My question is: there exists a service which is similar to bitcoind (that is it provides a JSON-RPC server), without needing the whole blockchain?


texts: bitcoin-cli "getbalance" always returns 0

texts:
I have bitcoind running on windows and currently it's syncing the blockchain. Nevertheless, command getbalance always returns zero as value. Even if I seach for an address which has bitcoin.

E.g.
C:\Program Files\Bitcoin\daemon>bitcoin-cli.exe getbalance "[address...]"
0.00000000

Why does it always return 0? I would like to get the address balance of a specific address. I used an address from blockchain.info which had a balance before the current downloaded block.


texts: what happens if i sent bitcoin to a clubcoin address (address starts with a C)? will i get refunded and get notified the transaction was invalid? please help me!


texts: is the proof-of-work for safety or efficiency?

texts:
i am reading the proof-of-work (aka: pow, target threshold, difficulty, etc.); my understanding is that pow adds a requirement to validate block headers, so that both benign and malign nodes need a reasonable amount of time to create a valid block; but i dont see how this rate limit relates to safety; even if there is no pow, so that every block is valid, as long as benign nodes have the majority of computing power, couldnt they still guarantee the main chain is correctly formed?

for example, assuming benign nodes are the majority:

with pow, malign nodes generate new blocks at m blks/min, while benign nodes at b blks/min, and b > m;
without pow, malign nodes generate at 100000m blks/min, while benign nodes at 100000b blks/min; we still have 100000b > 100000m (even though the public ledger now grows much larger);

above is an extreme example, but you could imagine adjusting pow step by step, from current 10 blks/min to 20 blks/min, to 30blks/min, etc. does the bitcoin protocol become less secure from the adjustments?


texts: libudev error while configuring cgminer on fedora 22

texts:
I am using Fedora 22, 32bit OS and have Antminer U3 for mining operations

got the cgminer source code from GIT:
git clone https://github.com/bitmaintech/cgminer

while running ./configure --enable-icarus the command ends up in error as below

./configure: line 11972: -pthread: command not found
checking libudev.h usability... no
checking libudev.h presence... no
checking for libudev.h... no
configure: error: "udev support requested but libudev not installed"
configure: error: ./configure failed for compat/libusb-1.0

I tried using system libusb, but no success

./configure --enable-icarus --with-system-libusb

checking for pthread_create in -lpthread... yes
checking for library containing addstr... no
configure: WARNING: Could not find curses library - if you want a TUI, install libncurses-dev or pdcurses-dev
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for LIBUSB... no
configure: error: Could not find usb library - please install libusb-1.0

libusb is part of systemd package and my system has latest installed.
checked from

sudo dnf upgrade systemd

command returned Nothing to do.

Could you please help where i could be going wrong in setting up CGMiner ?

PS: I tried bfgminer, but ended up in errors.


texts:
I have read a lot of documentation and books where they explain the general functioning of Bitcoin and I think that the time has come to study the source code of Bitcoin core.
I have knowledge of c++ and python but due to the large size of the project and the number of files, I don't know where it would be correct to start.
Could someone help me on how to properly perform that task?


texts: Positive or negative private key of a bitcoin wallet?

texts:
Private key is a number. Is the question positive or negative? Is it possible to know a positive private key or negative if you only know the public key?

For instance:

Positive private key: 2

public key:

04C6047F9441ED7D6D3045406E95C07CD85C778E4B8CEF3CA7ABAC09B95C709EE51AE168FEA63DC339A3C58419466CEAEEF7F632653266D0E1236431A950CFE52A

Negative Private Key:
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD036413F

public key:

04C6047F9441ED7D6D3045406E95C07CD85C778E4B8CEF3CA7ABAC09B95C709EE5E51E970159C23CC65C3A7BE6B99315110809CD9ACD992F1EDC9BCE55AF301705

Now I will write two public keys to "3" and "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD036413E":

04F9308A019258C31049344F85F89D5229B531C845836F99B08601F113BCE036F9388F7B0F632DE8140FE337E62A37F3566500A99934C2231B6CB9FD7584B8E672

04F9308A019258C31049344F85F89D5229B531C845836F99B08601F113BCE036F9C77084F09CD217EBF01CC819D5C80CA99AFF5666CB3DDCE4934602897B4715BD

How to determine which is a positive and which is a negative private key to these two public keys?


texts: Where can I find the structure and layout of what exactly gets hashed by miners?

texts:
I understand that a miner has a list of bitcoin transactions since the last time a a block was discovered. The first entry is the reward for who discovered the previous block. As more transactions gets added, they're appended to this list. This part is speculation, but I think there's also a nonce that the miners inject in order to produce a hash output that meets the difficulty.

Where can I find out the specifics about what exactly is hashed? I'm looking to understand the exact bytes and structure.


texts:
Bitcoin is slowly synchronising

  Synchronising the  network... 78 weeks behind

Do all weeks of blocks take the same time to process? Or will recent blocks be slower because Bitcoin is more popular now?

It felt like going from '100 weeks behind' to '80 weeks behind' took longer than going from '200 weeks behind' to '100 weeks behind'


texts: Is it theoretically possible to have an inverted nLockTime?

texts:
For example, an nLockTime == 500 prevents a transaction from being included in any blocks before the block 500.
Why isn't there a parameter like nExpireTime == 500 that prevented a transaction from being included in any block over the 500? Would it be theoretically possible to have one or it's a flawed approach for some reason?


texts:
I'm thinking about running a bitcoind full node to help out the bitcoin network.

Would it be feasible to run a full node through one of the new macbooks?

(12", 250GB HD, 8GB RAM, 1.1 GHz Intel Core M processor)

thanks!


texts: Undo files format change and reorg process question for v0.19

texts:
This is a follow-up question for rev.dat file format

Pieter Wuille gave a great explanation that is easy to follow. Since that posting there was a replacement of CTxInUndo with Coin, does the format still stands for the CBlockUndo record?

4 bytes: network magic (0xf9,0xbe,0xb4,0xd9)
4 bytes: size of the CBlockUndo record (LE32)
data_size bytes: CBlockUndo record
32 bytes: double-SHA256 of the serialized CBlockUndo record

CBlockUndo results in a serialized vector of CTxUndo records. Which is right now the serialized vector of Coin records.

And here is the Coin (or at least how I get it right now):

varint that is serialized: 2*height (+1 if it was a coinbase output): the height of the block that created the spent UTXO. By the way, is uint32_t{2} the same as (uint32_t)2 in TxInUndoFormatter varint Serialize
version dummy value 0: we do not use version anymore but for compatibility using a 0000 or zero value in here
CompressedAmount: spent UTXO's nValue
CompressedScript: spent UTXO's scriptPubKey

Questions:

Is it correct?
Does anyone by any chance have a detailed mind map of undo process and a byte format map for the CBlockUndo record?

Just for reference, I draw some image of current v0.19  and previous v0.13 versions
of rev*.dat file:


texts: How is the exchange rate for Bitcoin established?

texts: I noticed that there are exchange rates for Bitcoin to other given currencies. How are these rates established?


texts:
I have some questions about bitcoin-core and lightning-network-daemon.
I have succesfully set up a bitcoin node running on Ubuntu Server 20.04 by following this tutorial: https://bitcoin.org/en/full-node.
This is my node: https://bitnodes.io/nodes/81.166.125.218-8333/
I am planning on installing lnd using bitcoind as the backend, by following this tutorial: https://github.com/lightningnetwork/lnd/blob/master/docs/INSTALL.md
In this regard, I have the following questions:

What is the relationship between my bitcoin-core wallet and the lnd wallet?
What fee should I set to make my lnd node as profitable as possible?
What other recommendations can you give to help out a bitcoin- and lnd-noob like me?

Thanks in advance for all answers!
Best regards


texts:
When I try to add devices to BFGMiner and BitMinter, Only 3/4 devices will be detected, When I go to Devices and Printers (In Windows 7) it shows all of my ASIC Miners.

Here is the error:

2014.02.26 [19:09] BitMinter Client v1.4.3 started
2014.02.26 [19:09] Found 1 OpenCL-compatible GPU
2014.02.26 [19:09]  Hint: Use performance mode for best GPU results (bottom right button)
 2014.02.26 [19:09] Probing all ports for external devices
2014.02.26 [19:09]  Probe of port COM16 failed: timeout
2014.02.26 [19:09] No external devices detected.
2014.02.26 [19:09] Device detected on COM15: Icarus
2014.02.26 [19:09]  Icarus detection on COM3 failed. Expected nonce 0x00000109 but got 0x3F3F3F09.
2014.02.26 [19:09] Device detected on COM3: Icarus
2014.02.26 [19:10]  Icarus detection on COM17 failed. Expected nonce 0x00000109 but got 0xFFFFFFFF.
2014.02.26 [19:10]  Icarus detection on COM17 failed. Expected nonce 0x00000109 but got 0xFFFFFFFF.
2014.02.26 [19:10]  Probe of port COM17 failed: timeout
2014.02.26 [19:10]  Error reading from COM17: File descriptor is -1 < 0, maybe closed by previous error condition
2014.02.26 [19:10] Device detected on COM16: Icarus

How can I get the miners to detect all the devices. The devices are on COM 3, 17, 19, and 20

Thanks,
Bgordy


texts:
Say there is a soft-fork. A is the chain that implements it, B is the chain that has a transaction that's valid pre-soft-fork, but invalid post-soft-fork, so it's following the old rules. We know that A and B can merge if A gets longer since all of A's tx's are compatible with B's, but not vice-versa.

Anyway, in this situation, it's very possible that users are subject to replay attacks. If you spend on A, the same tx can be replayed on B. In order to prevent this scenario, there surely would have to be some sort of replay attack prevention.

My question: Is a replay-attack-proof soft fork possible? If so, what would be the mechanism to do it from a technical perspective?


texts: How do you generate a receive address from a string?

texts:
I already have a an address with Bitcoin and would like to generate a receive address using SHA256 hash which is based on a string.

I've found an example of creating an address using a SHA256 hash:

https://github.com/bitcoinjs/bitcoinjs-lib/blob/master/test/integration/addresses.js#L19

But I haven't found one to create a receive address from a base address using the same method.


texts: Pguc coin transfer to address of bitcoin by mistake

texts: I have an account registered with PGUC. In the spend wallet they ask for the exchange address where to transfer the coins. What happened I need to transfer these coins in Pguc address but by mistake I send to Bitcoin address. My coins disappear from the wallet. Can I recover that coin ?


texts:
I am not able to get JSON-RPC response via curl. It seems like is not accepting requests.

My bitcoin.conf

rpcuser=USER
rpcpassword=PASS
server=1
rpcport=9332

Running daemon

$ bitcoind -conf=~/.bitcoin/bitcoin.conf -daemon
Bitcoin server starting

Checking cli

$ bitcoin-cli -conf=~/.bitcoin/bitcoin.conf getinfo
{
  "version": 140200,
  "protocolversion": 70015,
  "walletversion": 130000,
  "balance": 0.00000000,
  "blocks": 439348,
  "timeoffset": 0,
  "connections": 8,
  "proxy": "",
  "difficulty": 254620187304.0614,
  "testnet": false,
  "keypoololdest": 1500029964,
  "keypoolsize": 100,
  "paytxfee": 0.00000000,
  "relayfee": 0.00001000,
  "errors": ""
}

Testing curl

$ curl http://localhost:3333
curl: (7) Failed to connect to localhost port 3333: Connection refused

Of course, the port is wrong:

$ curl http://localhost:9332
JSONRPC server handles only POST requests

Making a post

$ curl http://localhost:8332 -H 'content-type:text/plain;' --data-binary ''

The output is always empty, doesn't matter if I add data or user,password. Is always empty:

$ curl http://localhost:9332 -H 'content-type:text/plain;' --data-binary ''
$ curl http://localhost:9332 -H 'content-type:text/plain;' --data-binary ''
$ curl http://USER:PASS@localhost:9332 -H 'content-type:text/plain;' --data-binary ''
$ curl http://USER:PASS@localhost:9332 -H 'content-type:text/plain;' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"getinfo","params":[]}'
$ curl --user USER:PASS http://localhost:9332 -H 'content-type:text/plain;' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"getinfo","params":[]}'

Any ideas why is this happening? Don't know what else to try.


texts: If I live in the USA, and buy/sell bitcoins from a Japanese exchange, are their any advantages/disadvantages for doing this, instead of buying bitcoins from a USA exchange?


texts:
I am new to bitcoin mining.

i have gui-miner, setup a slash mining account, and i have a VM Ware machine setup for mining.

i have my own reasons for using a VM Machine and not my own...

now whenever i open guiminer and click on start mining(given all valid fields and having setup mining worker as well), the miner says that nothing to mine on, exiting.

i do not have any OpenCL or any graphics card as it is a VM Machine.

can anyone help me on this...


texts: Does the main miner software used currently use HTTP JSON-RPC, or JSON-RPC? That is, do they use HTTP calls to obtain getwork, or TCP/IP?


texts: Why is Bitcoin Core using LevelDB instead of Redis or SQLite?

texts: Why did Core move from BDB to LevelDB? Why don't they use SQLite or move to Redis now? Is there a technical reason for this choice?


texts: How can I protect my funds in the event a quantum computer breaks the ECDLP that Bitcoin relies on?

texts:
An interesting question was posted recently, discussing the idea of hashed addresses being (not meaningfully) quantum resistant.

As Andrew's answer on that question points out, paying to a hashed address does not 'quantum-proof' your coins, however there is a mention of using a zero-knowledge proof of a BIP32 seed to recover coins safely, against the threat of a quantum computer capable of breaking the elliptic curve discrete logarithm problem (ECDLP).

If this is possible, then clearly there are advantages to more complex constructions for addresses (the BIP32 key-derivation function being apparently more quantum-proof, in this case).

So my question is: what address constructions are known to provide some level of safety from a quantum computer defeating the ECDLP? How is this safety provided? How can a user create addresses today, to allow themselves the best chance of having their Bitcoin-wealth survive a highly capable quantum computer?

Note that this question is meant to explore what a user can do now to mitigate the risk of the 'worst-case-scenario' of ECDLP being broken suddenly and unexpectedly soon; with time to plan there are obviously less scary ways to switch to a quantum-secure algorithm.

EDIT: for the sake of this question, lets assume that users have unanimously agreed to fork the chain from a certain block that was mined before the quantum-computer attack began, and the fork will lock all coins that are easily stolen by the QC (P2PK outputs, reused addresses, etc). Consider the case in which every bitcoin is stored at an address which will allow safe recovery, suddenly the potential damage to the network is lessened greatly. Even if this is unlikely, I think it is academically interesting.


texts: Send and Receive BTC with Same Address from 1 Person

texts:
Is it possible to :
I sent BTC to A from Address1 and I asked him to send me BTC (different amount as I send him) to Address1 (same address with I sent him before)..?


texts: This answer seems simple, but I'm finding mixed answers. This question describes the conversion from little-endian to big-endian hex strings (or vice-versa) as switching the order of bytes in every slice of four bytes, where here it's described as just a string reversal. Both seem correct in their contexts, so what's really going on?


texts: If someone with a business account wants to send me bitcoin, do I need a minimum deposit in my wallet?

texts: If they have a business account with a high amount in it, do I need a minimum of £550 in mine for them to be able to transfer?


texts:
I have this Bip44 path implemented

m / purpose' / coin_type' / account' / change / address_index

Is it possible to use the Master private key to sign all the tx
ie. Bitcoin TX, Etherum TX

or do I have to get the asset based private keys for each asset and sign the tx's ?


texts: How can I specify multiple txids in createrawtransaction function?

texts:
I saw we can specify multiple txids, but I've never seen such a case.
So I wanna make it sure.
Thanks


texts: Has anyone used Bitstamp international bank transfer?

texts:
I want to use bitstamp to sell my bitcoins and receive USD in my bank account in Pakistan through wire transfer. Has anyone used this service at bitstamp? How long does it normally take and did you experience any hurdles in the process?
Also are there any alternative services like bitstamp which are reliable, offer good conversion rates and low fees for international transfer?


texts: Error validating transaction using BLOCKCYPHER

texts:
I recently followed the steps on the answer by StephenM347 to the following problem:

Cannot access my bitcoins because my wallet is still synchronising. What can I do to spend them immediately?

However, on the last step (broadcasting my transaction on https://live.blockcypher.com/btc-testnet/pushtx/) I got the error message:

Error validating transaction: Transaction eddxxxxxxxxxxxxxxxxx orphaned, missing reference 00350a8xxxxxxxxxxxxxx.

I am very new to this and all I want is to have my bitcoins on a MultiBit wallet (where I sent the Bitcoin Core bitcoins to).
Could anyone point me in the right direction here?


texts:
I was looking at some sample mining algorithms and also some sample code and there was something which I didnt really understand. In Simple bitcoin mining algorithm he says ,
The simplest miner would work like this:

The simplest miner would work like this:

     1. Request a new [Getwork][1] from a given pool/bitcoind with specified credentials
     2. For nonce=0;nonce<0xFFFFFFFF;nonce++
     - Set Getwork Data nonce
     - SHA-256 hash the Getwork Data ([block header][2])
     - Check if hash result is smaller than Getwork Target, if so, submit a share
     - If more than 1 second passed since you received Getwork, stop the loop
     3. GOTO: 1

What I dont understand is step 2, part 4. Lets consider the above script is connected to an FPGA through a uart port. Wont I wait until the FPGA actually finds a valid nonce and submits the none through the UART line? Why would I exit out of the loop after 1 second and then go through the entire process again. This doesnt make sense to me because then the fpga has only a few seconds to increment the nonce for the given work and it then moves on to the next piece of work? How is this even realistic since even if the same work is submitted again it will go through the same loop and will end up doing nothing productive. What error am I making here? Sample code that I am talking about:

https://github.com/progranism/Open-Source-FPGA-Bitcoin-Miner/blob/master/projects/Verilog_Xilinx_Port/sources/software/miner.py does the same thing. It says golden.wait(timeout) instead of just calling golden.wait() and blocking till a nonce is found


texts: What is the cost of setting up a bitcoin account

texts: does it 'cost' anything to set up an account? If bitcoins are virtual, why/how does an exchange rate work?


texts: Are there any good websites to recommend? thank you

texts: Knowledge about Bitcoin, as a beginner, what to learn. Is there a good website to recommend? About bitcoin.


texts:
Before I get started I would like to say I am an advocate of a virtual, peer to peer currency and bitcoins to an extent. I think some of the worst aspects of capitalism as well as huge amounts of power have manifested themselves in the finance sector and it would take something as radical as bitcoin to take the power back.

I am interested in why anonymity is important in bitcoins. Some of the other "worst aspects of capitalism" are the tax dodging multinationals that lie and cheat and as a result prevent the fair distribution of wealth amongst the population. Surely if bitcoin was adopted widely as a currency this would only worsen matters as there could be no means of taxation and thus projects like public health, education and law would break down.

What is the problem with making transactions traceable. Would this not make a virtual peer to peer currency more likely to succeed?


texts: What's stopping an infinite number of altcoins with the same protocol from appearing in the future?

texts:
My novice understanding of BTC is that BTC is valuable because it's scarce - mathematically, there can only be 21M BTC, no more.

What's stopping another altcoins from starting with the same protocol, but a new chain, rendering the limit of BTC to N * 21MBTC?


texts:
I am new to Bitcoin Development Environment. Trying to setup testnet environment with the help this blog post.

Bitcoin Folder
~/.bitcoin $ ls
bitcoin.conf  chainstate  db.log     peers.dat
blocks        database    debug.log  wallet.dat

bitcoin.conf

telnet=1
server=1
rpcuser=userme
rpcpassword=mypassword
rpctimeout=30
rpcport=8332

Running Bitcoin

~/.bitcoin $ bitcoin-qt
"sni-qt/2440" WARN  16:37:44.104 void StatusNotifierItemFactory::connectToSnw() Invalid interface to SNW_SERVICE


texts: In Bitcoin scripting, can you have an IF within an IF?

texts:
In bitcoin, you can create a script like this:

OP_1 OP_IF OP_RETURN OP_ENDIF

But could you place another if statement inside the first?

OP_1 OP_IF OP_1 OP_IF OP_RETURN OP_ENDIF OP_ENDIF

I grant that this is a bit of a silly example (given that the whole thing could be replaced with OP_RETURN) but is that a valid script?


texts: Legal issue of bitcoin investment in the US as a foreigner

texts:
So after China banned CNY <=> bitcoin trading, I plan to invest in bitcoin with my USD. My plan is:

exchange USD with CNY (by wire probably)
Buy bitcoins with USD
Sell bitcoins for USD.
Exchange back to CNY (by wire).

In the above proccess, is there any legal issue against money laundering law of the US?


texts: I am new to Bitcoin, can anyone tell me how I can access to my RPC console and type in commands. I am using Bitcoin Core on my PC. If there is a tutorial for beginners to access to RPC please notify me.


texts: Transaction has been unconfirmed for two days

texts:
I have bought Bitcoin from a BitcoinATM in Romania and my transaction has not been confirmed yet. I e-mailed them and they told me "the network is busy but your transaction will be confirmed at some time". I have a couple of questions here:

They gave me a coin.cz URL of the transaction (https://coin.cz/address/35FC55vyEZr29jYPZKpVTYpiEThCaNqDYs) and it appears as unconfirmed, but if I search it on blockchain.info it does not appear at all. What is coin.cz and why does my transaction not appear on Blockchain.info?
Are there any chances that my money will be lost? What can I do to make sure they will give me my money?


texts:
I am trying to get information about my transactions from my wallet,

I use Listtransactions, and get all the information, but the time/blocktime/receivetime - there are all in number i can't decipher "1390424516" i thought they were ticks, but new DateTime(1390424516) gets me 01/01/0001 00:02:19 ...
I tried using them as seconds, i got to year 0045...

the documentations says
"time" : time associated with the transaction[1].
From block timestamp, unless transaction was already in memory pool then the local time when the client added the transaction to its memory pool

so i tried both methods on Blocktime too, but can't figure out how to get the time...


texts: If we want to check that data is member of it or not we will take the root, data block, and all the blocks in path between data and root. According to this picture if i want to check that data block, then how can i validate the hash pointer store in above block without having left child?


texts: Send funds from a specific address with bitcoinj

texts:
I have two addresses in my wallet.
I use one of them as a buffer and clients can receive money only from that address.
How can I send money from a specific address?


texts: Blockchain syncing seems to be stuck bitcoin core wallet

texts: I installed bitcoin core wallet  and it work for a month, now  syncing seems to be stuck on calculating progress increase per hour and nothing happens. how do I know if the syncing is progressing?


texts: Is bitcoin client really downloads the full transaction info?

texts:
I started learning bitcoin and found this wiki: https://learnmeabitcoin.com/beginners/network
And there is this statement:
When you run the client it will connect to other nodes and start downloading a full copy of the blockchain (the file that contains all the verified transactions). After that, your client will start receiving transactions from other nodes and relaying them around the network.
Is it really true that each bitcoin client downloads the full transaction history?
Unsure if that scales...
And if someone could provide a good official doc about explaining how bitcoin works?


texts: Open-source blockchain explorer for regtest mode

texts:
I'm trying to find an open-source Bitcoin blockchain explorer that will work in regtest mode, so I can more easily inspect the blockchain, see what transactions are getting processed and included, etc.

I found the following ones, but all of them seem to have issues:

blockcypher is "not easily compatible with running your own version locally, and this is no longer recommended (except for expert users)."
bitcoinchain is not open-source AFAICT.
Bitcore's insight-ui [1], [2], [3] does not work with bitcoind AFAICT.
toshi does not work with bitcoind AFAICT. Not sure how to set it up in regtest mode to connect to another bitcoind full node.
bitcoin-abe does not seem to support regtest mode, though it could be as easy as adding a new Abe/Chain/Regtest.py file.
blockchain.info: can't really tell if the My-Wallet-V3-* repos [1], [2] are for the block explorer website or for the wallet-management side of the website.

So, any suggestions for an easy-to-setup blockchain explorer that works with a local bitcoind node ?


texts: Blockchain for internet-of-things or is there any mining algorithm that can be utilized in low-computational power devices preserving security?

texts:
Recently IBM and Microsoft showed their interest (IBM post, Microsoft post) in utilization of blockchain for internet of things development.
Let's assume that in close future the blockchain technique to be implemented in smart cars overlaying road conditions or traffic data to each other.

Since the majority of honest nodes will be low-computational power devices (maybe like raspberry pi) it will be easy for adversary to perform a double-spending attack if implemented mining algorithm will not be able to bottleneck mining capabilities of devices.

Is there any mining algorithm that can resist nodes with high-computational power to a certain extent, so the blockchain can be utilized in a network of low-computational power devices?
From security perspective is it possible to allow only certain devices connect the network (let's say if they will somehow proove that they are limited in computational power within acceptable range defined by network)?


texts: I stored 0.0154 BTC in my blockchain for mining purposes and next morning I found my balance to be 000, what does that mean? Are my coins lost or stored somewhere else?


texts: What is the right way to create a MultiSig?

texts:
After following https://github.com/wobine/blackboard101/blob/master/wbn_multisigs_pt2_spend-funds.py for creating a MultiSig, I end up with a Multisig address.

On Validate Address it shows as valid but isMine:false.
I have send some test coins, still list unspend shows up as an empty array.
I validated the public addresses and all belong to the same wallet.
Txn shows up with confirmations on blockchain.info

So, my question is, is it the right way to create it? Or am I missing something.


texts: How to create ECPoint from raw private key

texts:
How to create a bouncy castle ECPoint from a raw private key hex string?  I am getting a private key using the 'dumpprivkey' RPC and removing the header byte and the 4 bytes of checksum + 1 byte of discriminator trailer bytes, resulting in a 32 byte raw key LIKE this example (this sample comes from here).  It causes the following exception.  Decoding public keys this way does not have this problem.

This is the code:

public static void main(String[] args) {
    String priv_key = "E9873D79C6D87DC0FB6A5778633389F4453213303DA61F20BD67FC233AA33262";
    BigInteger value = new BigInteger(priv_key, 16);
    ECCurve BITCOIN_CURVE = new SecP256K1Curve();
    ECPoint point = BITCOIN_CURVE.decodePoint(value.toByteArray());
}

But it results in this exception:

Exception in thread "main" java.lang.IllegalArgumentException: Incorrect length for infinity encoding
    at org.bouncycastle.math.ec.ECCurve.decodePoint(Unknown Source)
    at Btc.main(Btc.java:19)


texts: How long should I expect to wait for payout on p2pool

texts:
Basically, I have 20 GH/s running on p2pool I've had no pay out for about 4 days which seems a long time.

The time to share is also 110 hours and stays at 110 hours. It never drops and so am getting 0 shares in 5 days.

Basically my question is this normal? will it suddenly kick in or is there something wrong with my setup.


texts: Unknown Address Format Parsing Bitcoin Addresses from Blockchair Data

texts:
I've obtained a list of all current Bitcoin addresses with balances from Blockchair, which is downloadable from their data repository located here.  I have downloaded the Bitcoin / Addresses TSV database dump.
The list consists of:

~23m P2PKH (1xxx) addresses
~5.8m P2SH (3xxx) addresses
~1.3m Bech32 (bc1xxx) addresses

However, there are also ~400k addresses that have prefixes that I don't recognise, including:

d-xxx (example: d-b697921d996831d1a26ca8d8e92571c1)
m-xxx (example: m-942943e227462513f33c4f32ec6f1e56)
s-xxx (example: s-2ad548f2459c0ed6123400e5d61a479e)

Are these valid Bitcoin addresses?
If they are, how do I view information about them?
If they are not, any idea why they appear in the dump of current Bitcoin addresses from Blockchair?


texts: Why is the root seed of an HD wallet undergo an additional HMAC-SHA512 hash to generate the master private key and master chain code?

texts: From what I understand, the wallet seed is created by inputting into PBKDF2 (using HMAC-SHA512 of which 2048 rounds are applied) a bunch of mnemonic code words and an optional salt (defaulted to "mnemonic").  This generates a 512 bit-seed that is completely impractical to brute-force. This is a picture of the process that I am referring to taken from Mastering Bitcoin. Why, then, is it again hashed using HMAC-SHA512, besides for creating 512 bits of output (in the case where it originally might have been 128 or 256)? Why not just use a SHA512 hash alone (assuming the reason is just to create 512 bits)? What is the point of the HMAC here? Length-extension attacks should have been avoided from the previous iterations during PBKDF2, no?


texts: I'm trying to sign an input in my transaction. The question is: which key has to be used in the "script," private or public? It would be silly to disclose a private key there, right? But how will the network be sure it's me, if I provide a public key (which is known by everybody)?


texts: Checking/polling a balance of an address in Electrum via the command line/RPC

texts:
Suppose, I've dynamically -- via the command line/RPC -- created an address or payment_query in Electrum. And saved its details in a database along with the amount of bitcoins I expect to receive.

How can then check/poll if that amount of bitcoins has arrived to that address? Also via the command line/RPC.

I don't want to be notified by Electrum, rather I want to poll Electrum daemon myself. Hence an http request-callback which Electrum can send to a URL isn't an option I'm looking for. Also, at the moment, I don't have a blockchain locally. Maybe later I'll add it, though.


texts: Bitcoin private key, location on ECC curve

texts: In the ECDSA algorithm, the Bitcoin private key is supposedly a point on the graph (or is it?).  But the private key is a single integer, and not x,y coordinates.  Is the integer, by itself, the x value or the y value?  If it is x, then what is y? If it is y, then what is x?


texts: How to unset fee rate after setting with RPC `settxfee`

texts: After setting the fee rate with settxfee -- how do I re-allow bitcoind to set the fee automatically again? Or does the settxfee command only apply to the next outgoing transaction?


texts: crypto currency exchange and cold storage

texts:
Most of the crypto currency exchanges use cold storage for depositing bitcoins.
I was wondering if they maintain a cold storage for individual user or if they have one large cold storage for all users? does it provide benefit for storing offline wallets for individual users for a crypto currency exchange?

Thanks


texts: Is there any point mixing coins if I were to use an online wallet?

texts: Because when using an online wallet there isn't an address tied to your identity, would there be any reason to mix coins when making a transaction?


texts: How do you build a Ripple gateway without rippled?

texts:
I've noticed that several Ripple gateways now exist, most notably Bitstamp. However, the only documentation I can find on how to create an automated gateway seems to imply that you must have OpenCoin's rippled program.

Can anyone build a Ripple Gateway, or is this ability limited to OpenCoin's inner circle?


texts:
I was under the impression that miners earned coin from the blockchain (creator/owner/pool) or "Created" the coin they are paid??
But I see now that fees are involved to buy/sell/transfer.

For example I had $21 dollars left in in my wallet and wanted to transfer it
to GDAX, I was not able to because of insufficient funds to transfer.

Can someone explain how this works. (seems very expensive)


texts: Is it possible for the network to stop finding valid blocks?

texts:
The hashing problem is by design computationally hard, because SHA-256 hashes are for all intents and purposes random strings with no direct link to their inputs, and there's no (known) way to generate a block so that its hash computes to a given output (or, more exactly, satisfies the current difficult criteria). At any given difficulty level, there will only be a certain probability for miners to find a valid block.

Ok. But is there any proof that a valid block will actually exist at a given difficulty level? Is it possible that valid blocks just stop being found if difficulty increases too much? How could the network handle such a situation, if the difficulty level can only change every X blocks?


texts:
I found this site:

http://guadagnarebitcoins.altervista.org

What do you think? Is it a scam? Are the things listed on it scams?


texts: Why didn't Satoshi make the nonce space larger?

texts:
I know Satoshi isn't around to ask anymore, so this might be futile to ask, but I'm hoping someone might have some insight about this.

Bitcoin mining typically utilizes an extraNonce (bnExtraNonce in the coinbase tx's scriptSig) and a nonce field (32 bits). Why didn't Satoshi just make the nonce field larger, and then there wouldn't even be a need for the bnExtraNonce? Is there some reason why the nonce field needed to be kept to 32 bits? Seems like it would have been simpler to have a 64 bit integer in the block header. Even if he was worried about having an integer that was more than 32 bits, the header could have just been interpreted as two 32 bit integers nonce1 and nonce2.


texts: Why were custom scripts made non-standard except if they're P2SH?

texts:
Custom script = nonstandard
P2SH custom script = standard
Why don't  we set non-p2sh custom scripts standard too? Forcing P2SH requires adding hashes to the chain causing more bloating


texts:
I don't understand what the 'ScriptCode' thing is. Is it a part of transaction format? The wiki https://en.bitcoin.it/wiki/Transaction describes scriptPubKey and scriptSig, mentioning nothing about 'ScriptCode'.

When viewing an example P2WPKH transaction here http://n.bitcoin.ninja/checktx?txid=d869f854e1f8788bcff294cc83b280942a8c728de71eb709a2c29d10bfe21b7c

The "Script Code" field is displayed as "OP_DUP OP_HASH160 1d7cd6c75c2e86f4cbf98eaed221b30bd9a0b928 OP_EQUALVERIFY OP_CHECKSIG"(so the standard script used by ordinary P2PKH transactions), but these are not given by scriptSig or scriptPubKey(obviously, since those two have a very specific form required for SegWit transactions). Can someone explain where this stuff comes from?


texts: What libraries should I use for E-Commerce

texts:
We are developing some automated payment functions for Bitcoin. We want to automate transactions via a backend server setup; what libraries would be best suited?

I've found two libraries so far:

Java has BitcoinJ
C++ has bitcoin-qt

Would a thin or selfish client suffice ?

Do they support QR codes ?

P.S. I would prefer a Java over C++ coming from a C# background.


texts:
I have a question, I have like 0.1 BTC on my wallet from FEB 2013.

I am 34 weeks behind sync with bitcoin-qt wallet, but the weird thing is its encrypted but I think that i never encrypted it.

Is it possible it says its encrypted because its out of sync? or it is encrypted?

and also if u set a bitcoin password can it be something like: hello123 (the reason for asking is because maybe I can figure it out) if its something hard I probably wont remember it (randoms chars, e.g symbols).

EDIT: thing also is that in the menu I cannot choose encryp wallet ..


texts: How much energy will the Bitcoin network eventually consume?

texts:
A recent Bloomberg article stated that the Bitcoin network currently consumes about half as much energy as the Large Hadron Collider or enough to power 31,000 US homes. Even if the article is way off the mark, it is undeniable that the network's energy consumption (based on hash rate) goes up in direct proportion to the market price of a unit of the Bitcoin currency.

According to blockchain.info, the network is currently consuming 1,203.97 megawatt hours per day.

How much energy is the Bitcoin network expected to consume as the price of a bitcoin goes up from around $100 today to $1,000, $10,000, and so on?


texts: Will Confidential Transactions allow us to reuse addresses safely?

texts:
It is often said that, due to the natural transparency of the blockchain, one should have a multi-address wallet and try to not reuse addresses, so that the user's transactions are not so easily revealed.

Now, it seems at some point we will have the Confidential Transactions feature implemented in Core. So, when this moment arrives, will we be able to reuse addresses? Will it be safe to use a mono-address wallet?


texts: While Creating new CryptoCurrency should we create Smart Contract?

texts:
I have confusion in my mind regarding create own cryptocurrency.

Questions:
1.) I have created my own cryptocurrency using bitcoin or litecoin fork. So, From where to generate my original balance on initial bases? Because currently, I have created my own currency wallet from litecoin fork then it displays 0.0 MIND balance. So, if I want to transfer 100000 MIND balance while creating new currency then What should I do?

2.) Using fork create new crypto, Should I create a Smart contract for ICO? If yes, then what is the purpose of creating smart contract?

3.) If I am using fork litecoin, Should I generate my own Mining pool for mining?

Please let me know about my confusion. It is very important for me to understand above question's answer.


texts: Relation between transaction fees and inputs

texts:
So this might appear as a duplicate of some of the other questions on this stackexchange, but I feel most of the questions have failed to ask a question that I am really interested in.
I want to calculate the fee for my transactions. Now to calculate the fee for a transaction you need to have the number of bytes for that transaction, which are determined by the number of inputs. But the number of inputs a transaction needs, is decided by fee + amount to be transfered. Although usually the fee might be very small compared to the amount one would be transferring but I want to know how to calculate the fee in this case?
Any ideas on this concept on how to solve this issue, or maybe someone who could guide me if I am wrong on this concept would be greatly appreciated.


texts:
I am running bitcoind after previously running bitcoin-qt. I made a wallet with bitcoin-qt (and encrypted it) and I would like to open it now with bitcoind. The folder that contains the wallet.dat file is in the data directory, but when I run either of the following:

bitcoin-cli listwallets
bitcoin-cli getwalletinfo

it does not show my wallet. I have tried:

bitcoind -wallet="directory with wallet.data file"

and still no luck, it just tried to rund bitcoind and says it is already running (not sure why, I am running bitcoind -daemon).

Any idea how I can import this wallet?


texts: Lost my BTC, though my wallet is still available

texts:
Recently I have reinstalled Bitcoin qt because my HDD crashed. Fortunately I had a backup of my wallet.dat, but there is still one problem.

After the installation I replaced the wallet.dat with my old wallet.dat. If I start Bitcoin qt now, I can not see any money in my wallet?!

What can I do now?


texts: im a beginner and i hve what probably a simple question

texts:
I would like to know. If I do not buy a whole coin. and say I buy 40 dollars worth, or into a coin. how do I calculate the profit I make as coin rises. As I said I am beginner but i want to figure out how to get in the concurrency market.
any help would be a blessing i just want to buy some coins and maybe send my son to college one day. thanks


texts: Is HWI support for QR-code based HW possible?

texts:
I was listening to interveiw with COBO vault hardware wallet creator and at some point, he mentioned that because COBO is QR-code (sd card option) connected only (non-USB), it can't be supported by HWI.
Is it possible though to add QR-code data interface to HWI to support some functions (reading the xpubs, creating transactions)? And if yes, what would this support need in terms of dependencies?


texts: Would it be profitable to manufacture and sell my new mining hardware?

texts:
I am bit new with bitcoin. I run a electronics/software company in China and Australia. I would like to create new bitcoin mining hardware. The specs are as follows:

The miner is PCI-E installed, runs in a normal PC case or rack sized server around 200w, latest 28nm chip, around 200GHash/s, selling $99 (USD).

I will buy the chip from existing supplier. The design and manufacturing will be done myself.

Given I have a hardware team that have done many ARM Soc applications, and a reasonable experienced software people with Linux and software.

My question is it worthwhile the effort to do it? Is it profitable and what if any are the perceptive pitfalls?


texts: Can the blockchain be included in future packages of the standard client?

texts:
Is it possible to include actual transaction history to new version of Bitcoin client?

I mean, when someone new downloads a fresh version from http://bitcoin.org.

It is very hard to get more people into the Bitcoin community, when the start takes sooo looong.
(It looks like it never ends, like a bug.)


texts: Bitcoin exchange platforms and foreign exchange regulations

texts:
I'm wondering how cryptocurrency exchange platform adapt to country regulations where foreign exchange is forbidden (especially where sending money outside is forbidden).

How they could buy Bitcoin from outside without violating regulations (foreign exchange regulations), in the case if they don't have much liquidity to match international market price of Bitcoin ?


texts: Looking for a Bitcoin Cash (bch, bcc) testnet faucet

texts:
As the title states I am looking for a Bitcoin Cash faucet. I know about the very nice one:

https://testnet.manu.backend.hamburg/bitcoin-cash-faucet

but it seems to be down at the moment. A google search does not yield any other faucets so I am not very optimistic.

Thank you!


texts: can I use same wallet/private keys twice

texts: can i use the seed words of my online blockchain.info wallet on a trezor so i create a trezor wallet which has the same private keys as my blockchain.info wallet?And in the future i will only use my trezor wallet for transactions: I will let the blockchain.info unused.


texts: Recovering an old Multibit wallet file (76 characters long)

texts:
I have a wallet file from 2011 back when I used to play around with Bitcoin.
I used an old version of Multibit which has since long been unavailable.
My wallet looks like this:
# KEEP YOUR PRIVATE KEYS SAFE !
# Anyone who can read this file can spend your bitcoin.
#
# Format:
#   <Base58 encoded private key>[<whitespace>[<key createdAt>]]
#
#   The Base58 encoded private keys are the same format as
#   produced by the Satoshi client/ sipa dumpprivkey utility.
#
#   Key createdAt is in UTC format as specified by ISO 8601
#   e.g: 2011-12-31T16:42:00Z . The century, 'T' and 'Z' are mandatory
#
U2FsdGVXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXsnQhpZ6
 2013-10-30T20:52:01Z
# End of private keys

I managed to get a version of Multibit HD from the web archive but this doesn't support this wallet.
I also tried using OpenSSL with the following command:
openssl enc -d -p -aes-256-cbc -md md5 -a -in C:\key\wallet.key.txt -out c:\key\wallet-decrypted.key.txt

This output a file which wasn't correct and gave a bad decrypt error. I know the password for this file.
Does anyone know the correct method of decrypting this?
UPDATE: While I'm at it, I found a whole bunch more .key files. This one has a different format:
org.bitcoin.productionm!œ;€ò=°´zXXXXXXXXXXXXXXXXXÌñ9,o( 2D
ä¢¦]5+¡XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXE}Û@nŸé(2

ÐáXXXXR#
org.multibit.walletProtect.2 ZYour wallet description`


texts: What is the difference between mauling and transaction malleability?

texts:
http://stevengoldfeder.com/papers/ZKCSP.pdf notes:

  The protocol presented in [5] is vulnerable to the so-called mauling problem, where an adversary
  which knows the hash identifier T of a transaction is able to come up with a hash identifier T
  0
  that
  is semantically equivalent to T (i.e. spends the same transaction, has the same value, and the
  same inputs and outputs). As the authors of [5] point out, there are many Bitcoin software clients
  that cannot handle transactions appearing in the ledger with an hash identifier which is different
  from the original one (namely, the one with which they were posted) [3]. This effectively makes
  the transaction unredeemable, causing problems when creating Bitcoin contracts [2,3]. While the
  authors acknowledge the mauling problem, their scheme only addresses mauling due to malleability
  in ECDSA signatures, but does not address mauling due to changing the script.

The reference [5] cited is Efficient Zero-Knowledge Contingent Payments in
Cryptocurrencies Without Scripts

This sounds a lot like transaction malleability. What is the difference?

If it is not the same, is mauling fixed by Segregated Witness?


texts:
I'm fairly new to bitcoin and today I sent 1 satoshi to my own adress using the standard wallet, and I was surprised that I couldn't do it without paying a 0.005 BTC (I think, can't remember the exact value) transaction fee.

As far as I knew transaction fee's were supposed to be voluntary, when did this get added? Is there no way to transfer bitcoins for free anymore?


texts: Has UTXO selection methods changed since activation of Segwit?

texts: Before Segwit, transactions were penalized higher fees for having more inputs than outputs due to the input size being larger despite those transactions actually decreasing the global UTXO set. Segwit corrects this incentive mismatch. Have wallets taken advantage of this by changing their coin selection algorithms?


texts: Recovering deposit from Coinbase Multisig Account

texts:
I was one of the ones who never received the email about Coinbase discontinuing service of their Multisig Accounts. I tried to use the tool to retrieve my funds and it is stuck on verifying amounts, it never goes further then Step 1. Is there another way to transfer my funds to another bitcoin account (hex/raw transaction)? I have my keys, password, and public address for the account from coinbase, but can't figure out how to get the funds out.

Nonelilian


texts: Can an attacker create many nodes that approve blocks without work?

texts:
There are currently about 7000 nodes in the Bitcoin network. The security rests on the fact that someone adding nodes would have have to expend CPU power to hash transactions.

What prevents someone from creating a large number (e.g. 10,000 to 20,000 or more nodes) and then execute the following attack.

The objective of the bogus network would be to appear to anyone, except for the legitimate nodes, as producing legitimate verification of Bitcoin transactions without actually doing the work. While the legitimate network would know something is wrong; to those outside it would appear that a majority were approving the transaction.

The bogus nodes run a stripped down version of Bitcoin which accepts new blocks from other bogus nodes, but not new legitimate ones. The bogus software is designed to make the blocks look as real as possible, chain together, but without requiring the true proof of work. The nodes could be bots on compromised computers.

The nodes might do something like:

1) Gather any transactions sent to the network, including ones with invalid signatures and perhaps other invalid information, including thefts by the schemers.

2) The nodes in concert generate the block header and hash, by hashing once with some pre-aggreed upon nonce. They don't bother to do the repeated search.

3) All the bogus nodes accept the new block, send their acceptance out to the network and start creating the next block


texts: Is this scheme for multisig audit of Trezor + Coldcard ok?

texts:
My plan is to make a multisig between coldcard and trezor. I want to audit and verify that I indeed own the 2 keys of these wallets, using a raspberry pi zero (no wifi/bluetooth by definition) on a very old HDMI tv with no internet either, and using a virtual keyboard and simply a mouse on the pi zero.
These are the possible risks I want to mitigate:

The wallets can have a malicious random number generator.

The wallets can generate address for keys that are not mine

To eliminate the risk of the trezor generating a private key I don't own, I'm gonna put its key on the raspberry pi zero and see that it generates the same master pubkey and shown in trezor. This proves I own this key, but it might be a kew that someone already owns. No problem, that's why I'm doing multisig.
On the coldcard, I'll generate a seed using dices, and then verify on the raspberry pi that those dice rolls indeed generate the private key shown by coldcard. This proves that I own a private key that no one owns, because it was generated using dices.
Now that I have 2 private keys that I own, and at least one of them I'm the only owner, I can create a multisig wallet on Electrum or maybe BlueWallet. I'll annotate the first 10 addresses generated by the software wallet, and verify if they match on the coldcard and on the trezor. If the 3 show the same 10 set of addresses, I can consider these addresses safe for receiving Bitcoin.
I'll then receive some Bitcoin on one address, erase both wallets, restore them with the private keys, and then try to spend this Bitcoin, just to make sure I really owned the coins.
What are the possible problems I can encounter? Am I forgetting something important?
PS: I know that if the trezor has a malicious random number generator and it creates a private key that not only myself own, this is a privacy leak, but not a problem. And it's a privacy leak only when I spend from this address, revealing the public key on the blockchain.
I also plan to use just PBST air-gapped transactions on Coldcard, and a trusted computer to broadcast.


texts: How does a wallet get the public key from an address?

texts:
I was under the impression that addresses are just an encoded, hashed public keys with a prefix and that only the public key is used on the blockchain (not the address) for transactions.
But if the public key is hashed, how does the wallet get the public key from the address to create a transaction?

I did some research which confirmed my doubts that this is not possible. So I was wondering, how does the wallet create a transaction if it doesn't have the public key?

EDIT:
I mean how does someone trying to send 10 BTC get the public key of the receiver for pay to public key from the receivers to address. I fully understand the cryptographic element of private & public keypairs and how bitcoin is spent just not how the public key of the receiver is derived from the address. What I have seen is that (most commonly) transactions are pay to public key hash (P2PKH) rather than what I originally thought which was all txns are pay to public key (P2PK).


texts: A transaction that does not get processed

texts:
Yesterday I moved 20 bitcoins from my wallet in MtGox to my personal wallet, twice. The two transactions were made in a short time (about 1 minute). Both were done toward the same recipient: 142fUrgXNJiKwhXWiN9gkR8zvTbucm2idA
The ID of the first transaction was:

63eddec307c6ab9bf285b6b33f506fe90069e5d297263ed55249580a8120fff7

And of the second was: 67d1c656a65dc4c29f20292f4abecdb45d5a492091a167a0643fd50723f61dbf

Both transactions were registered from my MtGox account lowering it of said amount (thus taking away the possibility to try again).
Well, the first appeared immediately in my wallet, And after a few minutes gathered the confirmations necessary, and is now happily sitting there. The second never appeared. It did however appear on Blockchain:
https://blockchain.info/tx/67d1c656a65dc4c29f20292f4abecdb45d5a492091a167a0643fd50723f61dbf

Where it is sitting in a queue from yesterday evening with a confirmation warning saying: "This transaction has a none standard input".

So I would like to understand what is going on. What shall I do to recover those bitcoins?

Thanks,
Pietro

P.S. Note that making a search on the warning on google shows only one result: the code in github. So no one must have had this problem before. Weird.


texts: Sending Bitcoins from a Mastercoin Address

texts: Is there any danger in sending any remaining bitcoin funds that are still sitting in a Mastercoin address, i.e. the bitcoin address from which one sent funds to the Exodus address?


texts: Tracking outgoing transactions & malleability attack

texts:
What is the best way (in terms of security or resources) to track my outgoing transactions through the RPC API?

I would like to be able to track them down using their tx id and also to have a fallback mechanism for when my outgoing transaction's id changes as a result of a malleability attack.


texts: Have the security vulnerabilities found in Bitcoin been fixed in other altcoins?

texts:
This page maintains a list of vulnerabilities found in Bitcoin, and when they were fixed:

https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures

Are major altcoins, being based off of the same code, vulnerable to the same attacks? If so, have they been patched?


texts: What is meant by getnetworkinfo: networks: reachable = false

texts:
What do all the reachable: false's mean under each network? My node is connecting fine to other peers both in and out, I assume via IPv4 (since I didn't configure anything else special). Is my node reachable or not? Or does reachable mean something else in this context?

  "networks": [
    {
      "name": "ipv4",
      "limited": false,
      "reachable": false,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "ipv6",
      "limited": false,
      "reachable": false,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "onion",
      "limited": false,
      "reachable": false,
      "proxy": "",
      "proxy_randomize_credentials": false
    }


texts: How long does it take to transfer btc with 5 sats

texts:
I transferred 10 dollars to a gambling website and its been over a day and it still hasent reached its first confirmation, when will it actually hit it?
https://explorer.bitcoin.com/btc/tx/6d114e6f8d96f53a1aa8b9e8e6d66eeb4aedc4efa57d537a25f54bb7157f0ccb


texts: Is possible specify who can send bitcoins to me?

texts:
I have an idea to store data in OP_RETURN, but…

The main problem is it need to easy to review all the transactions. I mean, every user need to have access to the OP_RETURN, giving the public key address. But, most block explorers show all transactions, by default. The “blockchain.info” shows all the transactions, a common user will not use the “Filter”.
Someone are capable to send many “small fractions” of bitcoins. In this way a user will see many transactions, creating some “pollution”. Also, the software will need to filter it, because the fee will be higher than bitcoins that the “malicious users” are sending. Also, the software need to get all the OP_RETURN too, so they need to check one by one.

My solution is simple, restrict who can sent the bitcoin. In this case, anyone could know my public key, but no one can send bitcoin to it, only allowed people. So, I can restrict the address X to send me a bitcoin, but the address Y can’t.

It’s possible in the Bitcoin? If not how is the easiest way to make it easier for software and for a user?


texts:
I have changed the amount of coins to be mined, to be 1000 but looks did not work, I have already 8000 coins mined, can someone explain why it is not working?

main.h

static const int64 MAX_MONEY = 1000 * COIN;  //coin limit

static const int COINBASE_MATURITY = 2;

return dPriority > COIN * 1000 / 250; //after 10 blocks the dificulty will reajust


texts: Is it possible for the miners to collude to blackmail a single wealthy address?

texts:
Imagine if a few miners who together control more than 50% of the network hash power decided to charge higher transaction fees just for addresses containing really large sums.

For example, this address here has 69,471.08443061 BTC:

http://blockchain.info/address/1HQ3Go3ggs8pFnXuHVHRytPCq5fGG8Hbhx

Now the miners could decide to reject any transaction going out of that particular address (no matter how small the amount) unless it included a 25% transaction fee. You could call it extortion.

Question:

Is it "illegal" (see below) under the rules of Bitcoin?
How would the rest of the network detect such a problem (given it involves only one particular address)?
How would such a problem be resolved?

By "illegal" I don't mean the network would reject such behavior, because that it wouldn't, but that it would be rejected by most participants in the Bitcoin economy based on an implied understanding of what's fair and what isn't.

[UPDATE]

OK, let's say the mining cartel publishes their new policy on their website and word goes around.

Also, as an incentive to the rest of the participants in the economy, it is announced that part of the higher transactions fees will be distributed to everyone. This is achieved by setting up a single address (a la SatoshiDice) where you can send any amount and in return you'll receive the same amount plus the bonus. You can only do this once per address, because the program checks that the funds don't cross the same address twice.

You could call this a wealth tax or a "Robin Hood tax."


texts: Thanks for any link/author+title. I prefer max. 2 years to the past if possible. If you know about some book that will be published in the near future, you can mention it too.


texts: What is the proper way to update C-Lightning?

texts:
I downloaded the latest github .zip for version 0.6 and unpacked it but when I check the version I am running it returns:

v0.5.2-2016-11-21-1644-g1616fcb

Any idea what I did incorrectly? What's the proper way to update C-Lighting from the terminal in Ubuntu?


texts: When will Litecoin be fully mined compared to Bitcoin? And at what years will each halving occur?

texts: Bitcoin will be fully mined in about 100 years. When will Litecoin be fully mined for its 84 million? And in what year will each halving occur for Litecoin?


texts:
I am trying to run this code with node and bitcoinjs-lib but I keep getting missing lib.

Any idea what am I missing?

I am on a Windows Server 2016. I try to create a P2SH address by hashing a redeemScript.

// OP_HASH160 {scriptHash} OP_EQUAL
var bitcoin = require('bitcoinjs-lib')
var bscript = require('../../script')
var types = require('../../types')
var typeforce = require('typeforce')
var OPS = require('bitcoin-ops')

function check (script) {
  var buffer = bscript.compile(script)

  return buffer.length === 23 &&
    buffer[0] === OPS.OP_HASH160 &&
    buffer[1] === 0x14 &&
    buffer[22] === OPS.OP_EQUAL
}
check.toJSON = function () { return 'scriptHash output' }

function encode (scriptHash) {
  typeforce(types.Hash160bit, scriptHash)

  return bscript.compile([OPS.OP_HASH160, e216c9ev2d0drec3xxxxxxxxxxxxxxa3b5576d9176, OPS.OP_EQUAL])
}

function decode (buffer) {
  typeforce(check, buffer)

  return buffer.slice(2, 22)
}

module.exports = {
  check: check,
  decode: decode,
  encode: encode
}

Error is this below, but couldn't find this lib 'script'.

Error: Cannot find module '../../script'
    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (C:\Program Files\Bitcoin\rob\hash2.js:3:15)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)

Thanks!


texts:
I'm now comfortable generating public and private keys for each user of a website.

Is there any pro's / con's for generating the Private keys on the client in the browser or on the server?

And once generated is there any best practices for safely storing the users key?

I feel we need to store the key for the user as they can't be trusted to keep it safe and not lose it.

The connection to the website is all over SSL and the data center is ISO-27001 certified.


texts: Get transaction that spent a transaction id

texts:
The blockchain.info API allows for querying information about a particular Transaction by its ID. But if you want to follow the coins to the next transaction, I'm not seeing what the next query should be.

Each "out" of the transaction has an address associated with it, and you can query for details about a address' recent transactions. But if you're exploring deep in the past, the most recent 50 transactions for a given address won't have the spend for that particular "out".

So is there another API out there that allows you to query Transaction details based on "has transaction N as an 'in'"? Or do I need to go through the blockchain and make my own cache?

Edit: Blockchain.info clearly has the link to the transaction that spends a given output in their database, since the HTML view of a transaction now has "spent" tags after outputs that have been spent, which are links to the next transaction. However, that particular bit of data is not in the API view of the same transaction.


texts: Definition of confirmation time in blockchain.info

texts:
What will be the definition of confirmation time and data used for

https://blockchain.info/charts ?

I would appreciate confirmation.


texts: Largest number of bitcoins at a single address at one time?

texts:
What is the largest number of bitcoins that were stored in a single address at any one time to date?

I know there were >474320 BTC at this address at 2011-07-18 (identified to be MtGox's from the 424 242.42424242 transaction). Has any address ever contained more than this?


texts:
My address is 389CLh5Ect2i7U5116gqjBSLykYHRmdcgZ. In request from site i see this
scriptPubKey, how i can generate this scriptPubKey from my Address
{scriptPubKey: "a91446c443cc449d9e9a54a9e07a30dfd2ab1960a18f87", value: 60000} ?

If you have examples in javascript it will be good.


texts:
Who keeps the bitcoins?
If he didn't left to anyone his private key, will the bitcoins be lost forever and ever?


texts: In this transaction There's a decoding error and an escrow. What could cause this?


texts: How do I store coins during the bitcoin segwit2x hard fork?

texts:
Where should I securely store my coins during the fork? A Legacy address or a Segwit address?
I keep them on a Segwit address right now but I want to be sure that the fork won't affect my funds if kept on a Segwit address during the split.


texts: How to properly terminate a bitcoin-qt process?

texts:
I run my bitcoin-qt on headless raspberrypi where it runs pretty smoothly.
The Issue starts when Marco gui crashes via vnc so the Bitcoin-qt GUI is hanging although that deamon is still running as a process when i check with
ps -ax | grep bitcoin
In short I can't access the gui and close it normaly
the only way to still access is through ssh and I tried
bitcoin-qt stop
bitcoin-qt: cannot connect to xserver

What is the proper way to terminate/stop safely my bitcoin-qt process?


texts: I have lost the ‘seed keys’ (password) to my Mycelium soft wallet (which is on my old iPhone)

texts: I purchased Bitcoin several years go, it is on a ‘soft wallet’ (Mycelium is the name of the wallet) on an old I phone that is no longer used. Is this Bitcoin in any way recoverable?


texts: Relation between bitcoin price and other cryptocurrencies prices

texts:
If bitcoin price goes up, Will that increase the value of the other cryptocurrencies?

Edit: If yes, then WHY? Seems a mystery for me since I guess every coin has its independent price.

Thank you


texts: How do I broadcast an OP_RETURN transaction using bitcoin cli

texts: I am using Bitcoin Testnet's command line (and GUI). I am curious how, using my own computer and equipment (I already used a faucet) I could send a transaction easily. I tried https://github.com/coinspark/python-OP_RETURN and it failed because it is a newer version of bitcoin. However, I think I could use the CLI to broadcast a message.


texts: How does ImportPrivateKey get the Address if I don't explicitly send it?

texts:
Suppose I just used vanitygen to create this key:

Pattern: 1a
Address: e1aMGYXuGpUwDGH9gz3ZBs8UH746nRdEk6
Privkey: 5KhCszBi22hEZZixPEQkLAMtUVkxbGaxBFsH7a9iefqrxHmSXgH

All I had to do to import this key was import the Privkey. Nothing with "Address' was needed with ImportPrivKey.

I'd like to know the technical details on how the Address can be extracted when all that is known is the private key.

I've read this and this question, but still haven't found the secret sauce on how an Address is calculated or found in binary format given only a private key. How is the Address extracted from the private key alone?

My intent is to learn this process and implement it in C#. Note that I already know the Base58Check format, and there is no mention of the private key in any wiki I've seen regarding that.


texts: How much power for mining single Bitcoin or bitcoin cash?

texts:
Is there a fixed amount, or maybe just the average, power used to mine one single bitcoin coin or single bitcoin cash coin?

How low can the price fall until miners start red numbers?


texts: What is the hash-rate of the Bitcoin network that results in the maximum difficulty?

texts:
According to https://en.bitcoin.it/wiki/Target the target is a 256-bit number.
As the total hash-rate of the Bitcoin network rises, this number decreases to increase the difficulty. How much hash-rate (in terms of GHash/s) would cause the target to reach the minimum value? will the target ever get to 0? Does that mean it will be impossible to find a new block? (the minimum of a SHA256 hash is 0 which is not less than 0)