texts: Basic question about transaction verification

texts:
I am fairly new to crypto and had some questions about how transactions are verified by the nodes
Would it be correct to say that the full nodes check to see if the sender(Alice’s) signature is valid. And they check against double spends by seeing if the hash value that is included (of the transaction where Alice received the bitcoin) has ever been used an another transaction?
My question is, if that is the case, why can’t the verification only check against transactions signed by Alice, why does it have to check against the entire blockchain?
Why can’t it just check against Alice’s other transactions since you know she controls that coin.


texts:
If I am a merchant accepting 0-confirmation transactions I should protect myself against race attacks. Several resources state that I should configure bitcoin daemon to not listen for incoming connections (parameter -nolisten) and only connect to "well-connected" hosts (using multiple "connect=" parameter).

Question: How do I know which hosts are "well-connected" and suitable (long-running, no dial-up...)? Also it seems I can not rely on the mining pools because they probably have a limit on connections which might be already reached.


texts: How can a transaction have more than one recipient address?

texts:
I see a lot of transactions which have more than one recipient address.

Examples:

Transaction 1
Transaction 2

Edit #1:
I just saw a tag call multi-sig-transactions. It is obviously what I am asking for.

I did not see in the clients before. How come that there are so many of them?

Edit #2:
After reading little bit about multi-sig-transactions I am not really sure that these transactions are these multi-sigs. This opinion is not based on real knowledge but just on such a great number of these transactions in every block.


texts: how much data represents 1 satoshi? and on entire bitcoin

texts:
I mean, how many bits or bytes represents 1 satoshi, the minimun bitcoin portion
and how many bytes represents one entire bitcoin, not a block, a 1.00000000BTC


texts:
I have been doing a lot of reading up on bitcoin, but I can't find anything that explains how some technologies are used in conjunction with the blockchain.

From my understanding, the reason bitcoin is distributed is the blockchain is stored at multiple nodes (miners). When they validate transactions they get added to the blockchain and miners get a reward/transaction fee.

My current question is around civic. What would be the benefit to miners when it comes to a technology like civic (i.e. what would they mine and why)? What is the engine that keeps this data distributed?


texts: Difference between createmultisig and addmultisigaddress on v 0.20.0?

texts:
What is difference between createmultisig and addmultisigaddress? I ran 2 methods for 2 same bitcoin address on bitcoin-cli but gives different addresses as multisig to me. the results are as follows:
>  bitcoin-cli -testnet createmultisig 2 "[\"03f47a5115cd9e5e21b94136db90e2e3d6ac7e40396d8e62f73df3fd3fcfb3f214\",\"0395ad430034c1761bbe9b4dfd784fb06229970d54016a7e090fc6ceb3814611b5\"]"
RESULT:
{
  "address": "**2Mt1jgrBoojAHbJS5zGJTZnx4TFktUCCNxu**",
  "redeemScript": "522103f47a5115cd9e5e21b94136db90e2e3d6ac7e40396d8e62f73df3fd3fcfb3f214210395ad430034c1761bbe9b4dfd784fb06229970d54016a7e090fc6ceb3814611b552ae",
  "descriptor": "sh(multi(2,03f47a5115cd9e5e21b94136db90e2e3d6ac7e40396d8e62f73df3fd3fcfb3f214,0395ad430034c1761bbe9b4dfd784fb06229970d54016a7e090fc6ceb3814611b5))#6nexfs8d"
} ```

> bitcoin-cli -testnet addmultisigaddress 2 "[\"2NEy9um4CpWerPeaEhPa3TckNYWnh58yDXN\",\"2Mxr2oaph8iapbnbL1MSEvfZH8EQaXYuhAy\"]"

RESULT:
 {
  "address": "**tb1qjyvx2kwl4kq2cypj5zawhw5gpwxmphxe487z3hxj9m36ux8tylpszpazsu**",
  "redeemScript": "522103f47a5115cd9e5e21b94136db90e2e3d6ac7e40396d8e62f73df3fd3fcfb3f214210395ad430034c1761bbe9b4dfd784fb06229970d54016a7e090fc6ceb3814611b552ae",
  "descriptor": "wsh(multi(2,[a025344d/0'/0'/0']03f47a5115cd9e5e21b94136db90e2e3d6ac7e40396d8e62f73df3fd3fcfb3f214,[a025344d/0'/0'/1']0395ad430034c1761bbe9b4dfd784fb06229970d54016a7e090fc6ceb3814611b5))#gmdd9d2p"
}

why those addresses is different?
thank you


texts: Why unstuck transaction is sending again and again and how to solve this problem?

texts: I started Bitcoin Core with -zapwallettxes=1 and unconfirmed transaction came back to wallet. Next sent transaction was unconfirmed too. I repeated above action and resent transaction. It was unconfirmed again and do -zapwallettxes=1 again. Everything is looking good but after few minutes last transaction was sent again with out do anything my self. Where I'm wrong and how to find solution?


texts:
From this question I've learned that a transaction with N inputs requires N sign operations.

But what if there a huge amount of inputs? E.g. I have a coffee shop and I sell 5000 pcs coffee every day for $1 each. If I want to transfer my daily income I'll end up with a transaction with 5000 inputs.

Counting with 100kB max transaction size ~300..400 inputs can be included in one transaction. So I need to make 10..15 transactions every day. In addition, if I have a hardware wallet that needs let's say 500 ms to make a signature it will take 5000*0.5 sec = 41 min to sign all the inputs.

What is the correct way to handle this?

Is there an option to sign the transaction only once and use this signature for all the inputs?


texts: How is the distributed transaction log stored in P2P network?

texts: After mining, a block is validated and broadcasted by the miner. Then, where does this newly mined block get stored at? Where does my Bitcoin client pull the transaction data from?


texts: How does the Coin Selection in Bitcoin Wallet for Android work?

texts: What is the algorithm in Bitcoin Wallet for Android to select the inputs to create a new transaction?


texts: Error help! "A fatal error occurred. Bitcoin can no longer continue safely and will quit."

texts:
I synchronized fully, replaced the wallet.dat file, rescanned and this happened.

My debug log:
https://drive.google.com/file/d/0B7me4XCWsORySzdMMEpYWU5Lakk/view?usp=sharing

Screenshot of Error:


texts: Why number of zeroes in bitcoin hash is increasing?

texts: I know currently to mine a block there needs to be 19 leading zeroes in the hash, but why is this number increasing?


texts: What is differences of bitcoin mempool anchestor and descendant?

texts:
is there a specific explanation about the differences between mempool anchestor dan descendants?

there are RPC commmand for "getmempoolanchestors" and "getmempooldescendents". What is mempool anchestor and decendents it self?

each node may have a different mempool size, but what are the differences of the mempool anchestor dan descendants?


texts: What do the options in Bitcoin Core's wallet creation mean?

texts:
I'm a newbie and today I have wanted to create a new wallet and I have confused when Bitcoin Core (v. 0.21) has asked me for additional information.
It asks me:

Encrypt wallet - Encrypt wallet by a password.
Disable Private Keys - ???
Make Blank Wallet - ???
Descriptor Wallet - ???

What do these ??? mean?
What is the difference between Enable\Disable Private Keys?
Whare can I read detailed information?
I have found reviews only on the Internet and they have had two or three sentences about my questions.
Can anyone explain to me what does it mean?


texts: How to develop a crypto exchange leveraging on third party API like coinbase, blockchain.com

texts:
I got a request as a developer to develop a bitcoin exchange site like https://mypatricia.co/ or https://instantcoins.ng/ I am to leverage on third party API like Coinbase, blockchain, it could be anything reliable API.
Users will be able to buy and sell bitcoin. For instance USER A makes an offer. USER B is interested in USER A's offer. When USER B clicks a button, with be a switch from USER A's wallet to USER B's wallet. Before the EXCHANGE is done. USER B is prompted to make payment in local currency.
I have been looking at https://developers.coinbase.com/api/v2#introduction https://api.blockchain.com/v3 I dont know how to go about it.
Is there any other better ones to work with?
There will be some other endpoints like
Where users get list of their orders
check wallet etc
I will appreciate your contribution


texts: How do the Peercoin nodes verify a new block found by proof-of-stake?

texts: Is the method for verifying a new block found by proof-of-stake minting the same as if it were found by proof-of-work mining?


texts: What needs to be done inorder to change difficulty?

texts: I'm trying for a while to reduce difficulty of main network to do some experiments on transactions and maybe simulate some possible attacks.I came up to change nBits field in chainparams.cpp but it seems it is not enough and the new network didn't run properly. What else should I do exactly ?


texts: Isn't an encrypted wallet.dat automatically a "watch-only" wallet?

texts:
I have encrypted my wallet.dat outside of this computer. Now I store my wallet.dat on this computer.
If I open it in Bitcoin Core, I can view the balance but not spend it (without entering the decryption passphrase).
Doesn't this make an encrypted wallet.dat a "watch-only" wallet? Can't I simply safely keep this on my PC and use the RPC API to check on the balance to make sure that it still contains my coins?
Basically: What is the difference between an encrypted wallet and a "watch-only" wallet? Why would I make a "watch-only" wallet when the encrypted wallet apparently has the same functionality, and is as secure?


texts: Generating a Vertcoin public / private key using javascript and bitcoinjs?

texts: I noticed in the bitcoinjs library there are parameters to generate litecoin and dogecoin addresses. But how can this be used to also generate vertcoin addresses? Is this even possible using the same library or do you need to add in other libraries?


texts: Is Bitcoin's Economic Majority those who already own coins or those who will buy or keep coins?

texts:
The Economic Majority theory says that the power to control the Bitcoin protocol is held by those who [own] bitcoins.

But the article then goes on to read:

  The ability for a protocol change to be successfully implemented
  ultimately rests with those who accept bitcoins in exchange for value.

So that refers to investors and those who accept bitcoins for income or revenue but then aren't immediately spending or cashing out the coins they received.

But that power doesn't lie with those who already hold the coins but instead it lies with those who are willing to accept the newly issued coins under the revised protocol or coins with taint from coins issued under a revised protocol.

So, is the Economic Majority those that already hold bitcoins or is it instead just those who will hold the bitcoins generated following a change to the protocol?  If so, how would that be best worded?


texts: How are the unlocking script + locking script executed?

texts:
I just wanted to verify the input of transaction 7de75. The related output is index 10 of transaction 00f64.
The locking script defined in 76a91 (index 10) is:
OP_DUP
OP_HASH160
7ddb236e7877d5040e2a59e4be544c65934e573a
OP_EQUALVERIFY
OP_CHECKSIG

The unlocking script in 7de75 is:
3045022100b7393ff959120e3ccb5284e3cf2eaa200235643a1549a4e6faaa911619089e2b02207b677827c7beeb53503e016a8dd29164d07cb79f0f1e058df9b8dfa3568d029001
04c4b7a7f7bb2c899f4aeab75b41567c040ae79506d43ee72f650c95b6319e47402f0ba88d1c5a294d075885442679dc24882ea37c31e0dbc82cfd51ed185d7e94

I've concatenated both:
3045022100b7393ff959120e3ccb5284e3cf2eaa200235643a1549a4e6faaa911619089e2b02207b677827c7beeb53503e016a8dd29164d07cb79f0f1e058df9b8dfa3568d029001
04c4b7a7f7bb2c899f4aeab75b41567c040ae79506d43ee72f650c95b6319e47402f0ba88d1c5a294d075885442679dc24882ea37c31e0dbc82cfd51ed185d7e94
OP_DUP
OP_HASH160
7ddb236e7877d5040e2a59e4be544c65934e573a
OP_EQUALVERIFY
OP_CHECKSIG

and executed it via bitcoinIDE. However, OP_EQUALVERIFY failed. Could somebody explain to me where I made a mistake?
edit: I think Rene Pickhard explains the issue here but I cannot follow the explanation


texts:
Looking at transaction https://blockstream.info/tx/c362fe7f8cb94b363c0c7cd5a0f82cf0dfa7733ab8a3b90df3eb9f0bff912148 some outputs are having type: nonstandard.

There are 2 questions related to it:

Wouldn't this construct be interesting from the perspective of obscuring data against blockchain analytics?
Where can I learn more about transactions like this one? Why does it have something that looks like a multisig definition in the output?


texts: Can't get into my MultibitHD wallet. I have the 18 recovery words but can't recover the wallet

texts:
I'm trying to login to my MultibitHD wallet and its saying the password won't unlock the wallet. I might have forgot the password, but I have a feeling I'm using the right password.

I have the 18 words to recover the wallet (I regret making it 18 words, I should have stuck with 12 words so I could import it using another wallet) but heres what happens when I try to recover the password:

It just gets stuck on that last page, nothing happens. Over the years I'm always running into problems like this with MultibitHD, usually I can recover it with the words though. This time I can't. I have about €100 of bitcoins in there so this is a problem. I tried to restore the wallet from a backup point but that didn't work either. Is there anything else I can do?


texts: Person did not receive the amount of bitcoin I sent

texts: I sent $4300 in bitcoin to my friend and he only received $415. I'm so upset because I lost over $3500.  Is there any way to get this corrected?


texts: With getpeerinfo command I can get all directly connected peers ip addresses, how to know mine in the bitcoin network?


texts: Where does bitcoin-qt store it's initial settings

texts:
I installed bitcoin-qt (v 0.12.1) on Kubuntu 15.10. When starting it the first time the GUI asked me for the datadir. I set it to an external disk.

Where are this settings stored? There is no bitcoin.conf file in my /home/<user>/.bitcoin/ directory.

I know, that I can manually create the bitcoin.conf file. But I'm just curious, where the settings are stored, if no such file is present?


texts: How can I generate a database/list of all non-empty bitcoin addresses with their current balance?

texts:
After downloading the full blockchain, how can I parse it and generate such a database?
Can you point me in the right direction?


texts: Bitcoin wallet to be integrated into a Webapp

texts: Does anyone know if exist a Bitcoin wallet that allows to be integrated into a Webapp? I mean a kind of Metamask for Bitcoin. What I should do is develop a Dapp that allows the user to send txs from it without implementing the key management part.


texts:
I'am learning about Bitcoin and I didn't understand something.
Maybe someone could clarify.
I [think] I understood what Segwit does (increases block size, solves malleability and works better with Lightning Network).

What I don't understand is how an increased block (4MB) is considered valid by old clients (without segwit)? Don't they verify the whole block size including here everything also signature (witness)  that is segregated?

On blockchain explorer I see 3992.604 kWU and 800 transactions for block #512446. What is 3992.604?? Bytes?
I understand the acronym kilo weights unit but what are those weights?

Thanks you


texts:
i created new service which is using bitcoin for payment. I am bit struggling with Bitcoin community and don't know what to do next.

Recently i
- i added service to bitcoin.it wiki
- created announcement on bitcointalk.org
- added link to reddit /r/Bitcoin

Is there any other possibilities to let the Bitcoin community know about my service?


texts: Where can I find a complete list of Bitcoin forks (soft, hard, intentional and unintentional)

texts: I was looking to study the history of Bitcoin forks including the 2013 incident that may or may not have been a Hard fork depending on your definition.


texts: Maximum number of inputs per transaction

texts:
In theory, what is the maximum number of inputs per transaction? Is it defined primarily by the maximum number we can store on the 9 byte varint?

How big of a number can be stored on 9 bytes?

Would such a transaction even fit in a block if it had just 1 output?


texts: What is the difference between a hard fork and a soft fork?

texts: A fork is a splitting of the blockchain. But what is the difference between a hard fork and a soft fork?


texts: How often does peercoin minting pay out?

texts: If I have a peercoin wallet and generate coins with the PoS system, how often does it pay me the 1%? Can I change this to every week/month/half year?


texts: Bittrex API OpenBuyOrders OpenSellOrders - what do they actually show?

texts:
e.g. https://bittrex.com/api/v1.1/public/getmarketsummary?market=btc-bcc

shows:

{..."OpenBuyOrders":1557,"OpenSellOrders":13944,...}

What do these numbers refer to since they do not match the BTC or BCC bid and ask volume values on the bittrex screen when looking at this pair.

Any ideas what these two values are showing? I need to know the total number of bid and ask BTC volumes via the API calls? Thanks


texts: How do you get "the raw bytes for the genesis transaction"?

texts:
This post

How to retrieve the from and to wallet addresses of a transaction?

contains code by Nick ODell which refers to a file called 'genesis.bin' which contains "the raw bytes for the genesis transaction". I wonder if anyone knows how to retrieve that data?


texts: How to test bitcoin distribution mechanism

texts:
Now I'm developing a bitcoin distribution mechanism (according to users' submitted shares count). The complete workflow is: Users submitted shares to my pool, then my pool submitted these shares to another famous pool (e.g. btcguild). When my pool received bitcoins from the remote pool, it will distribute these received coins to users (according to their submitted shares count)

The problem is that everytime I test this mechanism, I will create many transactions, but each transaction will take 0.005 btc as transaction fee for bitcoin network. Then after paying 200  users, I will pay 1 btc to bitcoin network, The cost is high. Is there any way to simulate the bitcoin network, so I can create transaction without paying transaction fee?


texts: I have a merchant that only takes bitcoins can I just put the correct amount in the wallet and then pay them?

texts: I want to pay a merchant who only takes bitcoin payments. Do I create a wallet and only put in the amount of the price and pay with it? If so then what do I do after I send it to the merchant?


texts: How to get pending balance in with bitcoinj?

texts: I'm try get pending balance from wallet, but results do not match with pending transactions? Thanks for advice!


texts: Please I want to ask how can I get the private key so to withdraw from my imported address and is it possible that you get to pay a certain amount of btc to get the private key..thanks in anticipation


texts: Hex to ASCII conversion of output scripts generates unexpected characters

texts:
Embedded in this transaction, there is a blockchain file upload tool written in Python.

I'm trying to convert the hex of the output scripts to ASCII, so I can assemble it all into an actual runnable Python script. However doing a direct hex to ASCII conversion generates some unexpected characters.

For example, the third output script has the following hex:

51412c756e6865786c6966790a66726f6d20646563696d616c20696d706f727420446563696d616c0a0a6966206c656e287379732e6172677629203c20353a0a20202041207072696e74285c0a2222225c0a55736167653a202573203c66696c653e203c6465737420616464723e203c6465737420616d6f756e743e207b3c6665652d706541722d6b623e7d0a0a5365742042544352504355524c3d687474703a2f2f757365723a70617373406c6f63616c686f73743a706f72746e756d22222220252073797353ae

Using a hex to ASCII converter, it becomes this Python code:

QA,unhexlify
from decimal import Decimal

if len(sys.argv) < 5:
   A print(\
"""\
Usage: %s <file> <dest addr> <dest amount> {<fee-peAr-kb>}

Set BTCRPCURL=http://user:pass@localhost:portnum""" % sysS.

Why is the character A preceding print for no reason? As well as QA and S at the beginning and ends, respectively?

From what I've seen referenced on the Web, the third output script is meant to look like this:

,unhexlify
from decimal import Decimal

if len(sys.argv) < 5:
    print(\
"""\
Usage: %s <file> <dest addr> <dest amount> {<fee-per-kb>}
Set BTCRPCURL=http://user:pass@localhost:portnum""" % sys.

What am I missing here? I'm completely new to Bitcoin, so I'm guessing it's something obvious.


texts: Is there a future-proof method of encoding messages in the blockchain?

texts:
There are several "reasonable" modifications to the Bitcoin protocol that would make some methods of encoding messages break (e.g. pruning).

Are any of the existing encoding methods future proof, in the sense that they are likely to continue functioning even after "reasonable" changes to the Bitcoin protocol?


texts: The bitcoin-qt synchronization just stopped

texts:
Someone recently stole the computer where my Bitcoin were. As my hard drive was entirely encrypted and as I had backups of my wallet.dat file in three different places, I'm not afraid of losing money, so that's not the problem here.

I bought a new computer, reinstalled everything including bitcoin-qt. I launched it and it started synchronizing with the blockchain. However, the sync process seems to have stopped, and hasn't moved since yesterday. When I put my mouse on the progression bar, it reads « Catching up… Processed 153771 of 264122 blocks [...] Last received block was generated 99 weeks ago. [...] », and it does not change. That's strange, because on the bottom-right corner, it reads that I have « 8 active connexions to Bitcoin network ».

Has anyone an idea of what the problem could be? I doubt that it is a connexion problem, because it first worked perfectly… I would prefer to make bitcoin-qt work rather than use another client.


texts: How does Bitcoin Gigahashes Convert to Ethereum Megahashes?

texts:
I bought 6 XFX Rx 480 8GB graphics cards and I estimate they will do 25-30 megahashes with Ethereum.

When looking on Amazon for other rig ideas I was reminded that they also sell Erupters. The erupters I was looking at are £60 roughly for 16 gigahashes. Not sure if that is only with Bitcoin or not but most of them say Bitcoin in the name/title of the product in sale.

I was wondering what this would equate to in ethereum megahashes and why?

My guess would be that it is something to do with the the difference in complexity with the encryption method, or something like that, but of course, for economy reasons the most important thing I would like to know, if possible, is what hashrate they would generate for Ethereum.

Thanks for any help in advance.


texts: Are there actually merchant services for "outgoing" processing?

texts:
I read this extremely informative QA:
My raw transaction destroyed 0.0284377 BTC. What did I do wrong?
For those of us new to the BTC universe, there can be confusion between BTC, exchanges, wallet service providers, BTC-related SAAS providers, and so on.
My question:

Notice that the OP in the question has some sort of business which both takes in and sends out BTC.

I mean to say, those operations are done automatically, by the www-based business in question.

Thus the business in question, has "some sort of software on a server", which, can both receive, and indeed send, BTC. So far so good.

What I am confused about:
it would seem to me that for such a common need, nobody would bother writing their own software to provide those two needs, because I assume, there are any number of large well-known services now which provide exactly that service?
(Obviously you might do it experimentally, or as the OP mentioned in the interesting question, it was done some years ago in the early days; or of course the largest enterprises might do it "from scratch". But surely normally there's just a service which does this via simple APIs?)
Thus, say I want to start a business called BitBall, which is a consignment warehouse for buying and selling baseball cards.  BitBall users ("type A") send in their baseball cards.  Other BitBall users ("type B") buy the baseball cards and they are shipped from the warehouse.
Obviously, "type B" users must spend BTC to BitBall, and "type A" users will have BTC paid to them from BitBall.
My question, it seems incredible that the BitBall programming team would have to program, from scratch, the BTC related software to enable type A receiving and type B spending ??
To repeat, my question is about an online operation which has to both send as well as receive BTC programmatically.
At first I just assumed the major services I had heard about (eg "coinbase") did this sort of thing but I was wrong. (I think!)
Again in short, surely there are (a number of? well-know?) let us say "merchant services companies" for the BTC universe, which handle both spending and receiving BTC?  For businesses (example - "BitBall") which both spend and receive?
Or really, do you just have to plain program it yourself from scratch?  Is there no such thing (yet?) as an in-and-out merchant services API service for BTC handling??


texts: How do I concatenate two hashes in Python?

texts:
Concatenating and double SHA-256 hashing

"a751efbeabe73bdf9d08df5760104feff915d9d807d4c62178cdeb98d8c25f43"

with itself

"a751efbeabe73bdf9d08df5760104feff915d9d807d4c62178cdeb98d8c25f43"

should output
15eca0aa3e2cc2b9b4fbe0629f1dda87f329500fcdcd6ef546d163211266b3b3

      import hashlib
      header_hex = "a751efbeabe73bdf9d08df5760104feff915d9d807d4c62178cdeb98d8c25f43a751efbeabe73bdf9d08df5760104feff915d9d807d4c62178cdeb98d8c25f43"

      header_bin = header_hex.decode('hex')

      hash = hashlib.sha256(hashlib.sha256(header_bin).digest()).digest()

      hash.encode('hex_codec')
      '2b4a9fdb97e89e73c4647791e476090eaad04f43c93a3de21a95d2c4fc8e8e0c'

I'm getting the wrong answer :/?


texts: What is the difference between bitcoinj and BitsOfProof?

texts:
bitcoinj is a bitcoin library, bitsofproof is a full server (standalone 'exe').

Beyond the above - can anyone elaborate on the difference between them? What problems they were designed to solve, their documentation, maturity level?

Is there an overlap between them (in intended usage)?


texts: Are wallets compatible with different clients?

texts: If I create *.wallet file in MultiBit, encrypt it with password and transfer some coins to it - does it tie me to this particular client, or can I open *.wallet file in any client


texts: Is lightning network censorship resistant?

texts:
I know this is a hot topic at the moment, and I really don't want to create some kind of debate here, i'm just interested in if this question is adressed. Any other place where I have spent time, it's impossible to get any good objective answer to this question because of all the politics. Stackexchange, you are my last hope.

As far as I can understand, the common expectation is that lightning network will be a distributed, but not decentralized. If one or more countries started saying to nodes that shovel a lot of bitcoin: "We consider you banks now and you cannot participate in a payment-routing unless you have Know Your Customer/Ante Money Laundering compliance on all participants in the chain, effectively splitting the lightning network into a legal and an illegal part, does the lightning network have any kind of protection against this?


texts:
I use createrawtransaction  for create a rawtransaction with [] "zero inputs" and one output.
I use fundrawtransaction for populate rawtrasaction with inputs.

{"method":"createrawtransaction","params":[[],{"mv8sTXT1FSAJENZNNoKb3BAHnersrC9c41":0.1}],"id":"null"}

{"method":"fundrawtransaction","params":["RESPONSE-CREATE-RAW-TRANSACTION",{"feeRate":"0.00031744"}],"id":"null"}

My question is, how many confirmations are the inputs added by fundrawtransaction? Can I configure the confirmations that the inputs will be selected?


texts: Can I set a zero fee to transaction if there is less transaction volume than space in the blocks?

texts:
I'd like to set a zero fee to transaction when block is spacious.

Is it acceptable and can be confirmed by network, miner on BTC, BCH, BTG ... these chain?


texts: Should I use Electrum Wallet OR Bitcoin Core as my website's payment gateway?

texts:
I'm a developer who is building a website that need to process Bitcoin payment requests. So I need a payment gateway.

In my last project, I used Electrum wallet as payment gateway but my last project doesn't have too much bitcoin payment requests, and electrum works fine.
But I'm afraid of electrum's limitations and I'm not sure it's a good idea to use electrum when processing lots of payment requests.

Bitcoin Core runs bitcoin node but it takes too much disk space (full node) or CPU usage (prune mode) and I'm afraid it's not a good idea too.

So please tell me which one preforms better as a website's payment gateway, and why. Thank you all for answering.


texts: How i get callback notification while BTC received to wallet

texts:
i installed bit coin core in my Windows machine [test-net] .i implemented a C#.net application using Bitcoin RPC command like generate address , transfer BTC to one address to another address. It working great.

My question is, how can I get a notification once an address that I generated receives a payment? How can I get a notification when the payment is confirmed?

Any help / guidance would be helpful.


texts: Mining Fee for the blocks that are orphaned

texts: Suppose a miner mined a block and the block got added in the main chain of the block chain. He must have got his mining fee then. Now suppose that due to a fork sometimes later, the block that he mined is no longer a part of the main chain, i.e. that block is orphaned now. Then would he retain his mining fee or would it get deducted?


texts: Being paid in Bitcoin from another country

texts: If I sold property in another country, could I be paid in bitcoin in a basic wallet to wallet transaction if the value is 500k+?


texts: Where are P2SH full redeem scripts stored?

texts:
A pay-to-script-hash/P2SH full redeem script can be up to 520-bytes in size. Just to clarify, prior to being revealed/spent, is the redeem script stored in the spender/Bob's wallet or elsewhere?

The developer guide says:

  "When Bob wants to spend the output, he provides his signature along
  with the full (serialized) redeem script in the signature script."
  (https://bitcoin.org/en/developer-guide#p2sh-scripts)

Soroushjp states:

  "The redeem script itself is only revealed, checked against the redeem
  script hash, and evaluated during the spending transaction."
  (http://www.soroushjp.com/2014/12/20/bitcoin-multisig-the-hard-way-understanding-raw-multisignature-bitcoin-transactions/)

Antonpuolous states:

  "P2SH shifts the burden in data storage for the long script from the
  output (which is in the UTXO set and therefore affect memory) to the
  input (only stored on the blockchain)." (2014:133)

(This question asks almost the same thing: Where the P2SH script gets written?)

(There's an unintended relationship with this question "Storing scripts (smart contracts) outside the blockchain", insofar as the location of redeem scripts.)


texts:
I started Bitcoin Core 0.20.0 and allowed it to sync with the network.

The synchronization was completed. However my balance is 0.00 and all transaction history is missing.

I tried to troubleshoot the problem. One at a time, I loaded the two wallet files (wallet.dat and default-wallet.dat) through bitcoind and checked the output.

Both these files were backuped from the last time I used Bitcoin in 2015.

Command:

bitcoind.exe -rescan -upgradewallet -upnp=1 -wallet=wallet.dat -datadir=.\..\BitcoinData

This line got me worried:

2020-06-10T20:19:03Z [wallet.dat] Keys: 0 plaintext, 0 encrypted, 0 w/ metadata, 0 total. Unknown wallet records: 0

Both wallets show this line.

Output pertaining to the wallet

2020-06-10T20:19:03Z [wallet.dat] Wallet File Version = 10500
2020-06-10T20:19:03Z [wallet.dat] Keys: 0 plaintext, 0 encrypted, 0 w/ metadata, 0 total. Unknown wallet records: 0
2020-06-10T20:19:03Z [wallet.dat] Performing wallet upgrade to 169900
2020-06-10T20:19:04Z [wallet.dat] External scriptPubKey Manager for output type 0 does not exist
2020-06-10T20:19:04Z [wallet.dat] External scriptPubKey Manager for output type 1 does not exist
2020-06-10T20:19:04Z [wallet.dat] External scriptPubKey Manager for output type 2 does not exist
2020-06-10T20:19:04Z [wallet.dat] Internal scriptPubKey Manager for output type 0 does not exist
2020-06-10T20:19:04Z [wallet.dat] Internal scriptPubKey Manager for output type 1 does not exist
2020-06-10T20:19:04Z [wallet.dat] Internal scriptPubKey Manager for output type 2 does not exist
2020-06-10T20:19:12Z [wallet.dat] keypool added 2000 keys (1000 internal), size=2000 (1000 internal)
2020-06-10T20:19:12Z [wallet.dat] LegacyScriptPubKeyMan::NewKeyPool rewrote keypool
2020-06-10T20:19:12Z [wallet.dat] Wallet completed loading in           10400ms
2020-06-10T20:19:12Z init message: Rescanning...
2020-06-10T20:19:12Z [wallet.dat] Rescanning last 634090 blocks (from block 0)...
2020-06-10T20:19:12Z [wallet.dat] Rescan started from block 0000000000000000000d972cc312510d2a4811854e3705a0693289d73065af75...
2020-06-10T20:19:13Z [wallet.dat] Rescan completed in             163ms
2020-06-10T20:19:13Z [wallet.dat] setKeyPool.size() = 2000
2020-06-10T20:19:13Z [wallet.dat] mapWallet.size() = 0
2020-06-10T20:19:13Z [wallet.dat] m_address_book.size() = 0

Should I assume the wallet keys are lost, or maybe this was a upgrade issue with the wallet. What should I try next?

Thank you.


texts:
Is it possible to change rules of mining bitcoin division?

rewrite P2P bitcoin client (or write maleware) which will be pretending that fake bitcoin client is legal, original client
distribute program more/less widely
then by fake client division of mining loot will be with fake/own rules (e.g. give more bitcoins to farm X, even if farm X didn't work more than others)

no changing keys
no faking difficulty level/spent time
maybe changing proof-of-work action


texts: Is the native Bitcoin client intended for mining?

texts:
I can't understand, a native bitcoin client for calculations - will he be able to take part in mining?
If not, what kind of native mining software should use? Does he even exist?
I only found third party products like cgminer, cudaminer, etc.


texts: Why does the halving event take place every 4 years?

texts:
So, as per my understanding - bitcoin halving takes place when 210,000 blocks are mined. And blocks contain transactions - and they contain the same number of transactions (more or less). So, as the popularity of bitcoin keeps on increasing, wouldn't more transactions take place daily?
And if that is the case, then more and more blocks would be mined every day. And bitcoin halving event would take place faster and faster.
The only way bitcoin halving event takes place around the same time every year would be if every block is holding more and more information as time goes.
What do you think? I am so confused.


texts:
I have just read this which talks about creating private blockchains and using a unique public/private key per transaction so you can't be traced. There are also "Zero-knowledge proofs" which I'm not too familiar about. But other than that it doesn't state much about how you can make the blockchain secure and protect privacy. In addition, private blockchains reintroduce the need for a central authority it seems, and unique keys per transaction means the keys need to be stored at great length and regenerated for every transaction, meaning a potential performance limit and memory tax.

So I'm wondering generally how you can make a blockchain that works at the level of atomic operations like an Instruction Set Architecture or Virtual Machine like Ethereum, and yet protect user privacy and not run into performance or scalability problems.

I don't know enough yet about how the ledger / verification process works, so I can't tell what it would entail. But I imagine you would essentially create a dynamically changing user ID like the public/private key, and have a block-chain per user that is private. Then they make aspects of their blockchain history unprivate, which then merges with the global blockchain (or perhaps there are multiple layers of blockchain nesting). But each transaction would have a different key, so no one user could be traced. Yet you need potentially a way to still trace this, so the user themselves would have the transaction history accessible to themselves and whoever they share it with.


texts: Why implement *Wallet* at library level?

texts:
Using bitcoin-qt, and we need to create Wallet to handle our account (Private + Public Keys).
But I really don't know why we are forcing this to everyone at library level.
I can't find a simple way to handle multiple wallets with one single instance of bitcoin-qt.
Can I have multiple addresses from different users added to the same wallet? My spider sense tell me NO. It is like we are sharing the same wallet with stranger in real life.


texts: Is an attack on a local bitcoind via an img or embedded flash viable?

texts:
In this thread on the Bitcoin forums it was suggested that a local attack on bitcoind might be possible through malformed img tags or (more likely in my opinion) through embedded flash. This also brings up the possibility of exploitation via Java et al.

Unfortunately I don't know enough about flash to determine whether it's prevented from connecting to a listening client on localhost. I would assume it's sandboxed away from anything else on the local network, but I honestly don't know if they've bothered to restrict access to localhost.


texts: How to check Bitcoind block chain download progress level without blockchain explorer?

texts:
so my problem isn't with bitcoin particularly but with a dying altcoin, I have the same problem as here.
But can't use a blockchain explorer site, since there doesn't exist one.
Is there any way to query this number from a node?


texts: The Bitcoin exchange MtGox has stated in this press release that "transaction malleability" caused them to stop sending bitcoins. A recent question asked if it really is an issue. But what is transaction malleability in the first place?


texts: What is the difference between BTC/LTC & LTC/BTC markets?

texts:
I am little bit confused about markets, In cryptsy there is a market for LTC/BTC in which we can buy or sell LTC using BTC

My questions are,

Is both LTC/BTC & BTC/LTC are the same?
I have tried cryptocoincharts, but seems to have incorrect values, Any valid market api call to fetch the BTC/LTC market values?


texts:
I have setup WooCommerce and BTCpayserver in Google cloud, and synced. Test to buy with BTC seems to work.

Adding Lightning fails:
I modified in BTCpay Lightning nodes in the Store management
"clicking here" added the connection string:

Type=clightning;server=unix://etc/lightning_bitcoin/lightning-rpc

I submit and came back to test connection, it fails:

Error: Error while connecting to the lightning node via 34.73.111.47:9735 (The operation was canceled.)operation was canceled.)

I used during setup the following Exports:

 export BTCPAY_HOST="btcpay.elmit.com"
 export NBITCOIN_NETWORK="mainnet"
 export BTCPAYGEN_CRYPTO1="btc"
 export BTCPAYGEN_REVERSEPROXY="nginx"
 export BTCPAYGEN_LIGHTNING="clightning"
 export BTCPAYGEN_ADDITIONAL_FRAGMENTS="opt-save-storage-xs;opt-save-memory"
 export BTCPAYGEN_ADDITIONAL_FRAGMENTS="$BTCPAYGEN_ADDITIONAL_FRAGMENTS;opt-add-woocommerce"
 export WOOCOMMERCE_HOST="store.elmit.com"

Did I miss something?


texts: Why are Bitcoin prices so different between different markets?

texts:
Sorry if this is a basic question, I'm new to this stuff.

Currently, according to cryptocoincharts.info, Bitcoins are trading at $1050 on BTC-E but $1228 on Mt. Gox. How is this possible? What would cause such a large price discrepancy? Shouldn't it be possible to capitalize on this difference by buying at BTC-E and selling at Mt. Gox, and if so shouldn't that tend to equalize the trading prices?


texts: 0/confirmation race attack double spend transactions

texts:
I am developing a point of sale bitcoin app, which should accept "fast" transactions (~30 sec for merchant to accept). I researched double spending questions here already, but it is still unclear to me, what happens within the time frame before a transaction is actually included into a block.

Considering the case of a double spend attempt, where an attacker needs to pay to a merchant. The attacker creates and propagates a respective transaction A into the the bitcoin network. Transaction A is added to the main memory of mining nodes and is "waiting" for inclusion into one of the next blocks. The merchant is informed of the propagation of transaction A by the nodes he is connected to. Before transaction A is actually included in a block, the attacker creates and propagates another transaction B, which has the same inputs as A (double spend).

What happens if a miner (which has transaction A in his main memory) gets the conflicting transaction B?
Can a merchant be sure, that transaction A will be confirmed, if it is propagated successfully to let's say all or most miners?
Would a miner throw away transaction A and include B, if B has higher transaction fees, a smaller size in bytes, or of other attribute?


texts: What is the safest physical to store a private key only to be accessed after death?

texts:
Assume that my friend would like to encrypt his Bitcoin private key(s) and safely store them in a secret location. This located would only be identified to heirs after death in his will. Should he put the key:

In a safety deposit box
Buried in a weatherrpoof container somewhere on my property?
In the possession of my attorney?
Somewhere else

Please answer the same question above for my encryption key which I would of course store separately.

As an alternative would a mult-sig solution be helpful? If so how would you design it?


texts: How do I set up a fee for my p2pool node?

texts:
I'm running a p2pool node for dogecoin.

Since running the node costs me some money, I set up a small fee with

./run_p2pool.py --give-author 0 --net dogecoin -f 0.5 -a DSomeDogeAddressIOwn DOGEUSER DOGEPW

but I don't seem to get any fees.
The local hashrate is around 10 MH/s, so I should get at least a few dogecoins.

Basically I used this setup: http://doges.org/index.php/topic,5586.0.html

It is running on an Ubuntu 12.04 Server, everything else works.
When I use the webinterface, "http://example.com:22550/fee" displays '0.5' as expected

Am I missing something?


texts:
I'm wondering about switching coins while solo mining?

Does switching before I block is mined effect the odds of getting a block reward, or is it always essentially chance??
For example, if I mine for 30 minutes on Feathercoin, then jump to Litecoin, when I come back to Feathercoin will there be any accumulated value in the wallet?

Am I ever starting over, or is it always chance?

By the way, I'm using a node stratum pool, so it's direct connect to the wallet.


texts: If the blockchain records all transactions, how does losing your wallet imply that you lose your Bitcoin?

texts:
My understanding is that the blockchain records every transaction that has ever occurred, and that, when we say there are x amount of coins at address y, what we really mean is that the blockchain records transactions in which the difference between the total amount of Bitcoin going to that address and leaving that address is x.  In other words, it doesn't store the amount of Bitcoin at an address per se, but instead determines this by looking at transactions.

If my understanding of this is correct, then I don't understand how you are at risk of losing your Bitcoin if, for example, your hard drive crashes.  The blockchain would still be able to tell how much coin was at that address, so all you would need to be able to do is prove that that address belonged to you.

If the problem is that the address goes away with the client and (most likely) the user didn't have their address memorized, then why not just add the ability to access the same address with more than one client?  This way, if, for example, they lost their client on their desktop at home, they could still look up their address on their client at work, on their laptop, etc, and be able to recover the 'lost' coin.


texts: Why can't someone build a custom computer and win the reward for a few days?

texts:
I've been reading about mining, and that to get the reward it basically comes down to brute force. The difficulty of this brute force being adjusted every 2016 blocks.

I also understand that some hardware are better at brute force than others.

So, if I were to tinker in my garage an amazing mining rig, connecting together many ALUs or whatever (sorry I'm not a hardware guy) to give myself a significant advantage - would this work?

I'm not saying it would work forever, but would it work until someone built an even better machine, or until the difficulty self adjusts again?

I assume it's not the case since it would happen a lot. But seeing how people are racing to build the top mining rig, I feel like there is some degree of truth?


texts: Why are Bitcoin addresses starting with 1s or 1S so rare?

texts:
I've generated 10000-50000 key pairs using Chrome Bit Kit app or www.bitaddress.org and have noticed the scarcity of public keys which begin with 1S and/or 1s.

Why is this the case?


texts:
What I have learned is that state is an abstract thing and is maintained by the node locally and the state of the current blockchain can be reached by starting all the way from the genesis block and updating the state to the current state. So the state keeps adding utxos.

Does the state keep track of only the UTXOs which are unspent or the state keeps track of both the spent and the unspent utxos. What I think is ,they should be removed from the memory pool. Also what I think is that the memory pool is nothing else but the state of the blockchain.

Please clarify my confusions. Thanks


texts: Port 8333 closed, fwd on Router OK, firewall port open, full-node not reachable

texts:
I have set up my bitcoin/lnd full node and found out that port 8333 is closed.

When checking using https://bitnodes.io it tells me it's down

I've checked the router config and port 8333 is forwarded to the IP of the node.

If I scan or use telnet to connect locally to my node, it seems to be blocked.

Also ufw has been checked and sudo ufw allow 8333/tcp has been added.

As well sudo netstat -tunlp tells me that the port is in listen state.

Now, I'm kind of stuck and looking for help.

Many thanks in advance for a reply and stay healthy.


texts: Any privacy considerations regarding allowing inbound connections for a Tor full node?

texts:
I wanted to know if there's any privacy considerations to take into account when opening the bitcoin ports on the router for a bitcoin node.

I'm using -onlynet=onion in the bitcoin.conf file and I did not modify any tor config file.

I also wonder if a remote port scan can detect I have a bitcoin port open in the router and whether changing to a random port would help privacy. thanks.


texts: Unstuck a unconfirmed transaction with Coinomi

texts: I sent a Bitcoin transaction with Coinomi android wallet. I selected the default recommended fee option. However, later I saw that it set only 0.01 USD transaction fee. My transaction is stuck in an unconfirmed state. I need the transaction to go through, it's lot of Bitcoins and I need them now. What is a step by step guide to either cancel the transaction or make it through? The address I'm using is BIP 84 Native Segwit. I tried uninstalling and reinstalling Coinomi, but that doesn't change anything after I re-enter the master seed. I didn't have luck with other wallets either. I read about double spending, but I'm not sure how to execute it. Any help?


texts: How do you check the validity of a signature while only having the hash of the public key

texts: So far as I understand it, a Bitcoin transaction is signed with a private key and the rest of the network can then use the public key to verify that it is indeed signed by the right private key. However, as public keys are hashed, how do I use them to verify the private key?


texts: Need help to understand where bitcoin transaction has gone

texts:
I am new with bitcoin and I need some help from experienced members.

I have a server with bitcoin core where we accept some payments and use bitcoin core as mercant.

The problem is that we have got an incoming transaction which we didn't see in our wallet.

Here is the hash of the transaction: 460c0dc70ef52fd66142d1798a1735b4613c9ffec478efe5997d1ede0d16f28a

In our bitcoin core through the bitcoin-cli command line I can see the following:

bitcoin-cli listtransactions 1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ
[
  {
    "account": "1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ",
    "address": "1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ",
    "category": "receive",
    "amount": 7.02278014,
    "label": "1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ",
    "vout": 1,
    "confirmations": 128,
    "blockhash": "000000000000000002ef00cf04d1a6197cd07d5b7826d2dc8cd8a86fd41d578f",
    "blockindex": 425,
    "blocktime": 1463303078,
    "txid": "460c0dc70ef52fd66142d1798a1735b4613c9ffec478efe5997d1ede0d16f28a",
    "walletconflicts": [
    ],
    "time": 1463299775,
    "timereceived": 1463299775,
    "bip125-replaceable": "no"
  },
  {
    "account": "1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ",
    "category": "move",
    "time": 1463303102,
    "amount": -0.00007000,
    "otheraccount": "1M1LTHjc1JAcVfCoyhSkoP1VH8B9RLY8tg",
    "comment": "merchant fee"
  },
  {
    "account": "1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ",
    "category": "move",
    "time": 1463303102,
    "amount": -7.02278014,
    "otheraccount": "1LBa3bAVF5RSfnFnm3sX1Zm5R8WU1J8xnK",
    "comment": "invoice forward"
  }
]

As I see funds were successfully moved to 1LBa3bAVF5RSfnFnm3sX1Zm5R8WU1J8xnK, which is correct, but on blockchain, for example, if I go here
https://blockchain.info/address/1K7Pci1re92vQuTSXbirmvQsmYMpXHQWbQ
I see that were sent to another address!

How to understand that, and how to find where these bitcoins have gone?

Any help will be appreciated, thank you very much!


texts: Copay wallet no longer available on the Google Play store

texts: This URL where the Copay wallet used to be now just shows "We're sorry, the requested URL was not found on this server." Why was it removed? Was there a security issue? Is this going to affect the app installed on my phone?


texts: Are transactions verified in chronological order?

texts:
I've seen that blocks include timestamps which are updated "Every few seconds", but who updates the timestamps, and are the timestamps used to verify transactions in chronological order?

If a block with a certain timestamp is added to the blockchain, will any block with an earlier timestamp be rejected?

How is the timestamp used by the protocol?


texts:
Let's say that I am using 2 of 3 multisig. I know how to use signrawtransaction and sendrawtransaction to send the funds if at least 2 of the parties have agreed on the transaction, but I don't know how to revoke it and send the funds back to the first person.

How do I do that?


texts: Unknown command name and packet magic for bitcoin packets at the start of blockchain transactions

texts:
Recently I captured a part of blockchain when my bitcoin wallet started to syncing for the first time. I analyze about 10 Gb of traffic which was for primary transactions of bitcoin.
wireshark can detect them as bitcoin traffic but these packets don't have a valid command name and a valid packet magic. according to this link:

https://en.bitcoin.it/wiki/Protocol_documentation#Network_address

all magic values are 0xD9B4BEF9, 0xDAB5BFFA, 0x0709110B and 0xFEB4BEF9.

my first question is why a lot of packets at the start of blockchain don't have a valid magic packet and valid command name, and how wireshark can detect these packets as bitcoin while they don't have a valid header?


texts: Confused about UTXO management and consolidation

texts:
I have a few questions regarding utxo management and consolidation. I know that the more UTXO's you have, the heavier your transaction will be, the more fees you'll have to pay.
The things I don't understand:

How can you effectively avoid that? Let's say I generate a new address every time I self-custody bitcoin, it won't solve the problem, does it? When I'll want to send either the max balance or let's say a rather large amount that needs a lot of utxo's to be complete, the full tx's will be heavy no matter what, correct? So using the same address for cold storage (i.e just a receiving address) or using a new one every time doesn't change a thing?
If a wallet has coin control, does it really matter to do utxo management?
Let's say I have a single address with 100 UTXO associated to it. I want to consolidate everything. I first generate a new address on my wallet, test that address by sending a small amount (from an exchange let's say). If everything seems correct, I can then use the send max feature of my wallet to that address (everything being under the same seed)? Even though it will effectively also send the utxo I just used for testing the validity of the address back to itself?

I think that's all my questions, thanks.


texts: How do exchange services distinguish who sent to them?

texts:
I know some altcoins have features that allow senders to attach messages to transactions and using those features, exchange services distinguish the sender.
However, I don't know if there's such a function in Bitcoin. How can exchanges tell who paid them without such a feature?


texts: Question about Electrum wallet file on USB Drive (MacOS)

texts:
I have been using a hot wallet (Electrum) for quite some time.
Now, I don't want to lose my BTC, so I have decided to transfer the wallet file from the directory where it is located to my USB Drive. I don't know why MacOS keeps changing my wallet file (with no extension) to a Unix executable when I transfer it to my USB Drive.
Thank you all for your insight!


texts: OP_CHECKSIG: reasoning behind construction of message to be signed

texts:
I've closely studied the deservedly famous OP_CHECKSIG explanation found here, including the diagram found here. That explanation details how to construct the message that is signed via ECDSA, producing the digital signature for SigScript. All good.

By way of summary, the aforementioned message is an amalgamation of the new transaction under construction (with its ScriptSigs nulled out) and the scriptPubKey from the sourcing transaction output. For clarity, the "sourcing transaction output" is the one identified in the transaction input under construction by its Transaction Hash field and its Output Index field. All good.

MY QUESTION: in the new transaction under construction, its Transaction Hash field already "fingerprints" the sourcing transaction output. Why go to the effort of inserting the aforementioned scriptPubKey from the sourcing transaction output into the message? That seems redundant, given that the hash digest in the Transaction Hash field fingerprints the entire sourcing transaction.

I ask this question in order to more thoroughly understand the logic behind the intricate construction of the message that is signed via ECDSA.


texts: Solar Flare wipes all hard drives... What happens?

texts:
Imagine, for a moment, that a massive solar flare wipes out all hard drives on planet Earth.  All hard drives are wiped clean and with them all records of the Bitcoin blockchain.

Would we be able to recover?  Is there some alternate backup of the blockchain?  Do we hope that at least one computer is protected beneath ground?

I assume everyone's personal wallets would be lost unless they used paper wallets.  Certainly a big blow to the Bitcoin community.


texts:
I would like to do some solo mining of litecoin on OSX.  I realize the probability is low that i will hit it. but i like the idea of the lottery.  I have a miner setup (cgminer) and i have successfully connected to a pool.  I have found lots of guides that explain how to do this on Windows like:
https://bitcointalk.org/index.php?PHPSESSID=3rq912e407g04cjq8ehdhnk457&topic=83371.0

But what all these guides tell you to do is edit litecoin.conf and then restart litecoin-qt.  But does this still apply to OSX? I don't see a litecoin.conf anywhere.  I have looked in
Library/Application Support/Litecoin
Is it still litecoin.conf in OSX? or is it a different file?


texts: Can Bitcoin Days Destroyed be a better resolution mechanism for competing blocks?

texts:
I've been looking at selfish mining and empty blocks.  In all cases, the selfish miner profits by keeping block solutions private until their value to his own pool is maximized, rather than releasing them ASAP which is the honest way to do it.

If the protocol were changed to make holding back a block far riskier than it is currently, I think this would go a long way to solving the problem presented by selfish mining.  A selfish pool holds a solved block until someone else solves a block at the same height.  The selfish pool then releases its pre-solved block (having had time to privately seed the global network so that as many honest miners as possible will see the selfish block first) to orphan the honest miner's block.  Currently, the risk is that enough honest miners might choose the honest block with the result that the selfish miner loses both the reward for having solved it first and the advantage of being one block ahead. The papers on selfish mining show that this risk is not great enough to prevent selfish mining.

The protocol currently expects a miner to use the first block that adds to the chain.  If this rule (actually a suggestion) were changed to expect a miner to use the block that destroys the most bitcoin days, selfish miners would risk far more by holding back their solutions.  It would still be relatively easy for a selfish miner who has gotten ahead to exploit his position by saving the solution until it can be used (if it destroys more bitcoin days) to orphan someone else's solution, but the risk that the other solution might destroy more bitcoin days would be significant.  Even if the selfish miner seeded his solution with his own very old UTXOs, he would be wasting some of his ammunition (bitcoin days).

Additionally, the rule that a miner use the first seen block or any other rule to resolve conflicts when two blocks show up as possible extensions to the current chain is not enforceable.  So perhaps what is needed is not for the protocol to change, but for miners (who would like to prevent the selfish mining attack) trying to decide between two new block heads to use bitcoin days destroyed to decide.  Publishing this idea, however, is not warranted until it has been criticized for flaws.

So have at it!


texts:
Is it possible using bitcoind JSON-RPC API to receive funds from someone and send it immediately to another third-party address? I do not want to wait for 1 confirmation.

getbalance with minconf=0 shows I have 0.01 BTC, but when I do sentfrom with minconf=0, I get Insufficient funds error.


texts: Is Ripple's Contract language intended to be Turing complete or sub-Turing complete ?

texts:
The wiki seems to imply Turing-completeness because no restrictions on jumps are specified here https://ripple.com/wiki/Contracts#Foundational_Ops.

Which is it and what (if any) is the actual intention ?

Cheers ...


texts: Is there a way to get the memory pool in order of newest first?

texts:
I'm trying to list out the results of getrawmempool by newest transactions first.

Here's what I've got:

getrawmempool returns the memory pool in order of transaction hash, so I'm using PHP to sort it:

<?php
// Get an array of the memory pool transactions
$getrawmempool = $bitcoin->getrawmempool(true); // true = verbose

// Create a new array of "txid" => "time" (just so I can sort it)
foreach (array_keys($getrawmempool) as $txid) {
     $mempool[$tx] = $getrawmempool[$txid]['time'];
}

// Sort the new array
arsort($mempool);

// Print results
print_r($mempool);
?>

Now, this isn't terribly slow, but sorting 10,000+ array values isn't terribly snappy.

Questions:

Is there a way of getting the mempool in order of newest first from bitcoin-cli?
If not, is there a faster/better way of sorting the returned results?

I'd like to play around with all the mempool transactions using PHP. So if I can get the mempool transactions in order along with all the verbose information about each one, that would be handy.


texts: How does this simple script use the OP_CHECKSIG opcode?

texts:
I have this Script P2PKH

<A Signature> <A Public Key>
OP_DUP OP_HASH160 <A Public Key Hash> OP_EQUALVERIFY OP_CHECKSIG

The bitcoin.org documentation say this

  The entire transaction's outputs, inputs, and script (from the most recently-executed OP_CODESEPARATOR to the end) are hashed. The signature used by OP_CHECKSIG must be a valid signature for this hash and public key. If it is, 1 is returned, 0 otherwise.

Now I want to understand how the code is running inside the stack and how the OP_CHECKSIG work.

My question comes from the fact, why use another operator (OP_CHECKSIG) if is used the operator OP_EQUALVERIFY to does control ?

But I have another question on OP_DUP, the documentation say this

  Duplicates the top stack item.

Why when the bitcoin run the script need to duplicate the items inside the stack?

to close, exist other documentation on Bitcoin Script language?


texts:
I have google a lot, there exists little information, confused with the code comments

Retrieve the range of blocks that may have been only partially written. If the database is in a consistent state, the result is the empty vector. Otherwise, a two-element vector is returned consisting of the new and the old block hash, in that order.

why there exists old & new block, their function?


texts: timestamp different block explorers are not the same

texts:
I'm kind of confused why the timestamp of a block is different when checking different block explorers. I think normally this is the time the block was found, no?
So, when I check a transaction in blockchain.info, it has a different timestamp then blockexplorer.com. The difference in this case in 1 hr and 5 minutes. Any ideas why?


texts: Can a bitcoin transaction be reversed from the receiving end?

texts:
I know this seems like a duplicate of the question 'Can a bitcoin transaction be reversed?' but none of the answers there were explicit enough as they all seemed to assume reversal triggered from the sending side.

I guess a secondary part of my question is 'What would happen if a merchant just sent the funds back to any one of the input addresses that was used in the original transaction?' Would the  money be effectively returned to my control?


texts:
Pardon my Ignorance but can somebody explain the basics

Of how trading (Bid Buy/Bid Sell) works of the common exchanges

www.mtgox.com
www.btc-e.com

Aslo some of the common ways people or conditions suppress or raise the price of LTC & BTC

Thanks In Advance


texts: Help with bitocin.conf - how to configure a testnet full node in a safe way?

texts:
The general purpose here is just to have a close interaction with the bitcoin network for exploring reasons and apply some knowledge I have gained through reading here and there.

I am not expert! So, I am afraid to mess up and enable something in the bitcoin.conf, I am not fully aware of it consequences. Especially that my personal laptop (running Ubuntu) is the only resources I have right now for a full-node setup.

My initial goals are to:
 - run a testnet full node to experiment with the avaliable limited resources
   (4 RAM, 50 gigs free storage and metered internet connection)
 - secure my fullnode in the network (I setup the ufw firewall and created a
   new separate account no idea though if I must do more in terms of the
   account permissions. It is a standard one)

The only examples, I found are:
1) a very general file in github: https://github.com/bitcoin/bitcoin/blob/master/contrib/debian/examples/bitcoin.conf

2) This one I found in the bitcore.io documentation: https://bitcore.io/guides/wallet-service

I tried to edit it a little bit to serve my goal, I hope you can have a look into and I am more than happy to hear your recommendations. Maybe, I have to put it in another format, since it is meant to be a conf file for the bitcore implementation. I embedded some comments and questions in the file

Here it is:

{
      "network": "testnet",
      "port": 18333,
      "https": true,
# must I create my keys myself? Is it the pathway important here?
  "httpsOptions": {
     "key": "some-place-safe/key.nopass.pem",
     "cert": "some-place-safe/cert.pem"   },
  "servicesConfig": {
     "bitcore-wallet-service": {
 # is it ok to use this port?
       "bwsPort": 3232
     },
     "bitcoind": {
       "datadir": "/home/user/.bitcore/data"
       "exec": "/home/user/bitcoin/src/bitcoind"
     }
 },
      "services": [
         "bitcoind",
         "bitcore-wallet-service",
        "insight-api",
        "web"   ]
}

Probably, other stuff must be added, at the moment I am still lost and trying to navigate through the first conf file

Thanks a lot in advance!


texts: Is JavaScript wallet generator available at bitaddress.org relatively secure?

texts:
I wonder if it's safe to use JavaScript generator available at bitaddress.org.
Even if I'll generate it offline, how can I know if the algorithm is not using any pre-computed / pre-planned way of generating the addresses?


texts:
I discovered that there are some questions that discuss finer points of the Open Transactions Software, however the project itself could use a proper definition.

Please explain concisely what the Open Transactions is:
How does Open Transactions work, what problems does it solve and how does money get into the open transactions network?


texts:
I have created a testnet wallet on testnet.blockchain.info and added some testnet bitcoins to it.

I want to test the payment APIs so I am following the documentation on how to Generate a receive address. Yet I do not see a way or an URI to register a testnet receive address.

I tried to use it as is and I've put my testnet xpub in the query but I get this error:

{
    "message": "Invalid xpub format",
    "description": "Ensure you provide an xpub key, rather than an address"
}

Anyone had success using blockchain's payment APIs with testnet before?


texts: What parameters are used to calculate the challenge string during bitcoin mining (blockchain creation)?

texts:
How is the challenge string computed mathematically? What's preventing some node on the bitcoin network from broadcasting a challenge + proof to other nodes as it's own when it received it from some other node?

A parallel to this question would be, how do a node, on receiving, the challenge + proof, authenticate the node which produced this combination?

I tried looking this up elsewhere, but the details of the challenge string calculation seems to be abstracted away in most tutorials.

Thanks in advance!


texts: What keeps bitcoins mined in testnet from being used in mainnet?

texts: I've been reading up on how transactions actually work, but I'm not sure I understand how testnet bitcoins are kept from being spent on mainnet. My best understanding is that coins are actually references to transactions on the chain, so referencing a testnet transaction on the mainnet chain would not work. Is this correct?


texts: why is my p2sh raw transaction not being mined or erroring ERROR: 64: NON-MANDATORY-SCRIPT-VERIFY-FLAG (EXTRA ITEMS LEFT ON STACK AFTER EXECUTION?

texts:
I created this 2-of-2 multi-signature address for testnet following the instructions on the book Programming Bitcoin. I tried to spend the funds in this address following the standard forms (OP_HASH160 1060f2fd6058cd100fe4e485455badf453bd63e1 OP_EQUAL) Everything passes the verification tests in the code, but when I try to broadcast my transaction it never gets mined or it is rejected with ERROR: 64: NON-MANDATORY-SCRIPT-VERIFY-FLAG (EXTRA ITEMS LEFT ON STACK AFTER EXECUTION).

here is my raw transaction:

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

I have only one input, and I am spending it all. The commands for the script signature for this input are built following the standard (OP_0, Sig1, Sig2, Redeem_script):

0,

3045022100e9a2b73ff95e3395034e910d5d69dd3e18e12a28e9dacfd5f3b2894afd5fbf3f022035b50d48506932020fcea1781a0c58e9011918bd2a9cbbb5693027035ca9502b01,

3045022100f7621bb014d53d8a97c0b5605317dd4a92b53e03dd22e71b1db85c12e92218ff02204b77ff2a5bc9f7921d8a17d36d04ca29cbe25b2061f7c2f5e227e449ba614ee501,

47522103e07f96e5ba598431c0c994493a4ae988c9854c171d5d4bb140db0a27a4c853e421031b63f964d8c65d1d1136dcfe5033dedea88c2d411934ea48c9708410be84e5ee52ae

which are encoded in the transactions as:

dc00483045022100e9a2b73ff95e3395034e910d5d69dd3e18e12a28e9dacfd5f3b2894afd5fbf3f022035b50d48506932020fcea1781a0c58e9011918bd2a9cbbb5693027035ca9502b01483045022100f7621bb014d53d8a97c0b5605317dd4a92b53e03dd22e71b1db85c12e92218ff02204b77ff2a5bc9f7921d8a17d36d04ca29cbe25b2061f7c2f5e227e449ba614ee5014847522103e07f96e5ba598431c0c994493a4ae988c9854c171d5d4bb140db0a27a4c853e421031b63f964d8c65d1d1136dcfe5033dedea88c2d411934ea48c9708410be84e5ee52ae

My redeem script follows the standard (OP_M, pubkey1, pubkey2, OP_N, OP_CHECKMULTISIG):

OP_2 03e07f96e5ba598431c0c994493a4ae988c9854c171d5d4bb140db0a27a4c853e4 031b63f964d8c65d1d1136dcfe5033dedea88c2d411934ea48c9708410be84e5ee OP_2 OP_CHECKMULTISIG

The input I am trying to spend is under the transaction:

9f6e65900ca76e8351b7babc6bbc2e5b0b2ded99e4e6f5b1ec74c2a190abf31a

By looking at the error, it seems like my public_key_script and my redeem_script are not consuming all the data in the stack, but I have checked everything, and I can't find what it is. HELP!

Ps: I do not think this is a relevant detail, but the input of the transaction was sent by one of the two public keys that generated the multi-signature address. Just trying to be thorough.


texts: Backup of a bitcoind wallet using the extended private masterkey only

texts:
If I understand correctly, bitcoind makes use of a extended private masterkey in order to deterministically generate private/public keys for a wallet.

Using the dumpwallet command, I'm able to get access to this extended private masterkey.

My questions:

1) If I only backup that extended private masterkey, would I be able to recreate the wallet entirely in case my application crashes? Or do I really need to backup the wallet file itself? (Let's say I do not import addresses that were not generated by bitcoind itself.)

2) I heard that changing the passphrase of a wallet would change the extended private masterkey... Is that true?

3) If #2 is true, can I simply backup all generated extended private masterkeys (every time I change the passphrase) to be able to recreate the wallet entirely using those multiple extended private masterkeys? What would be the command to run to recreate the wallet from more than one extended private masterkeys?


texts: Who decides whether a submitted share leads to a valid block or not?

texts:
If a share does not lead to a valid block they would not require to be sent to the server?
Or is the only purpose of the share sent to the server to show that the client did some work?


texts: Balance between minimum transaction fee and time using Electrum 3

texts:
Yesterday I made my first Bitcoin transaction using Electrum and I was able to configure the fees I was going to pay. As it was a non-urgent transfer I selected the minimum fee Electrum allowed me: "Within 25 blocks", the lowest sat./byte available from the slide bar.

If the transaction was supposed to be included in the next 25 blocks, I thought it will take around 250 minutes (~4hours) to be processed. But I don't know why, after 2hours the transaction already had 6 confirmations.

This minimum fee ended up being 0.0008 BTC (~10 € as the time of writing, which was ~14% of the sent amount).

Why did the transaction went so fast if the fee was for 25 blocks?
As it was a non-urgent transaction, couldn't I have selected a smaller fee in any way? I couldn't find a way to pay smaller fee in Electrum 3 --I could have waited for 24h with no problem to avoid this high fee.
Does this means that I paid much more for the fee than I could have paid, given the non-urgent requisition of my transfer?


texts: Help with understanding Semaphore grants in OpenNetworkConnection

texts:
I am new to concurrent programming. Can any expert throw some light on the semaphore grant that one requires before acquiring a network connection ?

bool OpenNetworkConnection(const CAddress& addrConnect, CSemaphoreGrant *grantOutbound, const char *pszDest, bool fOneShot)

I also notice that while we give onetry in addnode command of RPC client, the grant is taken as NULL.


texts: How would multiple people send in one transaction?

texts:
Is it possible to have multiple inputs, from different people?

How would this be set up?


texts: In ScriptSig, which form of the public key is considered canonical?

texts:
In the standard pay-to-pubKeyHash scriptSig, which form of the public key should be used. My understanding is that both the compressed (33 bytes) and the expanded (64 bytes) are both valid.

Is there any of these two that is considered "standard"? Will the reference implementation propagate transactions containing either form, or will it withhold one?

IMO, I should use the compressed version since it will result in smaller transactions.


texts: What is the cost of resolving a Lightning channel breach?

texts: If someone breaches a Lightning channel (aka tries to spend more than he is allowed to), the other party has to intervene and prove that the coins actually belong to them. This process happens on-chain. How large would such a transaction be? Is it proportional to the number of transactions that happened while the channel was open?


texts: Can someone provide a list of mining pools like eligius who will accept non standard transactions directly and mine them?


texts: Where are the blocks in the blockchain stored?

texts: I understand that every transaction of bitcoin is stored in a "block" which is then added to the "blockchain". I realize that this is data of some sort that must have a physical location. Where is that location(s)? Where is the data of the blockchain stored?


texts: Method of spending LTC Litecoin from a paper cold wallet?

texts: I know mycellium has a feature for BTC where you can spend partial amounts from a Bitcoin cold paper wallet. Is there something like this for a LTC Litecoin cold paper wallet? I just want to spend a few ltc, but not sweep the entire paper wallet.


texts: Why does Antpool mine so many empty blocks?

texts:
AntPool, the largest mining pool mines a lot of empty blocks (quick stat over the last 100 blocks they mined at time of writing shows 20% <10kB).

While I understand that sometimes it is useful to mine an empty block when one has not had time yet to validate all transactions in the previous block. This validation should be very quick compared to the average 10min block time (validating a full block of like 2000 transactions should not take more than a few seconds on a modern PC, no?).
So, why the hell is Antpool mining so many empty blocks???

Just to compare, the same stat for the 2nd largest pool, F2Pool, gives only 4% blocks <100kB and 0% <10kB.

EDIT: I pulled out some more stats over the last 500 transactions as of 16/12/2006 11:25 CET
- 18 blocks < 5kB (3.6%)
- AntPool mined 98 blocks, out of which 16 < 5kB (16.3%) covering almost 90% of empty blocks
- Empty blocks came on average 6.6min after the last block so yes faster than the overall average 10mins but still plenty of time to include transactions
- Only 16% of these 18 were very quick empty blocks <1min


texts: Transferring partial BTC between wallets if I know both private keys

texts: Is there a way to transfer/import partial amounts of BTC from one wallet to another off the chain in order to avoid transaction fees? I assume this is how services like Coinbase get around letting you transfer funds from your Coinbase to GDAX wallet without any transaction fee since they know both private keys. Is this possible? If so, how would this be done with something like bitcoinjs-lib?


texts: How to calculate economic security for bitcoin proof of work?

texts:
Is this the correct way to calculate security for bitcoin proof of work?
https://twitter.com/drakefjustin/status/1356918733441294336
If a government or group of few rich people or organizations create a token, hold most of the tokens and stake it, price of this token and few people holding this token makes the system secure?
What are other differences in proof of work and proof of stake?


texts: What happens with the bitcoin locked in the payment channel if both sides lose the backup?

texts: If none of the sides closes the channel, is the coin locked up forever?


texts:
I was hoping someone would be able to help please?!!

I backed up my litecoin core wallet and neo wallet to my usb- today i took that usb out with me since I had other stuff on it too and needed to use it. I lost the usb like an idiot- is there a way to change the seed for my neo wallet and address for litecoin wallet so if someone finds my usb, they can't get into the wallets. I know I have backed them up on the USB but I am not sure what other info I have left on there.

I know I am an idiot- please help this idiot!!


texts: Bitcoin URGENTLY Need Blocks Files - Download them from some Website

texts: I have been doing this synchronization procedure (first time) in bitcoin-qt for over 85 hours and it only came to 31 Weeks Behind. Withdrawed from localbitcoins like 95 hours ago and obviously this balance isn't yet seen. I have come to the step where I cannot wait anymore. I only have 512 dram and it is taking my whole system. Also cannot leave pc runned 24/7 anymore. It would be amazing if someone could please upload to some fast legitimate file sharing website like rapidshare.com the blocks files - remaining ones. Once again I repeat i am at 31 Weeks Behind. Or please if you could at least provide me the downloading link if you already shared blocks files yesterday with anyone else or maximum two days ago. I really need that procedure finished please and would owe you for a lifetime for such files so I can just save them. Would be much faster. I cannot use torrents, even if those files are updated enough and already there - torrents aren't safe and could be full of malware.


texts: Will skipping nonce enchance mining performance given there's more resourceful miner

texts:
As most miner program start with 0 nonce and increment from there, given there are many resourceful miners who will also compete for the same desirable nonce:

Everyone is mining at [0 ~ LARGE_RANGE] (lower range)

I mine at [LARGE_RANGE + 1 ~ MAX_RANGE] (upper range)

Scenario 1: Other people found the desirable nonce at the lower range, they do it way quicker than I do even if I were to mine on the same range.

Scenario 2: The desirable nonce is at my range and I found it first(before others found it since I skipped the lower range)

Is this a possible way to improve my mining performance?


texts: Multibit balance does not match blockchain balance. Weird extra bitcoins appear. Now the are gone plus some?

texts:
So, really weird. Went to send some bitcoins to another of my wallets and all went as expected. I sent 1.013 BTC from a balance of about 3.01254367 BTC. My girlfriend then went to make a withdrawal. She said the balance was just over 4 BTC before the withdrawal which it couldn't have been because of my last transaction. It should have been just over 2 BTC. She said she sent 4 BTC leaving about 0.5 BTC in wallet. The transaction stuck, that was when I got involved to sort it all out!

I reset the blockchain and transactions on multibit and now the balance is 0.97 which doesn't seem to match up with anything? The transaction has shown up on the blockchain at all but I'm down by about 1 BTC.


texts: Open source ASIC design plans in Hardware Description Language (HDL) format?

texts: Are there any freely-available ("open source") ASIC design plans in, e.g., HDL or AHDL format(s)?


texts:
When I'm trying to create a wallet in react app using the following code:

const seed = bip39.mnemonicToSeed(mnemonic);
const master = bitcoin.HDNode.fromSeedBuffer(seed, "testnet");

I got error: Expected property "0" of type ECPair, got p


texts:
Every transaction takes unspent outputs as inputs and creates new outputs. The creator of the transaction uses his private key to sign the transaction and nodes validate that transaction by using the public key of the creator.

But how excactly are transactions formated? I have seen this on the bitcoin wiki:

Input:
Previous tx: f5d8ee39a430901c91a5917b9f2dc19d6d1a0e9cea205b009ca73dd04470b9a6
Index: 0
scriptSig: 304502206e21798a42fae0e854281abd38bacd1aeed3ee3738d9e1446618c4571d10
90db022100e2ac980643b0b82c0e88ffdfec6b64e3e6ba35e7ba5fdd7d5d6cc8d25c6b241501

Output:
Value: 5000000000
scriptPubKey: OP_DUP OP_HASH160 404371705fa9bd789a2fcd52d2c580b65d35549d
OP_EQUALVERIFY OP_CHECKSIG

If we use this transaction as an example, how do we take the data from this and format it into a RAW signed transaction that I could send straight into the network without the need of a wallet?

Also, after creating the signed RAW transaction, is it just hashed by SHA256 to create its hash ID or does creating the ID consist of other steps?

Lastly, what is scriptSig? I don't quiet understand scripts in general so if someone could give me a brief explanation of that as well I'd be grateful

Thanks in advance!

Fihdi


texts: Can you replicate a wallet somewhere else

texts: If I used my 12 seed words in another wallet provider that used the 12 word backup protocal, whether hard hot or mobile, would that then replicate my wallet?


texts:
I'm query the BTC blockchain using blockchain.com to understand my own transactions a bit better.
One thing that confuses me in the inclusion of the Pkscript (scriptPubKey) under "Inputs" in the transaction manifest. My understanding is that this script is part of the Output of a transaction.
I presume that its inclusion here is a reference to the Output of the originating transaction i.e. the Input of the current transaction includes a part of the Output of the previous transaction to provide extra information to the user.
ie it is not suggesting that the scriptPubKey is actually part of the Input of the current transaction.
e.g
https://www.blockchain.com/btc/tx/7da0823ebf7a002a15b6bd11c676c6c213c349c982a9c454539e3ad63e9d57ee


texts: What is an "insecure transaction type", as mentioned by Bitcoin Wallet for Android?

texts:
I am running Bitcoin Core v0.11.0.0-gd26f951 (64-bit) at home on Ubuntu, and have installed the Bitcoin Wallet for Android on my phone. I sent two transactions from home to my phone: First, Second. One had a very low fee and took days, so I sent another one with a slightly higher fee which took only minutes. Both arrived though, and have almost two thousand confirmations by now and show green in the app.

The Bitcoin app now (I first noticed it today and I don't think it initially said it) says

 This payment was delayed because the sender used an insecure transaction type.

underneath both transactions. What does that mean?

I googled the phrase and got exactly one hit, in a resource bundle that is part of the code for the bitcoin-wallet project on github, which appears to be the Android app. The corresponding key is transaction_row_message_received_rbf, which generated no hits at all.

Can anyone tell me what this "insecure transaction type" could be, and why Bitcoin-Qt would be using it? Do I need to prevent it, and if so how do I do so?


texts: I used a BTC mining site and paid the fees but never got paid

texts:
[Where I paid mining fees and never got my BTC][1]

the transaction from my wallett shows 150 confirmations. I am new BTC can anyone help with this so i can understand WTF happened and am I just straight effed on the fees i paid. Thanks for your time help I appreciate it. I used the following site http://getbtc.online/dashboard/ one puts in the amount to be mined, the miners mine it and then you pay fee. Afterwards it should deposit the selected BTC amount in your wallet. Mine never got deposited in has several hundred confirmation and i know my wallet address is correct. The miners got paid; This is the site I get after I click on the confirmations in the wallet. I hope this is better as I stated previously; I am new to this and not sure WTF is going on. https://btc.blockr.io/tx/info/c842cc71b4f5133896a6302e208179400d57a79e885b617c4e21489e708fe2d1


texts: How to physically configure graphic card for higher yields?

texts:
If I were to purchase a motherboard with 7 pci-ex ports. Could I then attach 7 graphic cards and run 7 cgminer processes? One for each card?

Or would a better build be to group cards together with SLI/Crossfire?

If one of these cards generally gives 1200mhash, would i be correct to assume that 7 would give me 8400? Or is there some overhead issue here I'm not aware of?


texts:
I understand that one can create a Bitcoin wallet as a pair of numbers (public & private key) with the right specifications and this is done quite easily in places like bitaddress.org
I also understand that the probability of generating two identical public keys is infinitesimally small -- lesser than the probability of being hit by an asteroid, or so I am told.
But it is not zero.
My question is - if a duplication occurs, a hash collision happens, how does the protocol (a) detect it and (b) deal with it. In a simple, everyday hash table application, we do a lookup on the existing hashed values and if we detect a collision we ignore the last created value and generate a new one.
Is there a similar protocol in bitcoin ( or any crypto) address generation?


texts:
Simple question but I couldn’t find the answer anywhere.

What’s the 65 bytes version of those public keys ?

0229b3e0919adc41a316aad4f41444d9bf3a9b639550f2aa735676ffff25ba3898
02f15446771c5c585dd25d8d62df5195b77799aa8eac2f2196c54b73ca05f72f27

which for reference yields according to Bitcoin core getrawtransaction 5ed3694e8a4fa8d3ec5c75eb6789492c69e65511522b220e94ab51da2b6dd53f 1 "00000000000000001e76250b3725547b5887329cfe3a8bb930a70e66747384d3" :

18p4JBHP3EAKCc4jqN8XzuEJtvq8G9NAot
1Dh8oSChJWZQx5sr7ePsBNtw7uKMsNnYNC

with transaction output being :

1 04ad90e5b6bc86b3ec7fac2c5fbda7423fc8ef0d58df594c773fa05e2c281b2bfe877677c668bd13603944e34f4818ee03cadd81a88542b8b4d5431264180e2c28 0229b3e0919adc41a316aad4f41444d9bf3a9b639550f2aa735676ffff25ba3898 02f15446771c5c585dd25d8d62df5195b77799aa8eac2f2196c54b73ca05f72f27 3 OP_CHECKMULTISIG

So that while the first Public key is uncompressed, they are no version uncompressed version of the 2 others keys on the Blockchain which means Bitcoin core is recovering the 2 addresses above from the compressed public keys (the first one being not included because the Public key is uncompressed).


texts: Correct way to convert a 256-bit private key to WIF?

texts:
On the Bitcoin wiki it has steps to convert a private key to WIF. So I tried following these steps in attempt to get the same result.

So I took the private key.

0C28FCA386C7A227600B2FE50B7CAE11EC86D3BF1FBE471BE89827E19D72AA1D

I put 80 on the front.

800C28FCA386C7A227600B2FE50B7CAE11EC86D3BF1FBE471BE89827E19D72AA1D

And then I performed SHA-256 on it using this.

e2e4146a36e9c455cf95a4f259f162c353cd419cc3fd0e69ae36d7d1b6cd2c09

And that is where I run into a problem. On the wiki page it says the result of SHA-256 should be...

8147786C4D15106333BF278D71DADAF1079EF2D2440A4DDE37D747DED5403592

And that does not match my SHA-256 result.

Not sure what I am doing wrong.


texts:
Looking to fetch the UTXOs for a given address and can't seem to find the correct command syntax.

Here is an implementation in bitcoin-core via javascript, but I also experience the same on bitcoin-cli

const descriptorAttempts = [
    '{ desc: addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo) }',
    '{ "desc": "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)" }',
    '"desc": "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)"',
    "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)",
    "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)",
    "addr=34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo",
    "34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo",
    "{ addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo) }",
    "{ addr: 34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo }",
    "{\"desc\": \"addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)\"}",
    '\"{\"desc": \"addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)\"}\"',
    '"{"desc": "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)"}"',
    '"{"desc": "addr("34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo")"}"',
    '\"{\"desc": \"addr(\"34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo\")\"}\"',
    '"desc" => "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)"',
    '[ "desc" => "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)" ]',
    { "desc" : "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)" },
    { desc : "addr(34xp4vRoCGJym3xR7yCVPFHoCNxv4Twseo)" }
]

descriptorAttempts.forEach(attempt => {
    client.command('scantxoutset', 'start', [ attempt ])
    .then((res) => {
        console.log("Success! ")
        console.log(res)
    })
    .catch((error) => {
        console.log("Failed attempt of -> " + attempt)
        // console.log(error)
    })
})

All result in RpcError: Invalid descriptor


texts: Is it possible to catch up missing blocks with zeroMQ if script was down for a while?

texts:
I use zeroMQ to get all new blocks (rawblock or hashblock). If my script is down for few minutes or hours and I missed few blocks, is it possible to catch up all missed blocks with zeroMQ when I restart the script ?
During this time, bitcoin-core is always running.


texts: What are the methods for getting an old, used windows P.C. ready for secure Bitcoin usage?

texts:
Let's say I am about to set my Grandmother up with a wallet. I have no idea what she has on her computer. There could be a host of malware, keyloggers etc. Let's also say that a complete wipe and reinstall is not an option.

I was thinking of what steps I could use to give the maximum protection.

I could use CCleaner to wipe any temporary files. This will remove any excess past data she has generated.
I could then use a program spybot search and destroy to check for any malware.

What else could I do to check if there are any threats on the computer?


texts: Why do pools give rewards to miners who solve problems at a lower difficulty than the network?

texts:
I'm trying to understand why a pool would want to give rewards to miners who mine at low difficulty.  Please tell me where this logic falls apart.  If the network difficulty is a nonce ending in 100 zeroes, but a miner solves a hash (not sure what words I'm supposed to use here) with a nonce ending in only 10 zeroes and submits that to the pool, the pool now knows that this particular nonce ending in 10 zeroes is not valid so other miners don't need to work on it, and as such the miner who just solved that problem has saved others some time, so they are entitled to a reward?

Ultimately what gains the pool any rewards at all is if someone solves the hash matching (or greater than) the network difficulty so I'm trying to understand how solving a problem at a lower difficulty helps the pool (and thus leads to rewards for that miner).


texts: Effect on economy if Bitcoin was widely adopted

texts:
What would the effects be on the world economy if several million people around the world would utilize the Bitcoin currency for their daily transactions? Would you expect the GDP to grow faster or slower and why?

I am interested in this, because the first thing I want to get straight is whether I would contribute something positive if I supported the project.


texts:
I am looking at getting a Bitmain AntMiner U1 1.6GH/s - USB Bitcoin ASIC Miner to mine LTC and doing a few calculations.

I have used a few LTC profit calculators:

https://bitmakler.net/Litecoin___mining
http://www.coinwarz.com/calculators/litecoin-mining-calculator
https://www.litecoinpool.org/calc

They all seem to vary between about $40 - $70 a day? Is this correct? That seems quite a lot, for what it is.


texts: I recently tried to make a transaction with coinbase. In a hurry I put no fee though. It's still unconfirmed and blockchain.info doesn't recognize my hash. But my btc qt wallet is debited. My question is what is the longest unconfirmed transaction you've heard of? Mine is going on 16 days. I'm curious because I would still like the transaction to still go through.


texts:
I have read man resources and questions about HD Wallets. As pointed out in this question on SO, it won't be possible to send funds of a derived child address using the master private key.

In my humble opinion exactly this would make sense if I could create a derived child to receive funds for a specific purpose but being able to spend these funds using my master private key without the need to store each child private key.

Do I miss something here? Why should I use HD wallets if I still need to store each single local private key as well?


texts:
I've got a transaction from 2017-12-06 that's still unconfirmed - i really need this money now as ive moved house - how can i get this sorted - I am will to pay for help at this point.

Can anyone please help?? Tim.

https://blockchain.info/tx/44c784d8f82d962103ffdf5d463a1460150a21cc67a0750d4a3f6a35a0d18d9a


texts:
Always when i need free address (not labled) i use:

getAccountAddress('')

And i want to know: Can it give me an already occupied address (by label)

I'm worried that I can get an already address in using (by label)


texts: Order list or trades history Btce via api

texts:
Im trying to get my orders list or trades list via Btc-e Api but it always return 0 is bugged or what ?

 if (accountKey != null && accountSecret != null)
            {
                btcApi = new BtceApi(accountKey, accountSecret);
                info = btcApi.GetInfo();
                int ceva=info.TransactionCount;
                var transHistory = btcApi.GetTransHistory();
                var tradeHistory = btcApi.GetTradeHistory(count: 20);
                var orderList = btcApi.GetOrderList(count: 20);
                var tList = BtceApiV3.GetTrades(new BtcePair[]{BtcePair.ltc_usd},20);

            }


texts: What server-side Bitcoin clients are available to serve information?

texts:
I have been toying around with the idea of building a bitcoin app. My research has thus far led me to conclude that it makes sense to run a bitcoin client daemon on my server in order to provide an API for my mobile app.

Is bitcoind any good for this? I used the -server mode of the Bitcoin-qt client for mac, as explained here, and it seems to be very slow for most of the RPC calls. Is the daemon any faster? It seems like something this slow is not preferable to run on the server, and would almost force me to cache some responses that would probably be unnecessary for a faster running client (obviously, down the road cacheing would make sense, but for the initial small scale of this, I would like to avoid it.

Are there better server-side clients I could run that would perform better than bitcoind? Do any of them provide better interfaces that JSON-RPC, or is there some reason that JSON-RPC is intrinsically better for this sort of use-case? How about a REST API?


texts: How does estimated coins calculated on Coinotron?

texts:
On 'Cointron' their is wallet table after logged in into the site, how they calculate estimated coins per day, estimated rewards, confirmed rewards and unconfirmed rewards?

How does Coinotron derive this value?


texts: When an attacker publishes a longer chain, does Bitcoin Core emit a warning?

texts:
I tried answering a question about a majority-attacker's power to change the blockchain yesterday.

There is one thing I haven't been able to get a clear picture on, yet:
When a previously unknown chain fork of at least 7 blocks length is published, how does Bitcoin Core react?

main.h: CheckForkWarningConditions appears to emit a warning stating "Chain state database corruption likely".

Would Bitcoin Core accept the chain fork if it had the most work? How prominent is the warning to the user? Does Bitcoin Core need manual intervention to decide which fork to accept?


texts: How do I do the maths for starting a bitcoin mining startup in Kuwait?

texts:
Kuwait has the world's cheapest electricity which makes it a good choice for bitcoin miners. I am talking to a businessman in Kuwait who is interested in helping me move to Kuwait from Pakistan and provide me with the required hardware if I am able to convince him it would make a good profit.

I am looking for the details of all the costs involved in starting a bitcoin mining startup and its costs in Kuwait.

Thanks


texts:
I am looking for open source mobile wallet which supports electrum protocol.

Already found 2:

https://github.com/coreyphillips/moonshine
https://github.com/ACINQ/eclair-mobile

But first one looks buggy and unfinished.
Eclair-mobile is too bound to its back-end Eclair core part, which is written in Scala. Sorry but for me its overkill.

Can community recommend any other OSS Electrum mobile wallets?


texts: What is the difference between time, blocktime and timereceived?

texts:
What is exactly the difference between

time, blocktime and timereceived

in transaction information returned by Bitcoind JSON RPC API? For example:

{
    "amount": 0.02,
    "blockindex": 45,
    "time": 1306179671,
    "category": "receive",
    "confirmations": 109244,
    "timereceived": 1306179671,
    "address": "1P5xanGEdgPKYNt4BnATambHpbZ2h89bYv",
    "txid": "91eb6cb34b9253cce0ab5da171a0f5aae9d3d36208e23062ba61cd9e21c09a3d",
    "blockhash": "0000000000002e65f5cc554e99c352af958a63f4be663627f2c569e5a996a03a",
    "account": "",
    "blocktime": 1306173564
}