texts:
I found these two questions very helpful in understanding HD wallets

1) How do hierarchical deterministic wallets work transaction-wise?

2) a few questions about how HD wallet works

However, I'm still not clear how sending payments would work in the case of HD wallet. Assume the following scenario:

derived public key #15 received 1 BTC in one transaction
derived public key #20 received 2 BTC in one transaction

Now that I want to send 2.5 BTC to some address, what is the procedure of doing that? Do I need to do two separate transactions?

Also I found it overall confusing in terms of what are taken care of by the wallet (bitcoin-core, etc) and what should be done by the user. Thus, would appreciate it if anyone can explain the above by highlighting some steps in bitcoin-core for example.


texts:
I just came across the term "taint analysis" in a crypto-related conversation.

This came up while discussing "tracking bitcoin transactions" so it's somehow related to that. That's all I know.


texts: bitcoind synced more blocks than in the blockchain?

texts:
I just installed bitcoind on a fresh Ubuntu server and synced.

However, it seemingly have synced more blocks than there are in the blockchain!

$ bitcoind getblockcount
309905
$ curl http://blockexplorer.com/testnet/q/getblockcount
26787

How is that possible?

Is there something wrong with my installation?
Do I have to remove it all and restart from scratch?

Here is my bitcoind config:

#testnet=1
server=1
#daemon=1
rpcuser=[redacted]
rpcpassword=[redacted]
rpctimeout=30
rpcallowip=127.0.0.1
rpcport=19332

addnode=95.85.39.28:18333
addnode=46.4.106.234:18333
addnode=94.102.53.181:18333
addnode=5.135.159.139:18333
addnode=188.226.138.211:18333
addnode=188.165.238.173:18333
addnode=46.28.204.15:18333
addnode=109.201.135.216:18333
addnode=5.9.2.145:18333
addnode=46.182.106.2:18333
addnode=109.201.154.201:18333
addnode=188.165.246.217:18333


texts: Bitcoins Anonymity - Do Exchanges Break It?

texts:
If I used to pay for bitcoin for something illegal (as defined by my country), and the public key of the wallet I used to spend the bitcoin became known, could authorities subpoena bitcoin exchanges for information regarding any accounts of anyone who bought bitcoin and sent the BTC to that public key? If any bitcoin was sent to me from someone (possibly myself) who had their bank account linked to an exchange, it seems the exchange could obviously identify the person associated with that account which could lead to information about my identity.
I have no intentions of doing anything illegal, just curious :D
It seems the exchange of USD for BTC almost requires bank account information.


texts: When I buy a Bitcoin with dollars, where does the money go to?

texts:
I understand the networking concept of the coin, but I am not sure I understand the purchase process.

Let's say I have 1000$ that I want to spend on Bitcoins, who do I give this money to?


texts: On Multibit, one of my transaction to Bitstamp is not confirmed since 5 days (Status icon displays a white square). Apparently the 0.0001 fee was paid. I don’t know where is the money neither what to do.


texts: What are best practices around toggling between multiple wallets in bitcoind?

texts:
I've created a couple wallets on Core to experiment with and want to dedicate one wallet as a live one.  What is the best way to move between those wallets inside the command line?  When I toggle to a wallet that is not the default in the GUI and try some bitcoin-cli wallet commands it get an error

Wallet file not specified (must request wallet RPC through /wallet/<filename> uri-path)

Is it just a matter of passing a wallet file name into the command? Or is there a better way to manage multiple wallets? Other best practices to a multi-wallet setup (i.e. don't)?


texts: What is the probability of mining a block by a miner controlling a fraction of hashing power?

texts: Suppose a miner controls α fraction of the hashing power and the chain on which he is trying to mine has the mining rate given by f. How to find the probability of mining a block by the miner?


texts: Even though Blockchain is tagged as " Decentralized", wouldn't the organization actually implementing the Blockchain like Ethereum control it?

texts: For example, If I were a business that would want to use the Ethereum Blockchain technology to shift my business to Blockchain, wouldn't Ethereum be in control of the actual underlying Blockchain technology? Wouldn't it have the power to for example change the consensus algorithm or change the underlying technology? If I am missing something here please explain.


texts: how do i identify the location of a transaction?

texts:
I have an old coinbase account and can't figure out for the life of me where I would have sent the coins.  What is the best way to determine the owner or location from a bitcoin address?
14vRCiVnT4Su1akXrKmUUa3Ucf971pJXsB


texts: Is there any source that visualizes how SHA-2 works (including internals) with animated video or an interactive web page?


texts: BIP 32 seed resulting in an invalid private key

texts:
everyone.

For my final year project, I'm developing some Bitcoin/Bitcoin related technologies (BIP32, BIP 38, BIP39, Bas58Check encoding/decoding, etc) in pure Node.js (using only native libraries, such as 'crypto').

After writing the module dealing with BIP32 wallet generation, I wrote a bunch of tests trying to cover 100% of statements/branches/functions/lines, but there's one scenario I can't seem to reproduce, due to it being very unlikely to stumble upon.

Given a random seed, you apply HMAC-SHA512 to get the master extended private key. In it, there is a private key, which can be invalid if equal to 0x0000000000000000000000000000000000000000000000000000000000000000 or greater than 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364140.

Have you guys seen any seed which generates an invalid private key? I looked through the internet for such known value and could not find it.

The same can happen when generating children private keys. Is there any known parent private key + parent chain code + index resulting in an invalid private key?

Thanks a ton!


texts: I need help with an bitcoin open book exam

texts: I am completely new to bitcoin and by extension cryptocurrency, but I am slowly getting my head around certain things. My problem is I am currently doing an open book exam and I am free to use any resources available to me. One of the questions asked was "What is the address with the path m/0/2 for the following wallet: zpub6nQF4m3JT6hTkQ4o9Vc8LDMQx7nMkT5CsnPgVHnnrpF9JHeP6ioboEK2CXB34Xn6nzqcJnLPuMqQaKqBhwvZR7GJNvSeRUpDpCaVu3N3stz"? Is there a way to find this out or is this a trick question since from the hours of research I have done so far I have found that zpub and xpub keys are used to generate actual public addresses. Can you please point me in the right direction?


texts:
Everytime when i run bitcoin cash testnet core on raspberry pi 3, it just stops for some reason and debug logs end at loading wallet.

So does the raspberry pi 3 cant handle bitcoin cash testnet wallet?

Here is the log that ends everytime:
2018-01-29 00:53:20 init message: Loading wallet...


texts: Why are there equal send transactions for each receive on Bitcoin Core?

texts:
I've lunched a new Bitcoin core wallet, and generated some addresses using it. Then I tried to receive some BTC to these address, and then, found out if I receive some BTC, there are equal send transactions too on the same address.
All incoming BTCs are in my wallet, and there is not any problem up to now. But I wonder to know what are that send transactions? I am paying fees for them automatically!

This is an example:
https://www.blockchain.com/btc/address/3PiCVEFLHPiexXf15UB7nw9yBMZTWjP73C


texts: How can I avoid transaction malleability consequences?

texts:
Please note that this question is NOT a duplicate of other questions regarding transaction-malleability.

My question is regarding a following scenario, that could happen on an exchange that uses on-chain wallet management:

user deposits funds on address A, belonging to his account on an exchange. Exchange waits n confirmations before it credits user account.
user then moves funds from address A to address B, which also belongs to his account on the same exchange. Exchange doesn't wait for any confirmations here, because the it knows it won't double-spend itself. Exchange thus notes the TXID of this transaction for future use.
while transaction is unconfirmed, someone exploits transaction malleability issue and pushes its tweaked version, which gets picked up by miners instead.
in the mean time, user wants to withdraw funds to address C, which is another exchange or external wallet. Exchange creates this transaction using TXID that it stored earlier. Unfortunately, Blockchain doesn't know this TXID because it was rejected by majority of miners. The exchange though doesn't get immediate feedback about that, because it doesn't know that a tweaked version of that transaction exists (since both are still unconfirmed)
in effect, funds are not withdrawn, and exchange operators are left wondering why this happened.

Now the following situation has NOT happened to me (yet), but I'm wondering:

is it realistic enough that it could happen, or is there something I missed?
how I can guard against this? For me it seems that the best fix for this would be use of the new NTXID instead of TXID in transaction inputs. But that will probably not be possible in near future, because required quite a big change in the protocol.


texts: Multibit export private key to usb possible?

texts:
I have Multibit and want to export my private keys as a backup.

1) I cant see my external usb as a option when selecting a destination to export to.  Is this because cant export the private keys directly to a usb?

2) Once exported, is that it to make a back up of the private keys, or do you then have to re-import the private keys to transact in the wallet?

Thanks


texts: What is the formula for inferring hash rate from difficulty and block frequency?

texts:
Two parts to this question
1/ There have recently been concerns over drops in hash rate observed on sites such as blockchain.com. However, my understanding is that hash rate is inferred from the difficulty level and the block intervals. I am trying to work out the exact formula for the inference of hash rate.
I know that the average time we can expect to find a block in is calculated with the following formula:
average time to find a block = (difficulty * 32 ** 2)/ hash rate

Would that mean that hash rate is inferred with the following formula?
hash rate = (difficulty * 32 ** 2)/ time interval between the last two blocks

2/ I mainly want the first part answered but if you are feeling rosy today, an answer to this second part would be amazing.
Block times are Poisson distributed. I understand that this allows us to calculate the probability that block times increase to such an extent over the course of a day that it infers a 40% reduction in hash rate.
Does anyone know the exact calculation which would let us calculate this probability?
Here's some rough ideas I have about the calculation:
The following formula allows us to calculate the probability that k events take place in time period t.
P(k in t) = (e ** -lam)*(lam**k / k!)
where lam = (average events which can be expected to be observed per unit of time  * t)

The average events which can be expected to be observed in the case of block intervals is 1 block per ten minutes so 1/10.
Let's say we have hash rate dropping 50% over the course of one day, would that imply that we are observing 288 blocks over the course of 1440 minutes?
If I am thinking about this in the correct way, this would mean the calculation is as follows:
P(288 blocks in 1440 minutes) = (e ** -(144)*((144**288)/288!)

Not sure if this calculation is correct. But to take it further, this would calculate the small probability of exactly 288 blocks being found in 1440 minutes. But if it were possible to calculate the Poisson distribution of block intervals, we may be able to find the probability of finding greater than or equal to 288 blocks in 1440 minutes.
As you can probably tell, my understanding of the second part of the question is limited so if you have an answer to even just the fist part, that would be amazing!


texts: I just installed bitcoin core client (from github) and started the client. It took around 24 hours to install the full block chain. Where did the blockchain come from? How did did my bitcoin core client find its first peer on the network?


texts: Failed transaction, but my wallet shows 0 balance

texts:
I made a mistake 10 days ago when I sent some bitcoin from my wallet to another one. The problem is, because this transaction was my first one, I set the transaction fee to the bare minimum. You can guess, that I did not see my BTC since then.
According to blockchain.com, the transaction has failed, and my address has all the BTC that I wanted to sent. So far so good, but in the wallet (Atomic Wallet), my balance is near 0. I asked the support, but I didn't get any useful information, just to wait... as I said, it happened 10 days ago.
Next, I created a new wallet in Trust Wallet, add the 12 phrase seed which I get from Atomic, hoping, that its only an Atomic bug but... Trust showed near 0 balance too.
So here is my question: how can I get back my BTC from the blockhain universe? I read something about Replace By Fee and Child Pays For Parent methods, but I'm not sure that these can help me. Or am I wrong?
The transaction.


texts: Would it be possible to send money through the Lightning Network to an offline address?

texts:
My understanding is that the current Lightning Network spec requires an address receiving money to sign things with its private key - which requires the owner of that key to be online. Are there any techniques that would allow some 3rd party to accept money on your behalf without trusting that 3rd party?

I can imagine a situation where the sender delegates sending to a 3rd party, just like posting anti-cheat transactions can be delegated to a 3rd party that watches the blockchain. For example, maybe the sender gives a 3rd party the proper transactions needed to authorize sending lightning btc to the destination once the destination comes online. I don't know if this is possible with the current functionality in Bitcoin, tho. Is this possible?


texts: Is there any part of a bitcoin transaction that is 'random' or could not be predicted?

texts:
I am just curious if when a transaction is sent and you view it on the blockchain. Is any of that information impossible to predict what it will be?

I am looking at perhaps the time received ? (you may be able to guess close but maybe not down to the second?) or the relayed by ip?

Does that make sense? I am guessing not since according to: Are transaction hashes random? the transaction hash is not random, but still want to clarify.

Likewise, looking at the coinbase api:

GET https://coinbase.com/api/v1/transactions/5018f833f8182b129c00002f

# Response
{
"transaction": {
"id": "5018f833f8182b129c00002f",
"created_at": "2012-08-01T02:34:43-07:00",
"amount": {
  "amount": "-1.10000000",
  "currency": "BTC"
},
"request": true,
"status": "pending",
"sender": {
  "id": "5011f33df8182b142400000e",
  "name": "User Two",
  "email": "user2@example.com"
},
"recipient": {
  "id": "5011f33df8182b142400000a",
  "name": "User One",
  "email": "user1@example.com"
}
 }
 }

Could the 'created_at' time be considered random?

Thanks.


texts: Difficulty to Hash Validation Correlation

texts:
In the validation of a block it is said that a miner has a valid block if the transactions can be tracked in the chain and the hash of the block header is less than the difficulty. I am having a hard time seeing the relationship in real world blocks that are being solved.

For Example from Block#496785 :

Difficulty("target") = 1,347,001,430,558.57
or in hex
000000000000000000000000000000000000000000000000000001399F8AB21E

Mined Hash = 000000000000000000cf3620d570d08d1799a1cafbbfae512fdba2124665eca0

so it seems to me the hash is now greater than the difficulty so an invalid block but this is obviously not the case.

I have heard also that the difficulty is related to the number of leading zeros after the maximum target in which case may make sense where 1399F8AB21E is a 11 byte number and the hash after the default 8 byte leading target contains 10 bytes which is less than the difficulty 11 bytes of zeros.

so

00000000 0000000000 cf3620d570d08d1799a1cafbbfae512fdba2124665eca0
8 bytes  difficulty             some value

Is this correct? How does this work?


texts: Can a bitcoin transaction be used to send usernames?

texts:
I'm looking to implement a secure mobile messaging service and looking for a payment system that will allow users to buy message credits and have them be allocated to a specific account however I want to keep user data to a minimum (currently I'm planning for no more than a public key, user name (five random characters), account balance and optionally an e-mail address (in case the user loses their phone).

My questron is can I send the five character username with bitcoin transactions?


texts: Are Bitcoins anonymous or tracable? Any changes from "How anonymous are Bitcoin transactions?"?

texts:
After the hacking and closing of Mt Gox there has naturally been some talk if there is a way to recover the lost coins.  One "expert" commented that this would be a great test of the claim that BitCoins could be easily traced and thus supirior to other currencies in cases like this...

I (on the other hand) was under the impression that BitCoins were anonymous - or at least semi-anonymous... with som precautions.

Now I've read the "How anonymous are Bitcoin transactions?" on this site, and things are a bit clearer to me.  But this seems to (partly) contradict the claim that BitCoins are especially tracable.

So what is correct?  Has there been any major changes since the "How anonymous are Bitcoin transactions?" was written?

How anonymous are Bitcoin transactions?


texts: Ideal passphrase length: old diceware method (5 words) vs. your Bitcoin wallet.dat passphrase length (8 words) and doubling passwords?

texts:
I made a cool 5 word passphrase back then using the old Diceware method and use it as a master password. The question is: as computing power increases, will we need to add more and more words to our passphrases which we will eventually forget? I'm in my mid 30s, will passphrases be enough in my lifetime? :) So back then, Diceware suggested just 5 words, not the original Bitcoin QT client recommends 8 words. Will the original 5 words from the Diceware age serve me in the Bitcoin age?

I don't really want to mess around with a Yubikey. Heck, I Googled it and didn't really managed to find out what it is, what it does. Maybe I'm not the target market. I'm just a simple user. Carrying around a Yubikey would also be a red flag in my eyes. He has secrets!

How effective is doubling a passphrase? Like I have now [passphrase] and simply doule it: [passphrase][passphrase]. So I don't really have more stuff to remember, just more stuff to type. That might serve me for a time.


texts: What are the exact steps for creating a transaction and having a valid block?

texts:
I have read all kind of the articles and I understand almost all the concept from cryptocurrency. What I still don't understand is, what are the steps from transactions to a valid block.
On a post on this SE I found this:

Collects transactions from the network
Validates them, and doesn't allow conflicting ones
Puts them into large bundles called blocks
Computes cryptographic hashes over and over until if finds one "good enough to count"
Then submits the block to the network, adding it to the blockchain and earning a reward in return.

Let's take a practical example and please correct me if I make some wrong steps:

I send 10BTC to Batman.
Because I have send BTC, a transaction is created in system.
This transaction is send to all nodes from network (all users)
After transaction arrives to all users, the transaction is added in a queue where the miners take take their transactions.
A miner take transaction, process it (proof of work) and creates a block with more transactions.
After all the transactions are validated by miner, the new block is send in the network for check.

Now, questions:

How does each user check this blockchain (divide the blockchain and check each transaction if the transaction from the blockchain is the same with the one that he has (because first transactions are send to all the users from p2p network and after that are send in the queue to be process by the miner. This is how user is able to compare the transactions))?


texts: NBitcoin Transaction sign(secret, bool) is giving error. Instead of bool it says to pass Coin Object

texts:
I am using NBitcoin (I'm new to it) to sign a transaction. Here Transaction sign(secret, bool) method is giving error. (I've searched the Internet, but got no help.) Instead of bool it says to pass Coin object, I'm using the latest stable version of NBitcoin. How should I do this? Here's my code:
var fee = Money.Coins(0.0001m);

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

        payment.Outputs.Add(new TxOut()
        {
            Value = amount-fee,
            ScriptPubKey = toAddress.ScriptPubKey
        });

        var output = fundingTransaction.Outputs[0];

        payment.Outputs.Add(new TxOut()
        {
            Value = output.Value - amount - fee,
            ScriptPubKey = output.ScriptPubKey
        });

        var message = "Thanks :)";
        var bytes = Encoding.UTF8.GetBytes(message);
        payment.Outputs.Add(new TxOut()
        {
            Value = Money.Zero,
            ScriptPubKey = TxNullDataTemplate.Instance.GenerateScriptPubKey(bytes)
        });

        Console.WriteLine(payment);

        payment.Inputs[0].ScriptSig = fundingTransaction.Outputs[1].ScriptPubKey;

        payment.Sign(secret, false); // the problem arises here

        using (var node = Node.Connect(Network.Main))
        {
            Console.WriteLine("Doing version handshake");
            node.VersionHandshake();
            Console.WriteLine("Sending message");
            node.SendMessage(new InvPayload(InventoryType.MSG_TX, payment.GetHash()));
            node.SendMessage(new TxPayload(payment));
            Thread.Sleep(500);
        }


texts:
For transaction not spending SegWit outputs it's straightforward: if I have 1000 Satoshi fee set for 500 byte raw transaction, I end up with 2 s/b fee.

How about transaction containing witness data?

Say, my raw transaction is 500 bytes,100 bytes of which are witness data. Thus, 400 bytes are now competing for the place in 1 Mb block.

How accurate is it to say that current transaction fee is 1000 / 400 = 2.5 s/b?


texts: Can Bitcoin software be used to create a private currency (single issuer)

texts:
I understand Bitcoin software can be used for private currencies. Can it be used to create a private currency (the NewCurrency) where there is only one issuer of NewCurrency and any monies raised are invested. So that investments "belong" to the holders of the NewCurrency, and any returns on the investments benefit the holders of the NewCurrency (i.e. improve exchange rates against other currencies). Issuer of NewCurrency can quote the net asset value of the investments daily (like for open ended funds), which supports the value (i.e. exchange rate) of the NewCurrency?

Does Bitcoin software/infrastructure support implementation of this?


texts:
Given the volatile bitcoin value, how long is a transaction valid? For example, say a vendor requires X fiat currency via a bitcoin service provider. The service provider link (ie, coinbase.com) contains instructions (also via QR code) to pay Y bitcoins to account Z per the current market rate (this might include a transaction fee, I'm not sure). How long is this link valid?

Say the bitcoin value halves 24 hours later. Would I have saved X/2 money?


texts: Transfer BTC from Coinbase to Bittrex: fee static or percentage

texts:
I want to transfer BTC from Coinbase to Bittrex. Now I only have a very small amount of BTC to transfer. But I have some money in my wallet with which I will buy BTC and transfer it later.

Now is my question. Is the fee to transfer the BTC static or is it a percentage?

So does it matter if I transfer twice (one 1 BTC, later 10 BTC) or at once (11 BTC)?


texts: Where is SIGHASH_TYPE serialized in SegWit?

texts:
When preparing or verifying a signature, a transaction pre-image is created in memory. This pre-image exists purely for the purpose of creating a signature and is not published to the blockchain. At the end of this pre-image is a 4 bytes SIGHASH_TYPE.

When serializing the resulting transaction, the SIGHAH_TYPE is truncated to one byte and added at the end of each signature. The remaining 4 bytes are not put at the end of the final transaction (here's why, probably).

How does this work with SegWit? Is 1 byte appended to the signature in the the same way, but in the witness data rather than the legacy part of the transaction? It's not immediately obvious to me based on the examples in BIP143.


texts:
I'm thinking about using a mixing service like Blockchain.info's Shared Sending. I don't have anything to hide, it's just about privacy. My concerns are about where my bitcoins will go. I'm sure some people are using these mixing services to do illegal things like buying drugs, so I'm afraid if I use a mixing service, one day the police will knock my door asking questions because my original bitcoins went to a drug dealer or something worse.

So, are my concerns justified?


texts:
How are colored coins enforced?

A signature can easily be rejected, and so can a block.

How does the blockchain enforce that a particular asset is tied to the colored coin or has been delivered?

I can see how another cryptosecurity could be tied to a cryptocurrency, but does the blockchain physically manifest itself, kick down the door of 31uEbMgunupShBVTewXjtqbBv5MndwfXhb, and collect the asset if 31... doesn't deliver?


texts: Transferering Bitcoins from Coinbase to Binance

texts: I've heard people say that you should transfer your Bitcoins from Gdax to Binance. I bought my Bitcoins on Coinbase. Is there a way to transfer your cryptocurrency to Gdax without paying that overwhelming fee?


texts: I'm currently building a small bitcoin order book simulator that would mimic user limit orders. What gives order books its V shape appearance? That is, the further away we go from the market price, the more orders are stacked. For sellers, is it mostly profit driven, they want to sell higher than market price, and for buyers, they just want to buy cheaper than the market price? Is it mostly as simple as that? Plus maybe people wanting to trade the breakout?


texts: Without IP address, are there any other identities considered for banning nodes

texts: Does a node only ban the IP address of a malicious node? or, there are other identities included. I mean, if a malicious user can generate multiple IP addresses to send fake tx, what will be the countermeasure then? Suppose, the other node, which will verify this tx, also a malicious attacker.


texts:
I was examining the block hashing algorithm and I tried to hash some blocks with my c++ sha256 to check results.

The hashes were wrong all the time so I thought I couldn't build the block header properly but then I took the data from wiki https://en.bitcoin.it/wiki/Block_hashing_algorithm and concatenated the values from the example and the result is still wrong (I tried it also in online sha-256 calculator so the function is ok).

Of course I must be missing something like coding but if I understand it right, sha is a function where you give a message and it takes the ascii codes of the message and does the math operations on these codes. But how can I pass a block header as a string? Or do I have to find an implementation of sha that interpretes the input differently?

I'm sorry, I know it's a noob question but this doesn't seem so obvious to me.

Edit:

The code is quite complex, but what I have at this moment is basically a made up block header that I packed in a string and for the example from the wiki page I mentioned above the string looks like

0100000081cd02ab7e569e8bcd9317e2fe99f2de44d49ab2b8851ba4a308000000000000e320b6c2
fffc8d750423db8b1eb942ae710e951ed797f7affc8892b0f1fc122bc7f5d74df2b9441a42a14695

I also have a sha function that takes a string as an input so the hash should be

1dbd981fe6985776b644b173a4d0385ddc1aa2a829688d1e0000000000000000

but it's

cf5397ae292d5d37a0df81aa7f89f9fc7e1c43329e441ce2294f0a72e542c7d9

I also checked it on http://www.xorbin.com/tools/sha256-hash-calculator so I think the code is ok but I must just be missing something here.


texts: What is the complete process and purpose of a block validation using merkle trees?

texts:
I need the whole details please. Like does that happen only in the current block? Or at past blocks do? And how exactly does this happen? Do full nodes send the proper hashes and then a local lightweight node calculates them until it reaches the merkle root?

An example with a step-by-step process explanation would be ideal. I need all the techincal details described as simple as possible


texts: My Bitcoin Core Sent Bitcoins Without My Authorisation

texts:
I am running Bitcoin Core version v0.19.0.1 (64-bit) on Windows 7, and on 27 February I noticed that it sent 0.0045 bitcoins on its own.

The wallet is encrypted at all times and I enter the passphrase to send as required.

I did NOT initiate the Send.

I am greatly concerned. The PC is regularly checked for virus and malware.

The transaction details are:-

Status: 320 confirmations
Date: 27/02/2020 16:37
To: bc1qz944eascuflps4nmsc0w5cpz9p3cxdyqjmmqw7
Debit: -0.00447194 BTC
Transaction fee: -0.00002806 BTC
Net amount: -0.00450000 BTC
Transaction ID: 3c138afea7d634ce5e8b608e1a751122d6d33ba9bd8e00a02de02cb57aad039d
Transaction total size: 214 bytes
Transaction virtual size: 133 bytes
Output index: 0

The previous transaction:-

Status: 455 confirmations
Date: 26/02/2020 18:27
From: unknown
To: 3Hb61TTkbxPTUCA6EvUStb8PPMZUjPASfd (own address, label: coinfloor)
Credit: x.xxxxxxxx BTC
Net amount: +x.xxxxxxxx BTC
Transaction ID: 5697d9b298647c216a727f95dbdecfc658a9f8da3c45f98bc8c8a2439c8f1cfc
Transaction total size: 404 bytes
Transaction virtual size: 214 bytes
Output index: 1

The last time I sent was with this:-

Status: 43126 confirmations
Date: 17/05/2019 07:25
To: Coinfloor 5 10 13vk63282b4FkhyyV9mmgQTxpao9ECnnmB
Debit: -x.xxxxxxxx BTC
Transaction fee: -x.xxxxxxxx BTC
Net amount: -x.xxxxxxxx BTC
Transaction ID: d23b6c3f42339ace670d0ebdca4eabcfe45c34b0ccab44c9767a519682e415ba
Transaction total size: 932 bytes
Transaction virtual size: 530 bytes
Output index: 1

I would like to know how this could have happened, because I definitely did NOT initiate this send.

Any suggestions about how to diagnose this? I expect there's no way to recover the 0.0045 coins.


texts: CGMiner litecoin mining generates invalid nonce errors

texts:
It seems that litecoin/scrypt support in cgminer is unstable as I've found a lot of mentions of this error in various forums and no real solutions. Some seem to be able to resolve the problem by experimenting with different versions and combinations of drivers and AMD SDK. So far I've tried much and always the same problem. Here's the output from command line:

  cgminer --benchmark --scrypt --debug --verbose

 [2013-06-07 00:34:54] Started cgminer 3.2.0
 [2013-06-07 00:34:54] CL Platform 0 vendor: Advanced Micro Devices, Inc.
 [2013-06-07 00:34:54] CL Platform 0 name: AMD Accelerated Parallel Processing
 [2013-06-07 00:34:54] CL Platform 0 version: OpenCL 1.2 AMD-APP (1124.2)
 [2013-06-07 00:34:54] Platform 0 devices: 1
 [2013-06-07 00:34:54]  0   Tahiti
 [2013-06-07 00:34:54] GPU 0 iAdapterIndex 0 strUDID PCI_VEN_1002&DEV_6798&SUBSYS_254D1458&REV_00_4&176F368&0&0018A iBusNumber 2 iDeviceNumber 0 iFunctionNumber 0 iVendorID 1002 strAdapterName  AMD Radeon HD 7900 Series
 [2013-06-07 00:34:54] GPU 0 AMD Radeon HD 7900 Series hardware monitoring enabled
 [2013-06-07 00:34:54] Pushing ping to thread 0
 [2013-06-07 00:34:54] Init GPU thread 0 GPU 0 virtual GPU 0
 [2013-06-07 00:34:54] Popping work to stage thread
 [2013-06-07 00:34:54] CL Platform vendor: Advanced Micro Devices, Inc.
 [2013-06-07 00:34:54] CL Platform name: AMD Accelerated Parallel Processing
 [2013-06-07 00:34:54] CL Platform version: OpenCL 1.2 AMD-APP (1124.2)
 [2013-06-07 00:34:54] List of devices:
 [2013-06-07 00:34:54]  0   Tahiti
 [2013-06-07 00:34:54] Selected 0: Tahiti
 [2013-06-07 00:34:54] Preferred vector width reported 1
 [2013-06-07 00:34:54] Max work group size reported 256
 [2013-06-07 00:34:54] Max mem alloc size is 2951741440
 [2013-06-07 00:34:54] Selecting scrypt kernel
 [2013-06-07 00:34:54] GPU 0: selecting lookup gap of 2
 [2013-06-07 00:34:54] GPU 0: selecting thread concurrency of 22400
 [2013-06-07 00:34:54] Loaded binary image scrypt130511Tahitiglg2tc22400w256l4.bin
 [2013-06-07 00:34:54] Initialising kernel scrypt130511.cl with bitalign, 1 vectors and worksize 256
 [2013-06-07 00:34:54] Creating scrypt buffer sized 1468006400
 [2013-06-07 00:34:54] initCl() finished. Found Tahiti
 [2013-06-07 00:34:54] 1 gpu miner threads started
 [2013-06-07 00:34:54] Pool 0 not providing work fast enough
 [2013-06-07 00:34:54] API not running - API will not be available
 [2013-06-07 00:34:54] Generated benchmark work
 [2013-06-07 00:34:54] Pushing work from pool 0 to hash queue
 [2013-06-07 00:34:54] Generated benchmark work
 [2013-06-07 00:34:54] Pushing work from pool 0 to hash queue
 [2013-06-07 00:34:54] Generated benchmark work
 [2013-06-07 00:34:54] Pushing work from pool 0 to hash queue
 [2013-06-07 00:34:54] Popping ping in miner thread
 [2013-06-07 00:34:54] Popping work from get queue to get work
 [2013-06-07 00:34:54] Got work from get queue to get work for thread 0
 [2013-06-07 00:34:54] Generated benchmark work
 [2013-06-07 00:34:54] Pushing work from pool 0 to hash queue
 [2013-06-07 00:34:54] Generated target 00000000000000000000000000000000000000000000000000000000ffff0000
 [2013-06-07 00:34:55] [thread 0: 18432 hashes, 17.7 khash/sec]
 [2013-06-07 00:34:55] GPU 0 found something?
 [2013-06-07 00:34:55] OCL NONCE 33519 found in slot 0
 [2013-06-07 00:34:55] New best share: 6
 [2013-06-07 00:34:55] GPU0: invalid nonce - HW error
 [2013-06-07 00:34:55] Discarded cloned or rolled work

Any help gratefully received.


texts:
These are the commands I'm running after building a clean ubuntu docker image with all the dependencies:

./src/bitcoin-cli -regtest &

It yields the error:

error: too few parameters (need at least command)

Next I ran:

./src/bitcoin-cli -regtest -daemon

which resulted in:

error: too few parameters (need at least command)

finally:

./src/bitcoin-cli -regtest 101 &

yields:

error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file (/root/.bitcoin/bitcoin.conf)

These commands have been taken from the following resource:

https://bitcoin.org/en/developer-examples#regtest-mode

There's a question here, and a corresponding answer that provides a script to start regtest, is that a good solution?

Next step

so I ran first:

bitcoind -regtest -daemon

and I got the output:

Bitcoin server starting

then I tried:

bitcoin-cli -regtest getinfo

which resulted in:

error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file (/root/.bitcoin/bitcoin.conf)

these commands also generated the same output as above:

./src/bitcoin-cli -regtest help
./src/bitcoin-cli -regtest 101

so I've created the following file:

vim /root/.bitcoin/bitcoin.conf

it's literally just this:

rpcpassword=123

*also tried with this:

server=1
rpcuser=root
rpcpassword=password
rpcconnect=127.0.0.1
rpcport=8332

and now issued the command:

bitcoin-cli -regtest getinfo

which resulted in the following:

error: couldn't connect to server: unknown (code -1)
(make sure server is running and you are connecting to the correct RPC port)


texts: Has any miner ever earned their 50/25 BTC solving a block with only one or two transactions? Maybe they got lucky before the full ten minutes?


texts: I'm trying to compile Bitcoin Gold but i'm still getting this error

texts:
In file included from ./addrman.h:14:0,
                 from net.h:10,
                 from miner.cpp:18:
miner.cpp: In member function ‘std::unique_ptr BlockAssembler::CreateNewBlock(const CScript&, bool)’:
miner.cpp:197:67: error: too many arguments to function ‘int64_t GetBlockWeight(const CBlock&)’
 nSerializeSize, GetBlockWeight(*pblock, chainparams.GetConsensus()), nBlockTx, nFees, nBlockSigOpsCost);
                                                                   ^
./util.h:148:33: note: in definition of macro ‘LogPrintf’
         _log_msg_ = tfm::format(__VA_ARGS__); \
                                 ^
In file included from miner.cpp:15:0:
consensus/validation.h:100:23: note: declared here
 static inline int64_t GetBlockWeight(const CBlock& block)
                       ^
In file included from ./addrman.h:14:0,
                 from net.h:10,
                 from miner.cpp:18:
miner.cpp:197:67: error: too many arguments to function ‘int64_t GetBlockWeight(const CBlock&)’
 nSerializeSize, GetBlockWeight(*pblock, chainparams.GetConsensus()), nBlockTx, nFees, nBlockSigOpsCost);
                                                                   ^
./util.h:151:125: note: in definition of macro ‘LogPrintf’
         _log_msg_ = "Error \"" + std::string(fmterr.what()) + "\" while formatting log message: " + FormatStringFromLogArgs(__VA_ARGS__); \
                                                                                ^
In file included from miner.cpp:15:0:
consensus/validation.h:100:23: note: declared here
 static inline int64_t GetBlockWeight(const CBlock& block)
                       ^


texts: nLocketime error PUSH TRANSACTION ERROR: 64: NON-FINAL

texts:
Created nlocktime with electrum and used the time date feature which is using unix time instead of block height number for the locktime.
SO when pushing the raw tx before its time I get code 26 message non final which is fine as the time in the unix clock has not been reached.
Once the time arrived, I tried again and this time I get  non-final (code 64)  Why? And yes the btc from wallet being sent was confirmed at least with 1 confirmation. Here is the raw tx code. Any help would be appreciated as this is driving me crazy.
020000000156ab1d690e27b9d6dc3764233fa73a9749253472443e7d4efd86c7532eb58a64000000006a47304402205531d1b6808572a77bf649d480cb2f4676ead7035ed39bdb1bb1e928d5441a9102205710edaf122ec991ccab08a6945a1a728d08eecae5dbafb1e72c8481e1672f9d012102cbf41593c5fdb8caaf1942e0c4f2256de0a174c85b2d05252a9053dfc08de65afdffffff01a26900000000000017a91432d423f7e7722ed3ab0c87786e877b5f220148708795980460
{
"txid": "5b0b8137b86986fe65b2d07346d7dde9cc94ac9cd20671f5161b3bc76012a995",
"hash": "5b0b8137b86986fe65b2d07346d7dde9cc94ac9cd20671f5161b3bc76012a995",
"version": 2,
"size": 189,
"vsize": 189,
"weight": 756,
"locktime": 1610914221,
"vin": [
{
"txid": "648ab52e53c786fd4e7d3e4472342549973aa73f236437dcd6b9270e691dab56",
"vout": 0,
"scriptSig": {
"asm": "304402203a3c80d8cb01c28558269fdda6faaa7b1b963030b8867d9c0a933b9813c192c802202770970cdb704416c8fe504a9ed518537e983d2cce534fafa02046aa2181bf7a[ALL] 02cbf41593c5fdb8caaf1942e0c4f2256de0a174c85b2d05252a9053dfc08de65a",
"hex": "47304402203a3c80d8cb01c28558269fdda6faaa7b1b963030b8867d9c0a933b9813c192c802202770970cdb704416c8fe504a9ed518537e983d2cce534fafa02046aa2181bf7a012102cbf41593c5fdb8caaf1942e0c4f2256de0a174c85b2d05252a9053dfc08de65a"
},
"sequence": 4294967293
}
],
"vout": [
{
"value": 0.00026092,
"n": 0,
"scriptPubKey": {
"asm": "OP_HASH160 32d423f7e7722ed3ab0c87786e877b5f22014870 OP_EQUAL",
"hex": "a91432d423f7e7722ed3ab0c87786e877b5f2201487087",
"reqSigs": 1,
"type": "scripthash",
"addresses": [
"36Kmqv4k5cxigNvgV6Geejn7Cvc7MR3oPt"
]
}
}
]
}
It finally broadcast at 443 pm!  BUT WHY DID I HAVE TO WAIT!!!
    https://blockchair.com/bitcoin/transaction/71b27932fa35bc3fbf8343ea81e497b73b11cad7cda87485484a7e52f542c414


texts: How many numbers to try to solve the proof-of-work problem

texts:
I'm preparing for a lecture on blockchain, where I'm going to briefly explain the proof-of-work mechanism and the hashcash challenge.
To illustrate the difficulty, I want to give the maximum amount of numbers one has to try in order to find a solution, given a specific difficulty target (at this time, 18,670,168,558,400).
I believe it's a simple formula, but I can't find it again. Can someone please refresh my memory?
Thanks!
R.


texts: SharedCoin vs JoinMarket, Pros and Cons of each

texts:
Can someone please clearly specify the differences between SharedCoin and JoinMarket.

What are the advantages and disadvantages of each?

How is SharedCoin centralized while JoinMarket decentralized?


texts: What happens if I lose Bitcoin Investment, is there Bitcoin insurance?

texts:
If fiat bank money is stolen, or bank is fire/damaged, we have banking insurance. If hard money gold is stolen, it can always be replenished with Lloyds of London insurance, or with a mining annual growth rate of 2% per year.
If Bitcoin money is hacked (as it was in past), USB Drive destroyed, or the bitcoin is missing, how can a person recoup their losses?
Some of us agree, slight inflation 1-2% helps insure against losses (just like FDIC insurance, or gold insurance). Of course large inflation, where governments finance war, pointless government programs with inflation of 20-30% year is too much.
The question is, How will Bitcoin solve the insurance issue? Can be it a good storage of value to families if its lost?
Note: I'm aware fiat or gold insurance, will not work if 3rd party insurance is lacking funds. It can work however, last time, someone stole money from friend's bank account. Does bitcoin offer any level of insurance?


texts: How to get instant notification of any Bitcoin transaction involving a specific public address as recipient without knowing the wallet or private key

texts:
Everything is in the title... For instance, Blockchain can do this if you import a public address and you set up their notification mechanism.

Is there a way to do this in an intelligent (=efficient) way with bitcoind even with some patches? Or is the only solution is to get all transactions and filter for the public address?


texts: Can Ripple Unique Node Lists (of validators) be weighted?

texts:
My understanding is that in order to limit / remove the risk of collusion in the Ripple system the consensus mechanism relies on local Unique Node Lists (UNLs) specific to each node in the network (but potentially provided to the node by a gateway or other third party).

My question is whether these UNLs can be assigned discretionary weights by the user (e.g. if the list comprises A,B,C nodes, can they be weighted 4/6, 1/6, 1/6 respectively)?

If not, would it be possible to include a node several times on the list to achieve such weighting, or do they have to be 'unique' as 'Unique NL' seems to suggest..

(Weighting might be interesting if a large amount of trust is ascribed to one or more particular nodes..)


texts:
When i mine a new block on my pc, how can i broadcast it to other peers, making it included in the blockchain and getting my reward?

Is there any API that provides a function like "sendBlock" or something?

I'm asking it for bitcoin and any other criptocurrency. Ty


texts: Will there be 21 million bitcoins eventually?

texts:
Every x blocks the mining reward is halved. Will the reward be halved forever such that we never quite reach 21 million bitcoins, or will we reach 21 million bitcoins at some point and will the reward cease to exist altogether?

Extra points for pointing to the relevant code!


texts: If Bitcoin were to be used as an alternative, industry-specific banking platform, what would the effect of all 21M bitcoins in circulation be on the dollar/bitcoin exchange rate? Or, would it be better to create some kind of new digital currency specific to that industry while simultaneously creating an exchange for that currency?


texts: Is there a miner with a controllable hashrate?

texts: Sometimes people don't want to mine at a full load due to various reasons (computer noise, hardware concerns, etc). Are there any miners out there in which one can set a hashrate limit? I know one can use -f and -s flags, but the amount of control they give is quite limited.


texts: how to generate bech32/segwit address from pubkey in golang

texts:
I am trying to generate bech32/segwit address in golang with the following code:
var pubkey *btcec.PubKey
address, err := btcutil.NewAddressPubKey(pubkey.SerializeCompressed(), chainParams)
if err != nil {
    log.Fatal(err)
}
address.SetFormat(btcutil.PKFCompressed)
bech32Bytes, err := bech32.ConvertBits(address.ScriptAddress(), 8, 5, true)
if err != nil {
    log.Fatal(err)
}
segwitaddr, err := bech32.Encode("tb", bech32Bytes)
if err != nil {
    log.Fatal(err)
}

and also more simply
var e *hdkeychain.ExtendedKey
address, err := e.Address(chainParams)
bech32Bytes, err := bech32.ConvertBits(address.ScriptAddress(), 8, 5, true)
if err != nil {
    log.Fatal(err)
}
segwitaddr, err := bech32.Encode("tb", bech32Bytes)
if err != nil {
    log.Fatal(err)
}

But neither segwitaddr generated match the bip84 address I got from https://iancoleman.io/bip39/. What is wrong with the code above or how to properly get a bech32 address from a pub key?
I have looked into another post on the same question, but could not figure out how to prepare the data needed in golang. More specifically, I am confused in preparing the input []byte to call bech32.Encode() and using bech32.ConvertBits().


texts: I'm currently trying to generate the genesis block with my code and I've stumbled upon the TxIn sequence field that is not explained in the Protocol Specification wiki page, nor does it seem to appear in the block explorer. What is the way the value of this field is calculated, and what was its value for the genesis block?


texts: Altcoins with plaintext transaction messaging

texts: I'm looking to compile a list of altcoins with plaintext transaction messaging embedded into the blockchain. If anyone knows of a coin that fits the bill then please share.


texts: How much is a mining pool share worth on average?

texts:
I know that mining pool shares have no value on their own, but it should be possible to find an average value based on the pool's average payout per share. This site describes the expected payout per share as ([block reward] - [pool operator's cut]) / [difficulty].

It seems to me that a share's "value" would necessarily be related to the difficulty as set by the pool--a pool with shares that are harder to find will have its users find fewer shares, making each share "worth" more. However, the equation above clearly doesn't work with the pool's difficulty, as most pools set difficulty to 1 and a share isn't worth ~48 BTC. How can I reconcile these issues to calculate the expected payout per share of a pool without knowing how many total shares are found?

Edit:

Ah, I think I've figured it out. The difficulty in the equation can be the network difficulty, because that's what makes it more or less likely that a given successful hash (earning a share) in a pool solves the block and earns the block reward. Thus, the network difficulty indirectly limits the value of a share. Is this correct?

Edit Again:

And now I'm back to being confused. If Pool A sets a higher difficulty than Pool B, Pool A's shares are worth more than Pool B's (assuming the same number of miners at a set hash rate) because they're rarer so each share will earn more at payout. How is this taken into account in the equation?


texts: Can bitcoin transactions be modified during mining

texts:
Wherever I read about fraud in bitcoin, it talks about modified a transaction that is already in a block and changing the receiver and then trying to create a longer chain.

However, I was wondering, if we can modify a transaction thats already in the block, why can not a miner, modify a transaction at the time of mining itself. And if he is lucky, he can find a block that will make the transaction unmodifiable.

PS. Kindly excuse me for such a silly question, as I am a student in bitcoin and blockchain.


texts:
In bitcoin, a blockchain always starts at the unique genesis block. Beyond that point there can be forks, and only when it is clear which branch will grow fastest (or if it has grown enough), we can know for sure (or almost) if a block will end up in the actual blockchain.

Is it necessary to have a genesis block? I could imagine that without, when bitcoin was launched, miners would just have started mining blocks, and as soon as one was mined, the chain would grow from there. If another miner found another block 0, the blockchain could be extended from there as well just as with any other fork (note that this would be equivalent to having an abstract genesis block that doesn't need to have any properties that can be treated as the parent of any block 0).

Is this just an accidental feature of the initial design of bitcoin, or is there a deep reason for the existence of an eternal genesis block?


texts: What is the most efficient and safest way to handle cold&warm Bitcoin storages?

texts:
Think of a situation where you receive and send bitcoins on a regular basis, like an exchange or a payments processor.

You want to keep as large a portion of your coins as possible on the cold storage without compromising efficiency.
You can't store all your coins in a cold storage because you need to send payments regularly too.
You need enough bitcoins on the warm storage to be able to cover the daily outgoing transfers you send.
Sometimes you receive a lot, sometimes you send a lot.
You need a secure and efficient way to transfer coins between these storages.

How do you do this?

Keeping paper wallets in a safe and opening and importing/swiping them into the warm storage just doesn't work after a while.


texts: How segwit blocks are seen by segwit and non-segwit nodes?

texts:
Let's say a miner mines a block.

In this block some transactions will be non-segwit and some will be segwit?
The block contains two parts:

The part with transactions
The segregated part with signatures of segwit transactions?

To old nodes non-segwit transactions look normal, and segwit transactions look like no-signature-needed valid transactions? These nodes don't see the segregated part containing signatures?
To new nodes non-segwit transactions look normal, and they recognize segwit transactions and check the segregated part to validate the signatures?


texts: Why did Bitcoin Core wallet send my coins to this address?

texts:
Yesterday evening I installed the Bitcoin Core wallet (v0.11.2 (64-bit) from the Chocolatey repo to my Windows 10 machine). I had some coins in an old wallet.dat that I copied to the data directory. That worked fine. While the Blockchain was downloading, I transferred the balance from the old wallet to a new address (in my MultiBit HD wallet): 1JRyKhLLXMeVPpeEw3fvcJbUmrZYtRiojd.

Bitcoin Core wallet created a new transaction to that address in the transaction list. Unfortunately, a few seconds later, it also created a new transaction with the same amount, but to an unfamiliar address: 1Msx9dp6uVr1rrz6pUxXwqLL3oxB9fDn1j.

This new transaction was soon confirmed, while the transaction I entered remains with status Conflicted.

Here's (the relevant part of) the transaction list in Bitcoin Core wallet:

Here's the transaction I asked Bitcoin Core wallet to create, and the mystery transaction it created on it's own initiative:

What could have happened here? Is there any way I can find the PK for the mystery address (could it be a change address in the wallet or something like that)?


texts: Block Hash and Nonce generated by GenesisH0 python script is incorrect

texts:
After running GenesisH0 python script to generate the Genesis block for a local testnet (using v0.15.1), I got the following results.

merkle hash: 09a3e8eee58b90dba48f458a5e6bc04359b3630bbebdd5289c11818c756d5417

pszTimestamp: Yahooo 02/Feb/2018 SUV's accelerator sticks at speeds up to 100 mph

pubkey: 04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f

time: 1518480000

bits: 0x1d00ffff

nonce: 3318186986

genesis hash: 0000000007783526b2049ea1ce5720e6f7486a9bb48a60bb2e93b892dd229984

When placing this information in chainparams.cpp and running the bitcoind after compiling it failed. The nonce produced by the script produces a different block hash when CreateGenesisBlock is executed.

Does anyone know why this script no longer works to create the genesis block for version v0.15.1?


texts:
There is a lot of criticsm and debate over whether bitcoins will ultomately fail because of its deflationary nature.

I don't want to debate if that's the case or not and I also understand that the goal of bitcoin was to have a fixed amount of coins so that there is no risk of (hyper)inflation.

What I'm wondering is, would it be technically possible for a crypto currency to have a fixed target inflation rate? For example the european central bank has a target inflation rate of 2% (I think) which is supposed to stimulate growth while at the same time avoiding over-inflation.

So I guess my question boils down to: Why are all popular crypto currencies deflationary? Is it a technical problem that cannot be solved or is there another reason it was designed like this?


texts: Were all funds stolen from Mt. Gox finally returned to all users?

texts:
Mt. Gox was hacked in June 2011, and some funds were stolen. There was a long winded account reclaim process.

At the end of this process, were all funds really returned to the satisfaction of all (legitimate) users? Is there a public statement / forum post that testifies to this?


texts:
I am trying to understand the unlocking portion of the transactions inputs of this pay-to-public-key-hash transaction: https://www.blockchain.com/btc/tx/0627052b6f28912f2703066a912ea577f2ce4da4caa5a5fbd8a57286c345c2f2
Pasting the following unlocking+locking portion into bitcoin IDE:
3045022100884d142d86652a3f47ba4746ec719bbfbd040a570b1deccbb6498c75c4ae24cb02204b9f039ff08df09cbe9f6addac960298cad530a863ea8f53982c09db8f6e381301
0484ecc0d46f1918b30928fa0e4ed99f16a0fb4fde0735e7ade8416ab9fe423cc5412336376789d172787ec3457eee41c04f4938de5cc17b4a10fa336a8d752adf
OP_DUP
OP_HASH160
7f9b1a7fb68d60c536c2fd8aeaa53a8f3cc025a8
OP_EQUALVERIFY
OP_CHECKSIG

Shows me the OP_HASH160 results in a public key hash of
0x6DF13DE1F1D824380834E0D42E49E5E451A647CF

But for this script to pass the OP_EQUALVERIFY it should be
7f9b1a7fb68d60c536c2fd8aeaa53a8f3cc025a8

This transaction is valid. What am I  misunderstanding?


texts:
Old standard transactions format included 3 types: P2PUBKEY, P2PKH, P2SH. After Segwit soft fork, we have got 2 additional types: P2WPKH and P2WSH.

If we compare the cost of spending inputs (in bytes we write on HDD) for   P2PUBKEY, P2PKH, and P2WPKH and  we got next values:

P2PUBKEY  33 bytes public key(we do not consider uncompressed keys)  + signature 72 bytes = 105 bytes
P2PKH        20 bytes public key hash + 33 bytes public key + 72 bytes signature = 125 bytes
P2WPKH     20 bytes public key hash + 33 bytes public key + 72 bytes signature = 125 bytes

From this comparison, we can conclude that P2PUBKEY the best for reducing blockchain size. We can save about 19% of spending input size. I understand that P2PKH give more
security in case we do not reuse the address. If we reuse address, there are no advantages to use P2PKH. We can observe the quite frequent use of addresses repeatedly. For a specific range of tasks, we do not need extra security like P2PKH. Why in Segwit transaction types we don't have the ability to use P2WPUBKEY as standard transaction?  This type of transaction help to reduce blockchain size in case a user does not need/want use "no address reuse" security model? 20 bytes for each input this is a good opportunity to save the size of the blockchain.

Also, I read this thread https://bitcointalk.org/index.php?topic=6430.0, what is the reason why bitcoin core developers do not want to use public key recovery and save 33 bytes for each input?  If the concerns are related to performance, we can observe how the ethereum works and reaches about 1M tx per day (this is like 1M inputs per day in Bitcoin).


texts: What is the math behind a private key BASE58 (P2PKH)

texts:
Using this link I can understand something about a private key BASE58 (P2PKH):
"such encodings will always yield a 51-character string that starts with '5', or more specifically, either '5H', '5J', or '5K'."
So let's say I have this model of private key:
5J1111111111111111111111111111111111110111111222222
I know that is not a valid private key because I can use a website such as bitaddress to tell me about this.
Taking a private key like this, I would like to understand how I can verify if it is valid, what the procedures are, because I would like to write a script to play around with this.
Keep in mind I don't have any other information, just a string like that.


texts: Is there a simple method of tracking number of transactions sent to an address?

texts:
I want to create a counter in my store displaying the number of units sold.

I'm not using a shopping cart, but simply placing a bitpay button.  I'm wondering if there is a way to query the blockchain, that will return the number of transactions sent to an address, over a given time period.


texts: developing a new alt-coin useful or not?

texts:
I will try just for educational purposes create my alt-coin. But i have some
questions before to start.

It's possible create the alt-coin since my ubuntu and maintain this alt-coin since my pc if its always turn on?
My last question, at this moment is possible that this new altcoin get some real price in the market?

Someone can guide me a little or say me if will be useful in something create a new alt-coin? And maybe can get be profitable?


texts: Canadian bought BTC on cex.io in USD - how do I deal with them to not lose money with CAD-USD exchange rate?

texts:
I'm a single mom and was gifted some cash that I decided to try and "invest" haha, in bitcoin and other coins.

In my haste to purchase, I signed up for cex.io and funded with my credit card - so I got $300 USD but paid $409 CAD --- I used that USD to buy Bitcoin.

Then I realized the exchange rate killed me - or did it?

I am now using QuadrigaCX (duh, it's Canadian!) but I still have the coins I bought in USD on cex.io ($900 worth but paid like $1230 CAD)

My question is - do I transfer my BTC to my Canadian exchange...

do I hold them in the USD cex.io until I want to sell them,
or what??

I feel so silly, like I paid an extra $100 by forgetting about the CAD to USD exchange rate.

Any help or advice greatly appreciated!


texts: Understanding Transactions, Mining, and the 10 minutes block solved

texts:
I'm not entirely sure if the questions I have regard to Bitcoin all relate to each other?
How do miners decide how many transactions they should have in a block in order to mine 1 bitcoin? When miners compete to find the "nonce" that has the smallest possible hash number, would it be faster/easier to find the "nonce" if there are fewer transactions? Or do miners try to pack as many transactions (up to 1 mb of data) into a block so they can get the most fees?
Do all miners try to solve a solution where all the transactions should be the same in a single block and everyone's trying to compete to finding the nonce and hash? Or is it random, and its just whoever finds a hash the quickest, saves those transactions and adds it to the blockchain?
Also, I noticed looking at btc.com, there are blocks being mined less than 10 minutes back to back, I thought it needs to be 10 minutes to be mined?


texts: Should I always run "make clean" between building different PR branches of Bitcoin Core?

texts:
I am switching between building different PR branches (ie I built one PR author's branch and now I am building a different PR author's branch).
Jon Atack's doc suggests:

On the other hand, when you change the build configuration, and in some cases when testing different PRs, or when the build isn't working, it's often best to start with a clean slate using make clean or make distclean before configuring.

Should I always run make clean in between builds?
edit: Jon Atack has since updated his doc. Here is the updated guidance.

On the other hand, when you change the build configuration (e.g. for a fuzz build), or you are building a branch containing substantial changes to the autoconf/automake scripts, or when the build isn't working, it's often best to start with a clean slate using make clean or make distclean.


texts:
I've been struggling the past couple of days to deserialize a merkleblock message. I'm writing a go app that uses the bitcoin rpc client to call gettxoutproof, but only need the merkle proof (array of required tx hashes needed to hash merkle root) of given transaction (want to verify the transaction in an ethereum smart contract).

So I've looked at how the serialization is defined in merkleblock.h which looks pretty straight forward. The problem i'm having is figuring out how CDataStream serializes the CMerkleBlock object, and finding the transaction hashes in the hex string.

Example:
This is the block im looking at: Testnet Block

it only contains one tx: 8148740e33df53073f55089f195c327f40e2a9c374dcc05643c60671243cc4a8

When I run the gettxoutproof command I get the following output:

0000002024ea1b7676f6ae9f2a3b639ec43e15c509a661d33d123deb3d00000000000000a8c43c247106c64356c0dc74c3a9e2407f325c199f08553f0753df330e744881f4d6715affff001d00cecafd0100000001a8c43c247106c64356c0dc74c3a9e2407f325c199f08553f0753df330e7448810101

Initially I expected to find the tx hash somewhere in that hex string, since its the only tx in the block and has to be included, but its no where to be found. Since the docs say that gettxoutproof returns a serialized, hex encoded string I thought maybe the tx hash has been hex encoded, but it isn't.
I've tried figuring this out with other blocks, that for example contain 2 transactions but have had no luck. I've looked at how CDataStream serializes the data but fail to understand it.

Would be very happy if someone could help me out!


texts: Can Buy Bitcoin From Different country exchange and transfer to wallet

texts:
Completely new to this I want to know that,

If I purchase bitcoin from exchange website https://bitcoin.org/en/exchanges any country Then I can transfer it to Zebpay wallet.

Because it looks good deal price is not same everywhere just transaction fee if you purchase in volume then this seems nothing.
I'm new here many peoples already tried this or may be I'm getting it wrong.


texts: Can replay transactions effect both chains? or just the minority hard fork chain?

texts:
Can a seg2x transaction be replayed on the main bitcoin CORE chain?

I was reading that only the minority hard fork would need replay protection and that coins on the main majority chain would be safe


texts:
In a transaction Tx, the hash pointer of the earlier transaction (say TxE) that serves as input to Tx must be signed by the sender S of Tx. This is to show that S was the recipient of TxE.
It remains to show that S agrees with the output of Tx. At which stage does S sign the output of Tx?
I assume (s)he does so. Else, what would prevent an attacker from looking at Tx just after S broadcasted it, and modify the output (so that he is the recipient) before rebroadcast?

In other words:
The scriptSig proves the sender owns the input of Tx. What proves that the sender approves the output of the Tx?

rgds

P.S: the transaction I am considering atm is:


texts:
I know what Bloom Filter (BF) is, and I'm aware of this post and this paper. But I don't understand how it's used in bitcoin.

I can imagine that an SPV node encodes the transaction(s) it's interested in, into a BF and sends it to full node. What I don't understand is that what does the full node do after that?

Does it traverse through all the previous transactions and check which one is in the BF and sends it to the SPV node?

Also, it's not clear how private the approach would be, because at the end the full node retrieves what the SPV node wants and sends it to the node, so it knows what it's interested in.

If the goal is to preserve the privacy of the SPV's query, then some sophisticated approaches such as private information retrieval or oblivious ram must be used but they are not efficient for the bitcoin setting.


texts:
I'm giving a specific case here, but I think I have seen the same error trying to use stratum_proxy for any pool and coin I have tried.

When wemineltc.com briefly had a getwork server up, cudaminer worked great! But now that they're back to stratum only, I'm trying to get that to work.

I run the stratum proxy that I get from wemineltc and see this:

C:\dev\cudaminer-2013-04-14\stratum_proxy.exe\twisted\web\util.py:372: Deprecati
onWarning: Passing filenames or file objects to XMLFile is deprecated since Twis
ted 12.1.  Pass a FilePath instead.
2013-04-16 08:24:07,302 WARNING proxy jobs.<module> # C extension for midstate n
ot available. Using default implementation instead.
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Stratum proxy version: 1.
3.0
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Trying to connect to Stra
tum pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Setting PoW algo: scrypt
2013-04-16 08:24:07,621 INFO stats stats.print_stats # 1 peers connected, state
changed 1 times
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Connected to Stratu
m pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Subscribing for min
ing jobs
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # PROXY IS LISTENING ON ALL
 IPs ON PORT 3333 (stratum) AND 8332 (getwork)
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy client_service.handle_event # Setting new dif
ficulty: 128
2013-04-16 08:24:07,839 INFO proxy client_service.handle_event # New job c9 for
prevhash d2c7e1c2, clean_jobs=True

Then I run cudaminer with the following batch file (on windows 7 64 bit):

cudaminer.exe -o 127.0.0.1:8332 -O user:password

And see this:

C:\dev\cudaminer-2013-04-14>cudaminer.exe -o http://127.0.0.1:8332 -O user:
password
           *** CudaMiner for nVidia GPUs by Christian Buchner ***
                     This is version 2013-04-14 (alpha)
        based on pooler-cpuminer 2.2.3 (c) 2010 Jeff Garzik, 2012 pooler
               Cuda additions Copyright 2013 Christian Buchner
           My donation address: LKS1WDKGED647msBQfLBHV3Ls8sveGncnm

[2013-04-16 08:29:52] 1 miner threads started, using 'scrypt' algorithm.
[2013-04-16 08:29:52] HTTP request failed: The requested URL returned error: 401

[2013-04-16 08:29:52] json_rpc_call failed, retry after 15 seconds

I have tried a few different things but I always get that 401 error. Any ideas on resolving this?


texts: Is the new Google Compute Engine suitable (and affordable) for running a bitcoind instance?

texts:
Google just recently (at Google I/O 2012) announced their new cloud product, the Google Compute Engine. I don't really understand what it is exactly but I heard it's basically some sort of VPS service.

So I was wondering if it would be suitable for running a Bitcoin client for a web application. I don't know what resources are required for running such, either do I know what prices you get when doing so in Amazons platform. Google says Compute Engine's pricing gives you the same computation power for half the price of competitive products, but I cannot really compare.

Did anyone made this consideration as well? Did anyone take a closer look at this?


texts:
Can anyone recommend any open source code for bitcoin wallet or any bitcoin applications or clients?

please posts links or samples of it.

thank you


texts:
New to using BTC and the Blockchain.

My understanding is that (for the Bitcoin), one can download/install btcd.

Then, one has to use btcd to synchronize the "local" Blockchain with the "main" Blockchain(?)

If so, what is the best API that one can use to access the data in the Blockchain?

I saw this:
https://en.bitcoin.it/wiki/API_reference_(JSON-RPC)

For example, I have seen blockchain.info - but - I am not sure that one can download this and have it "point" to one's local btcd.

Any suggestions, help or hints would be greatly appreciated.

TIA


texts: How to Reset Dragon Miner 1TH/s IP Address?

texts:
How can I reset the IP address of a Dragon Miner 1TH/s machine?

Mistakenly, I entered the wrong IP in the miner when changing the network IP address, and now my miner is not visible on the network. What I entered was like "IP 192.168.1.100.4".

So how can I reset my miner?  It has the SD card option.


texts:
I'm running a full node (v0.16.0).  I added txnindex=1 to my configuration file and restarted the Bitcoin-Qt. It took 2+ days to build the index but when I check addresses with known final balances>0 the amount is still zero. For example...

REMOTE FINAL BALANCE=66.76870249 BTC:

https://blockchain.info/address/1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa

LOCAL FINAL BALANCE=0:

let address='1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa';
client.getBalance(address, 6, function(error, balance, resHeaders) {
log('Address: ' + address + ' Balance:'  + balance);
});

Any ideas would be appreciated!


texts: Accepting 0-confirmation transactions and detecting double-spends with open source solution

texts:
I would like to accept 0-confirmation bitcoin for very small amounts. I am happy to accept zero-confirmation spends and am aware of the risks. However, the tool needs the ability to "flag" the accepted transaction/s if a double-spend is detected. I can then decide what action to take.

I do not want to use a centralized third-party tool. I would like to use something locally on the server. It would simply display pre-generated public addresses. No need for private keys and/or seeds to be on the server.

Does such a tool exist?

Thank you.


texts: retrieve all the transaction between two addresses

texts:
I've used this query to try to get all the transaction between two addresses:

https://blockchain.info/multiaddr?active=1EipJdYVJbqsTSQhj1icK424AkMbyjvgBm|1LWwLvKWbcpiZYqCcwfuQ3gjjNJkxftmEJ

but the thing is- according to my wallet there are many more transactions that aren't appearing in the json result here.

Why is that?

How can I see actually all of the transactions?

I though maybe blockexplorer would be better than blockchain.info, but actually- not so.

They have it as this:

https://blockexplorer.com/api/addrs/1EipJdYVJbqsTSQhj1icK424AkMbyjvgBm,1LWwLvKWbcpiZYqCcwfuQ3gjjNJkxftmEJ/txs?from=0&to=50

perhaps it would be better to just query by txid?


texts: How do exchanges provide wallets unique wallets to users but also keep transaction fees low?

texts:
So I understand that exchanges don't have to perform updates on the blockchain. However I'm not sure how they figure out the following solution without having to pay blockchain fees? I guess they do
i.e.

An exchange gives 3 users, Bill, Jane & Sally a BTC address.
Bill & Jane both send in 0.001 BTC to that address from a different exchange/wallet.
Now Bill & Jane both send 0.0005 BTC to Sally on the same exchange. Same exchange so this doesn't have to be on the chain.
So now Bill & Jane both have 0.0005 BTC and Sally has 0.001 BTC according to the exchange. However both Bill & Jane's actual wallet address still has 0.001.
Sally now withdraws her 0.001 BTC

The exchange now needs to perform two blockchain updates to fulfill this withdraw which means two transaction fees on the blockchain for the exchange.
Does anybody know how exchanges do this?


texts: How to find Values N and K given R,S and Z in ECDSA?

texts:
How to find Value N and K ? I have the values for R, S and Z.

for example these:

BigInteger R =("00d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1"));
BigInteger S =("0044e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e"));
BigInteger Z =("00c0e2d0a89a348de88fda08211c70d1d7e52ccef2eb9459911bf977d587784c6e"));
BigInteger X  =("00c477f9f65c22cce20657faa5b2d1d8122336f851a508a1ed04e479c34985bf96"));

Now, how to get these:

BigInteger K =("007a1a7e52797fc8caaa435d2a4dace39158504bf204fbe19f14dbb427faee50ae"));
BigInteger N =("00FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141"));

How to get the values K and N ?
I am confused about how to calculate it, can somebody tell me how it is done?


texts:
Okay so I have done my research, I have practically tried everything. It just frustrates me because mining LTC was a piece of cake but I can't seem to figure out how to mine bitcoins which this device says it can do bitcoins plus dual mining.

I have tried BFGminer but it seems not to detect my gridseed unless I am mining LTC. Then I tried CPUMiner and it works except it gets invalid all the time its like its using the wrong algorithm but I tried the -a sha256d and still produces the same issue. Can somebody help me I have the drivers installed and my usb Gridseed miner is on COM6. I have also tried CGMiner and it says cannot detect any USB devices.

I have tried every possible thing that comes up on the first few Google Results. I am not exactly new to mining as I have done Scrypt mining fine with this device.

Here is the product.


texts:
I'm trying to figure out the size of the block

and i have trouble calculating the number of bytes of time

one block has time like this:
"time":1516430234

After counting the bytes, the value is :5

This is a mistake, since it should be only 4

Does anyone know the solution?


texts:
In Bip44 "Account Discovery" section, there is following sentence:

  We scan just the external chains, because internal chains receive only coins that come from the associated external chains.
  (https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki#address-gap-limit)

I do not understand it. If I do not scan internal chain, how will I find the change addresses?
Yes, change address will exist in transaction output of public (external) addresses, but I can not find out which output address is change address as it can be real receiver address.
Thanks for help.


texts: Are there ready-to-use indexed bitcoind data files available somewhere?

texts:
I tried bootstrapping bitcoind, but it's slowly downloading and downloading. I tried putting these files first, but it is still downloading something a bit, stays 100% CPU, iowaits, fills up the thawing free gigabytes and is not going to finish soon.

Is there somewhere ready-to-use $HOME/.bitcoin directory available for download to skip any lengthy initial phase?


texts: When ipv6 is enabled my ipv4 address does not appear in getnetworkinfo localaddresses

texts:
After enabling ipv6 (Google WiFi/Ubuntu 16.04) I noticed that my node's upload bandwidth dropped a lot.  Investigating showed:

ifconfig lists one ipv4 address and three ipv6 addresses.
bitcoin-cli getnetworkinfo lists zero ipv4 addresses and two ipv6 addresses and one tor address.
in getnetworkinfo the only address with a score greater than 1 is my tor address.
debug.log shows the discovery of both ipv6 addresses and the tor address.
debig.log also shows the lines Bound to [::]:8333 and Bound to 0.0.0.0:8333

Everything seems in order from the logs and ifconfig but I can;t figure out why bitcoin-cli does not list my ipv4 address.  I am assuming that is why I'm not serving many historical blocks (my node used to serve 50 Gb a day and now hovers around 1Gb which I assume is the tor interface.)

Any advice is welcome!


texts: What role has bitcoin-init as a process?

texts:
I have set up a node on a RaspberryPi. When I check for active processes with top I see bitcoin-init occupying 50% of memory and 7% of CPU.

I can check for bitcoind and it is active:

bitcoin@raspberrypi ~ $ service bitcoind status
● bitcoind.service - Bitcoin daemon
   Loaded: loaded (/etc/systemd/system/bitcoind.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2019-08-09 14:43:54 CEST; 2 weeks 4 days ago
  Process: 623 ExecStart=/usr/local/bin/bitcoind -conf=/home/bitcoin/.bitcoin/bitcoin.conf -pid=/home/bitcoin/.bitcoin/bitcoind.pid (cod
 Main PID: 772 (bitcoin-init)
    Tasks: 16 (limit: 4915)
   CGroup: /system.slice/bitcoind.service
           └─772 /usr/local/bin/bitcoind -conf=/home/bitcoin/.bitcoin/bitcoin.conf -pid=/home/bitcoin/.bitcoin/bitcoind.pid

According to this thread I assume that the daemon process bitcoind
has been renamed to bitcoin-init but I am not sure if I understood that correctly.

My node seems to update the chain, but very slowly - 50GB after several weeks. And it is not reachable if I check my local IP via Coindance.

If I run bitcoin-cli getinfo with my usual Rasperry user pi I get

error: Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set.  See -rpcpassword and -stdinrpcpass.  Configuration file: (/home/pi/.bitcoin/bitcoin.conf)`

I have not set up a bitcoin.conf file.

If I run it with user bitcoin (not sure if that would be the right thing to do):

bitcoin@raspberrypi ~ $ bitcoin-cli getinfo
error code: -32601
error message:
Method not found

So, is bitcoin-init maybe just a startup process and my node is not working?

EDIT: The book (Antonopoulos) sais that bitcoind will give an error unless I set an rpcpassword in the configuration file. I don't have such a file, but bitcoind gives:

2019-08-28T07:27:16Z Bitcoin Core version v0.18.99.0-12fd4bbd1 (release build)
2019-08-28T07:27:16Z Assuming ancestors of block 0000000000000000000f1c54590ee18d15ec70e68c8cd4cfbadb1b4f11697eee have valid signatures.
2019-08-28T07:27:16Z Setting nMinimumChainWork=0000000000000000000000000000000000000000051dc8b82f450202ecb3d471
2019-08-28T07:27:16Z Using the 'standard' SHA256 implementation
2019-08-28T07:27:17Z Default data directory /home/pi/.bitcoin
2019-08-28T07:27:17Z Using data directory /home/pi/.bitcoin
2019-08-28T07:27:17Z Config file: /home/pi/.bitcoin/bitcoin.conf (not found, skipping)
2019-08-28T07:27:17Z Using at most 125 automatic connections (1024 file descriptors available)
2019-08-28T07:27:17Z Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements
2019-08-28T07:27:18Z Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements
2019-08-28T07:27:18Z Using 4 threads for script verification
2019-08-28T07:27:18Z scheduler thread start
2019-08-28T07:27:18Z Binding RPC on address ::1 port 8332 failed.
2019-08-28T07:27:18Z Binding RPC on address 127.0.0.1 port 8332 failed.
2019-08-28T07:27:18Z Unable to bind any endpoint for RPC server
2019-08-28T07:27:18Z Error: Unable to start HTTP server. See debug log for details.
Error: Unable to start HTTP server. See debug log for details.
2019-08-28T07:27:18Z Shutdown: In progress...
2019-08-28T07:27:18Z scheduler thread interrupt
2019-08-28T07:27:18Z Shutdown: done

EDIT: I seem to have two seperate directories for .bitcoin. How can I tell bitcoind to use the other one?


texts: Bitcoind information about the input and output

texts: Im trying to get the wallets/accounts the money got sent to. But getrawtransaction does not give any information about the reciever or sender


texts: How to get balance by any address using rpc bitcoind?

texts:
How to get balance of any address using rpc bitcoind?

I mean getting by address the list of his unspent outputs in view something like this: TxHash;Value;Noutput.


texts: Do Bitcoin calculators give a realistic figure on pool mining

texts: Bitcoin calculators give an approximate correct range reward for solo mining, do they include pools, accounting your Hash rate reward share. I have not seen any pool calculators around, nevertheless their incomprehensible reward systems.


texts: What's the difference between synced_blocks and synced_headers?

texts:
My P2P is a bit rusty, but as far as I understand; if we're running a full node, other nodes will connect to us to share blocks. So I can see why it would be useful to be able to see how far behind other nodes's blockchains are with the getpeerinfo command.

However, what's the practical difference between synced_headers and synced_blocks?

For example, what does it mean if a peer has synced_headers equal to the height of our own blockchain, but a synced_blocks of -1?


texts:
I read that the private key pk has to be any number between 1 and n, where n is almost 10^77.
Since pk' s function is practically to be used as a scalar for multiplying the generator point G, why does it have to be strictly less than n?

I've thought that is because the math behind secp256k:
inside a order-n group, if I multiply times x a number A (with x > n), it's equivalent to multiply the same number A times y, with y =  x % n. So y will be extremely less than x, making A easier to be discovered.
Is this argument correct?


texts: Multibit is not accepting the correct password any idea or possible bugs that i could fix

texts:
just what i said. Multibit simply isn't accepting the password i used this morning to unlock it.

i have tried retyping it about a million times in a million different way.

does any one have any insight on this? it there a way to import the wallet into a different program and de-crypt it there?


texts: Possibility of contructing a valid transaction without knowning private key

texts:
From here you get that in step 2 of ECDSA sign process, you use
z, the Ln  leftmost bits of e = HASH(message/transaction) in both the process of generating and verifing the signature.

I understand that in bitcoin transactions signature and verification you do almost the same algorithm.

So...

You know that adress A has a transaction x to it that values in 1 BTC not spent.

You know also a transaction y1 from A with a certain signature and a certain value z1, as the algorithm in the link says.

Could you create a transaction y2 so that it sends the 1 BTC from A to adress B by creating it in a way that it had the same z1 (mentioned above) and consequently the same signature of y1? (since signature depends only on message (z), private key and the random value k)

This transaction y2 would be valid?


texts: Double signature requirement of Breach Remedy Transaction

texts:
In the Lightning Network Paper (https://lightning.network/lightning-network-paper.pdf), Breach Remedy Transactions seem to require signatures by both channel members. I infer this from this description in the paper:

  When a new pair of Commitment Transactions (C2a/C2b) is agreed upon,
  both parties will sign and exchange signatures for the new Commit-
  ment Transaction, then invalidate the old Commitment Transaction. This
  invalidation occurs by having both parties sign a Breach Remedy Trans-
  action (BR1), which supersedes the Revocable Delivery Transaction
  (RD1). Each party hands to the other a half-signed revocation (BR1)
  from their own Revocable Delivery (RD1), which is a spend from the
  Commitment Transac- tion. The Breach Remedy Transaction will send all
  coins to the counterparty within the current balance of the channel.

(Emphasis by me.)

I do, however, not understand why this is a requirement. It seems to me that it's possible to design the Revocable Sequence Maturity Contract in such a way that only the signature of the Breach Remedy Transaction's issuer is required, not additionally the one of the redeeming party.

Is my notion correct? If not: Why not?


texts: Transfer amount on blockchain larger than was sent from wallet

texts:
I sent some BTC from a hardware wallet last year.
The wallet shows a sent amount of 0.09302 BTC but when I look at the transaction id on blockchain.com it shows two amounts.

0.282 BTC unspent and 0.0924 BTC spent

Where has the 0.282 BTC come from was someone elses transaction somehow included with mine?

ea0be0433c3a0869aa62ff025abd33d5a400f51835f05c87f844d0e8158be0aa


texts: Unbreakablecoin - Block Height Stopped Moving

texts:
I am running a full Unbreakablecoin (a Bitcoin clone) node.

Blocks were being generated every few minutes or so, until about a week ago. Now, the block height has been stuck at 82666 for multiple days. Also and all peers seem to have one thing in common: They have some reference to a single IP address of 71.71.215.6

Is this some sort of hack/attack? If yes, how is it being accomplished?

~ unbreakablecoin-cli getpeerinfo

[
    {
        "id" : 111,
        "addr" : "198.27.81.114:54022",
        "addrlocal" : "71.71.215.6:9336",
        "services" : "0000000000000001",
        "lastsend" : 1515125911,
        "lastrecv" : 1515125911,
        "bytessent" : 51777,
        "bytesrecv" : 52217,
        "conntime" : 1515032269,
        "pingtime" : 0.11530600,
        "version" : 70002,
        "subver" : "/Satoshi:0.10.3/",
        "inbound" : true,
        "startingheight" : 82666,
        "banscore" : 0,
        "synced_headers" : 82666,
        "synced_blocks" : 82666,
        "inflight" : [
        ],
        "whitelisted" : false
    },
    {
        "id" : 116,
        "addr" : "173.208.145.82:55264",
        "addrlocal" : "71.71.215.6:9336",
        "services" : "0000000000000001",
        "lastsend" : 1515125940,
        "lastrecv" : 1515125940,
        "bytessent" : 50453,
        "bytesrecv" : 51159,
        "conntime" : 1515033251,
        "pingtime" : 0.14900100,
        "version" : 70002,
        "subver" : "/Satoshi:0.10.3/",
        "inbound" : true,
        "startingheight" : 82666,
        "banscore" : 0,
        "synced_headers" : -1,
        "synced_blocks" : -1,
        "inflight" : [
        ],
        "whitelisted" : false
    },
    ...
    ALL PEERS HAVE "addrlocal" : "71.71.215.6:9336"
    ...
]

~ unbreakablecoin-cli getblockchaininfo

{
    "chain" : "main",
    "blocks" : 82666,
    "headers" : 82666,
    "bestblockhash" : "00000000000000010aacfc4d82170ae9e57854852f30f62d63393a64cab8d4b8",
    "difficulty" : 2079545789.81736517,
    "verificationprogress" : 0.89795278,
    "chainwork" : "0000000000000000000000000000000000000000000003a36f3a84fc39816ff7"
}


texts: How do I exchange Bitcoin for IOTA?  What's the best venue through which to secure IOTA ultimately as my end goal? Since that other company (it seems I cannot name them here) no longer works with US citizens, who do I interface with now?


texts: Test network completely removed from the real network?

texts: I know of the testnet Bitcoin provides, but is there any framework or simulator of the Bitcoin network which I can use to test on my local machine? I would like to edit parts of the code and simulate the responses of the real network without actually interacting with it.


texts: when will the bitcoin wallet app be available for windows phone?

texts: I've been wondering because i just bought a windows phone and realized it doesnt have  the wallet app. any idea when windows phone will get the wallet app?


texts: What are the factors affecting expected difficulty and what is the maximum value it can take over the period of 30 days?

texts:
Lets take for example day 1 difficulty of 300MM. What is the mechanism to determine the rise in difficulty?
What is the maximum value it can go starting from that number and expecting the biggest possible rise over 30 days?


texts:
I try to enter in my copay vallet and the screen turn white. What should I do I am from Argentina I try but I can make to function again. I try to formated the cell phone but it does not work

Thanks


texts: How to setup testnet-in-a-box on Mac OSX?

texts:
I'm trying to setup testnet-in-a-box and I'm a little unclear on how you get the command line version working for mac as described here:

http://sourceforge.net/projects/bitcoin/files/Bitcoin/testnet-in-a-box/

I installed macports and ran sudo port install bitcoin so I have a bitcoind executable now.

Instead of

bitcoin -datadir=1 -daemon
bitcoin -datadir=2 -daemon

Do I just use?

bitcoind -datadir=1
bitcoind -datadir=2

Also, since there are two nodes do they have to run on different ports?  Thanks


texts: Why did the core developers choose base64 for PSBT encoding?

texts: Why does bitcoind use baase64 to encode PSBT's? Just out of curiosity.


texts: Finding Transactions with seldom used opcodes for testing

texts:
I'm trying to implement a script evaluator and would like to get some real testing data from the blockchain (testnet or mainnet). Are there transactions whose input scriptSigs combined with the previous transaction's scriptPubKey use any/all of these op_codes? I'd like to compile a collection of such transactions as test vectors.

98: op_ver,
101: op_verif,
102: op_vernotif,
107: op_toaltstack,
108: op_fromaltstack,
109: op_2drop,
111: op_3dup,
112: op_2over,
113: op_2rot,
114: op_2swap,
115: op_ifdup,
116: op_depth,
119: op_nip,
120: op_over,
121: op_pick,
122: op_roll,
123: op_rot,
125: op_tuck,
139: op_1add,
140: op_1sub,
143: op_negate,
144: op_abs,
146: op_0notequal,
147: op_add,
148: op_sub,
154: op_booland,
155: op_boolor,
156: op_numequal,
157: op_numequalverify,
158: op_numnotequal,
159: op_lessthan,
160: op_greaterthan,
161: op_lessthanorequal,
162: op_greaterthanorequal,
163: op_min,
164: op_max,
165: op_within,
168: op_sha256,
170: op_hash256,
171: op_codeseparator,


texts:
This is a problem that gets worse every time I do a BTC transaction with Electrum - I have a transaction being held hostage in unconfirmed status for for 3 days now, despite paying a fee a multiplier of .65% (the site suggested .50). I used Electrum several times a week for over a year and this never happened - now, the last 3 or 4 transactions have been beset with these kind of b.s. hangups.

Anyway, last time I dumped another transaction into the queue and it seemed to shake loose the one that was stuck. Thinking it would work again, today
I exchanged $250 USD for (at least according to the receipt) $215 of BTC but after entering them into Electrum, it came out to $117. I called "support" at Cottonwood (vendor for the Satoshi ATM I use) and they had no idea why but could only suggest spending over $500 to get a better rate of exchange. (Right, hit me again, I'll stand real still.)

And despite the fact that Block chain has it marked confirmed, I can't send any more than .0009

This is getting to be a regular thing with Electrum - it used to take an hour from start to finish, now it takes a week and it seems to cost twice as much as before which was outrageous to begin with.  I've uninstalled and reinstalled and refreshed and changed servers so many times in Electrum there aren't any more options available with no luck. Other than the fact that it's clearly time to switch wallets, is this disconnect happening on my end? Thanks.


texts: Why Coinbase hot wallet showing insane price that BTC didn't reach for the day?

texts:
I m bit suspicious about Coinbase service. It shows the current BTC is 16900 USD but in Bitfinex is 15 326 USD.

The worst part is I selected buy BTC from Coinbase its showing 17686.50 USD. How on earth such price variance?

I raised the complaint to Coinbase no answer from them, I felt bit dodgy about their service.

I felt discouraged to use mobile wallet they are not providing the correct exchange rate. Could someone can suggest me best way to buy BTC and move to other wallets?


texts: What are some of the proposed ideas to why the Bitcoin dropped to sub $400 in the end of summer 2014?

texts:
Having seen that BTC was around $600 early summer of 2014 (May-July). It is currently almost 50% of that value. I read many varying reports of the cause of such a big drop.

Can someone give a list of the main proposed ideas of this big drop in price?


texts: How to get the pool name from coinbase transaction?

texts:
Is it possible to retrieve the name of the pool that mined a block looking at the address in the coinbase transaction?

For example, the address in the coinbase transaction of block 00000000000000000002dce191b529017edae3c76d91ab21f757d156daebf43f is: 1KFHE7w8BhaENAswwryaoccDb6qcT6DbYY.
From Blockchain Explorer, that block has been mined by F2pool.
Is there a way to associate F2pool with 1KFHE7w8BhaENAswwryaoccDb6qcT6DbYY?


texts: Difference in hash rates between Bitcoins and Litecoins calculation

texts:
I recently discovered the Hash rate of my graphic card is different with Bitcoins than Litecoins. I understand this is due to the difference in the algorithm. Bitcoin has a double sha256 instead of Litecoins.

If I have a Miner of 1THash/s at Bitcoins what will be the average hash rate I get on calculating the Litecoins?


texts: Generating a Bitcoin Address QR code with current USD price embedded?

texts:
I'm creating a Bitcoin QR link with my website, but I want to be able to just link to a page that generates the QR code with the current USD price equivalent of BTC in the QR. I tried blockchain.info, but it only displays the QR code and I can't embed a price into it. How can this be done? I'm trying to use it on checkout where I can pass in a BTC address + USD price to the QR code generator and the user can just pay the exact amount needed without having to lookup how much to pay.

I know bitpay does this, but they also log every transaction to the government. So I rather just use a service that doesn't log anything.


texts: bitaddress.org: is the public key the same as the Bitcoin address?

texts: For paper wallets generated at bitaddress.org, are the public keys and BTC addresses the same thing?


texts: Of the many, many crypto address out there, how many are really being used?

texts:
I am not asking how many Bitcoin addresses there are. I am asking how many ARE being USED.

I mean, Im sure there is alot of empty Bitcoin adresses out there, but, how many of are people just creating a account and just saying: "Hm, I think I will buy it in a month or so." and then go onto never buy it, or perhaps some who create it but have no intent of using it?

Im asking if there is a way to know a rough estimate of how many people are holding Bitcoin?


texts: Can you specify more than one output index in a transaction's input?

texts: It looks to me like each input to a bitcoin transaction has an index that specifies only one output from the input its spending. Is there a way to specify more than one output index, or do you have to create a second input line that contains the same input ID with a different index? It seems like that second way is wasteful of blockchain space - I would have thought there would be a way to simply specify multiple indexes. Is there a way to do that?


texts: How Does the SPV merkle path form of multiple transactions in Merkle block looks like?

texts:
While I'm studying about the Bitcoin, I've wondered how many merkle paths should be contained in merkle block.
From the point of view of Merkle path, it is generated as the form of containing hashes of counterpart stepping up from bottom to top.
For example, if I have 4 transactions(let me use tx1, tx2, tx3, and tx4) in a block, then the hashes of them(h1, h2, h3, and h4) will be located at the bottom as the leaves. The parents of them will be (h12 and h34), after all, the merkle roots will be (h1234). So, if a SPV node want to verify that the tx2 is in the block, the full node can offer h1, h34 as a merkle path (as well as block header), so that they can prove as the step of hashing will lead them to the merkle roots which is contained in block header.
However, If I requests to verify multiple transactions in a block (e.g. using Bloom filter), then what would be contained into the merkle block (which contains merkle path and block header)?
Does they have multiple merkle paths for each transactions which are interested in, so that the transactions can be verified respectively? or adapted merkle path to be included which encompass all transactions related? (e.g. if we want to verify tx1, tx3 then generating h2, h3; though this exmample seems not to be guaranteed to show the order of transactions)


texts: What is QuoteAssetVolume and BaseAssetVolume?

texts:
This is a JSON result for a candle returned by an exchange API for ETHBTC:

{ openTime: 1517340600000,
  open: '0.10635000',
  high: '0.10742000',
  low: '0.10635000',
  close: '0.10687200',
  volume: '600.53200000',
  closeTime: 1517340899999,
  quoteAssetVolume: '27.65975320',
  trades: 1233,
  baseAssetVolume: '259.09000000' }

What is quoteAssetVolume and baseAssetVolume?


texts: An online wallets that sends transaction change back to the original address

texts:
Is there any wallet client that conforms to the following:

The wallet client is accessed through a website (for portability).
The wallet client does not store any private keys (I know there is some trust involve). I want to access coins by providing a private key only, not by creating an account on the website.
Most importantly, all the transaction change is to be payed to the original address. I do not want any additional addresses created during a transaction. I want to keep it as idiot-proof as possible and not rely on myself to keep track of any additional addresses.

Thanks