texts: What if a country 100% denominated in a cryptocurrency loses internet connectivity to the rest of the world?

texts:
Please assume a small island nation becomes 100% denominated in a cryptocurrency.

Now please assume that for some reason the rest of the world manages to cut if off from the rest of the internet for some extended period of time, eg 1 year or more.

During the time that is isolated, it of course is able to continue using the cryptocurrency; however, what happens when connectivity to the outside world is restored?

Will all of this nation's transactions be lost forever and reset to the time before connectivity was lost?

If the transactions can be somehow recovered, what happens to all mining fees on the island during disconnection?

If anything is lost, how could a protocol be altered to manage this eventuality?


texts: Bits target, Increase/Decrease in ease of mine

texts:
I am currently studying Block Chain technology and at this moment studying the contents of blocks.

To my understanding; A block has to be mined every 10 Minutes.

If the Bit Target sees that Blocks are struggling to be mined every 10 minutes will it then decrease/increase the Bit Target?

If the Bit Target sees that Blocks are easily being mined in less than 10 minutes will it then decrease/increase the Bit Target

I know that the nonce is random I believe it starts at 0 and then is appended to the previous merkle root and then hashed and if its below the bit target then success and if its above then it increases the nonce +1 and repeats the process (Basically trial and error)

However the reason I found struggle is because I dont know if decreasing/increasing is making it more difficult/easier since I don't know the number ones its been hashed.

If somebody could answer my two questions and confirm the things I am saying are true/false really would appreciate it.


texts: I am wanting to buy a hardware for mining bitcoin and namecoin using Bitminter. But then Genesis Mining offer online cloud mining. I want to know if it's better to buy a hardware for mining bitcoin or use cloud mining?


texts: Is there a decentralized zk-SNARK (zero-knowledge Succinct Non-Interactive ARgument of Knowledge)?

texts:
Normally, in zk-SNARK, we need to generate two public keys: one for prover and one for verifier. However, the input parameter of this generator algorithm must be secret, meaning that it must be hidden for both prover and verifier.

And because of this, the process of those public generation is done by a trusted third party.

Since using a trusted third party is not desirable for decentralized blockchain, I am looking for a decentralized approach of those public key generation. Is there ? or it's impossible to have a decentralized zk-SNARK ?

P.S. More information about zk-SNARK is found here: https://media.consensys.net/introduction-to-zksnarks-with-examples-3283b554fc3b


texts:
I'm doing research on the above topic, but so far haven't found any or at the most only limitedly valuable articles/data published in recent time (past 6 months).

What I'm interested in is how users are protected against counter-party risks when using an exchange to trade BTC for fiat currency, and if there is any data available as to how often this protection has been necessary and did or didn't work.

In addition, I'm curious if there are any post-trade security issues (albeit I don't imagine there could be any, asides from the classics like losing your pw, wallet or credentials to the nether or a third party) and general post-trade procedures which alter from the usual bitcoin trade sans exchange service.

Are there numbers declaring these risks? Statistics that are freely accessible, which I might have missed? I've been looking for data the past hour but so far have come up short. Keep in mind, the data should be as fresh as possible.

Of course I do take all kinds of other statements as well - articles, news, reviews. But a neat statistic or similar would quite simply save me the hassle of constructing one myself.

Thanks for your help!


texts: How to integrate Blockchain Wallet API V2 to php

texts:
I have been using Bitcoin (JSON-RPC) for Blockchain.info

this plugin for bitcoin transaction in magento. one day suddenly it stopped working due to update in block chain wallet version. so i switched to spectrocoin. Later i found that spectrocoin is not working the way i have expected .So i decided to get a fix for appmerce.Then i found this Blockchain Wallet API V2

I went through it's documentation but i couldn't find a way to integrate this to magento. I can see lot of js files. So i'm open to suggestions.I would like to know how can i integrate  Blockchain Wallet API V2` to magento or PHP.


texts: Is Bitcoin a fully decentralized network, or how do clients connect to the network?

texts:
I read that Bitcoin is a fully decentralized network, but I don't understand how Bitcoin's client can connect to the network. I think that client must use some server for this action like other P2P networks: BitTorrent or P2P warez networks

Therefore, it's not a fully decentralized network. Did I get that right? How does a client connect to the network?


texts: MtGox websockets api returning "400 Bad Request"

texts:
I want to get started with the Mt. Gox websockets API, but I can't seem to get a good response from the server.

I'm sending the following (captured with Wireshark):

GET /mtgox HTTP/1.1
User-Agent: websocket-sharp/1.0
Upgrade: websocket
Connection: Upgrade
Host: websocket.mtgox.com
Sec-WebSocket-Key: LtH+YFgnW1N8KDLDbocsUQ==
Sec-WebSocket-Version: 13

and the server responds:

HTTP/1.1 400 Bad Request

I've tried sending the handshake via telnet and with this C# code and I still get a 400 Bad Request error:

class Program
{
    static void Main(string[] args)
    {
        ClientWebSocket ws = new ClientWebSocket();
        Task connectionTask = ws.ConnectAsync(new Uri("ws://websocket.mtgox.com/mtgox"), CancellationToken.None);
        Console.Write("Connecting");
        while (!connectionTask.IsCompleted)
        {
            Console.Write(".");
            Thread.Sleep(100);
        }
        Console.WriteLine(ws.State);
    }
}

(The last line printed is "Closed" and when I inspect the handshake with Wireshark I see the same 400 Bad Request)

Any ideas what I'm doing wrong? I can't see much documentation or samples using the websockets API so I don't really have anything to compare to :(

In response to sta's suggestion, I tried this (using WebsocketSharp):

static void Main(string[] args)
{
    WebSocket ws = new WebSocket("ws://websocket.mtgox.com/mtgox");
    ws.Origin = "http://websocket.mtgox.com";
    ws.Connect();
    ws.OnMessage += (sender, e) =>
    {
        if (!String.IsNullOrEmpty(e.Data))
        {
            Console.WriteLine("{0}", e.Data);
        }
    };
    Console.WriteLine("{0}", ws.IsAlive);
    Console.ReadLine();
}

This displays FALSE so there's still something I'm doing wrong :/ I haven't had a chance to dig into WebSocketSharp yet though

Update:
With WebsocketSharp setting the Origin header correctly, Wireshark shows the mtgox server accepting the websocket upgrade:

HTTP/1.1 101 Switching Protocols\r\n
Upgrade: websocket\r\n
Connection: Upgrade\r\n
Sec-WebSocket-Accept: 2+1ghzJ/Itt6w1aBdUteghcsJHk=\r\n
\r\n

But WebSocketSharp still reports the connection as closed :(


texts: How to use litecoin testnet on fully synced litecoin core on amazon ec2 instance

texts:
I run a synced litecoind on amazon ec2 linux instance.

[ec2-user@ip-xxx-xx-xx-xxx ~]$ litecoind -version
Litecoin Core Daemon version v0.13.2.1

[ec2-user@ip-xxx-xx-xx-xxx ~]$ litecoin-cli getblockcount
1411130

I tried starting daemon with below commands

litecoind -testnet -daemon
litecoind  -daemon , then litecoind -testnet

I want to get litecoin testnet address to test sending LTCT. But when I generate address i get litecoin address. How can I use this core to switch between main net and testnet ?

UPDATE

[ec2-user@ip-xxx-xx-xx-xxx ~]$ litecoind --testnet --daemon
Litecoin server starting
[ec2-user@ip-xxx-xx-xx-xxx ~]$ litecoin-cli getnewaddress
error: couldn't connect to server

  top command shows litecoind running.
   5787 ec2-user  20   0  786m  26m  288 S  1.0  2.6   0:00.63 litecoind

Is it okay if i kill the daemon ??

Please Help!


texts: How do I tweak the bip340_test_vectors to check that signature verification fails for other test vectors?

texts:
I now understand why some of the bip340_test_vectors fail signature verification.
I would like to tweak these test vectors to check that signature verification fails for other test vectors. How do I do this?


texts: Does Bitcoin's SHA256 proof make a 51% attack more likely?

texts:
Ethereum's description says that Bitcoin's mining algorithm requires only a simple SHA256 computation, which caused the creation of specialised ASICs, which centralizes mining in the hands of a few actors (ie. ASIC manufacturers), making 51% attacks much more likely.

Is that right?

SHA256 >>> ASIC >>> Centralized mining >>> 51% attack?


texts: Will I double my money after a bitcoin hard fork?

texts:
Could anyone please explain to me how this fork will work?

Examples would be greatly appreciated. The way I'm understanding is, if I have 1 BTC on Coinbase, they will match it. So after the fork I will have my 1 BTC and 1 B2X (Bitcoin 2x). Let's just say I sold my 1 BTC, will I still have my 1 B2X to sell? Does this mean free money?


texts: How to send everything in a bitcoind account?

texts: I have create an account in bitcoind, which has got some balance of 1.77 btc, I would like to send everything to another address that is an admin address, so is there any rpc method to send everything or need to do  transaction fee calculation for this.  If transaction fee calculation has to be done, please let me know the calcuation, this particualar func has to be impl in my backend for a platform.


texts:
I recently invested in digibyte.
As someone of IT-security field, I'd love to know how the passphrase is stored in digibytes wallet.dat.
The Bitcoin2John doesn't work on it and hashcat, too, has no support for the wallet.
I couldn't find any information on how storage is done, so I'm asking you.
Best wishes and thanks in advance


texts: Other than relying on "side-chains", is there any way that Bitcoin could solve "micro transactions"?

texts:
I am very aware of the Lightning Network, and have repeatedly tried to gain a full understanding of it and start using it. I find that, whether it's due to it being too complex or me being too stupid, I just can't seem to start using it. Even though I have a high motivation to figure this out, I just "zone out" and give up due to all the complexity and how obscure it feels.
Maybe it will be a big thing, but I have my serious doubts. It seems too complicated and confusing, like the 32X add-on to the Mega Drive/Genesis video game console. Few bought it. Its power should've been included in the main console, or in the game cartridges.
What would it take for Bitcoin itself (no add-ons) to start supporting some kind of "microtransactions" with much smaller (or no) fees and a near-instant settlement period? Perhaps there could be a maximum value for such transactions, or something, but as long as you keep under that number, you can send as little as one (1) satoshi to somebody else for free and no waiting?
At least in theory, that sounds reasonable to me. Since the transactions are so small, it doesn't matter as much as a huge/large transaction, sent via the classic Bitcoin transaction mechanism with the high fee and minimum six confirmations, etc.
But would it be possible technically?


texts: How to get new address on bitcoin core through extended public key

texts:
i am going to lunch a new service for merchants to use my service API to receive payments directly in their wallets through xpub key , now i have installed bitcoin core is this possible with bitcoin core or i need as well electrum server

<?php
    //replace with your BIP32 extended public key
    $xpub = "xpub661MyMwAqRbcGTFHLp4c7j2hByE3qAZdN37FqJHTAmSPE2vfL4GAQ4mZvGZz4bVzpfdwoeoEBXWV5g2vWwP";
    $url = "https://api.smartbit.com.au/v1/blockchain/address/".$xpub;
    $fgc = json_decode(file_get_contents($url), true);
    $next = $fgc["address"]["extkey_next_receiving_address"];
    ?>

    <!DOCTYPE html>

<?php echo $next;?>

    <?php

    Print_r($fgc);
    ?>


texts: Heartbleed: When will bitcoind 0.9.1 be released for Ubuntu 12.04?

texts:
I am running bitcoind 9.0 on a server (without GUI) with Ubuntu 12.04 (Precise Pangolin)

When I enter in my shell

bitcoind getinfo

I get

{
    "version" : 90000,
    "protocolversion" : 70002,
    "walletversion" : 10500,
    ...
    "errors" : "URGENT: Upgrade required: see https://www.bitcoin.org/heartbleed"
}

When I go to https://www.bitcoin.org/heartbleed I find a link to the download-page: https://bitcoin.org/en/download. On this page is a link for Ubuntu:

https://launchpad.net/~bitcoin/+archive/bitcoin

There I can read, that I must add this lines to /etc/apt/sources.list

deb http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu precise main
deb-src http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu precise main

I already had entered this lines some weeks before (to be able to install version 0.9)

But when I enter

bitcoind stop
apt-get update
apt-get upgrade
bitcoind
bitcoind getinfo

I get exactly the same message:

"version" : 90000,
...
"errors" : "URGENT: Upgrade required: see https://www.bitcoin.org/heartbleed"

What must I do to get a version of bitcoind that is not vulnerable to heartbleed?


texts: How to convert a WIF private key to a BIP32 extended private key

texts:
I am trying to recover the extended BIP32 master private key from its extended BIP32 public key (which I already know) and a WIF private key (which I obtained by decrypting a BIP38 seed with a passphrase).

I followed the steps described in this article from Vitalik Buterin, but to use the crack_bip32_privkey function in pybitcointools, I need to have a private key in BIP32 format (not WIF). I can see how to obtain a BIP32 private master key from a BIP32 seed (with bip32_master_key), but not how to do the same from a private key in WIF format.

How can I convert the WIF Private key into a BIP 32 private key (with Python, .NET or Javascript)?


texts: How to keep my bitcoin safe when I move my bcash?

texts:
I had some bitcoin during the coinsplit, so now I have bcash that I want to move.

When I send bcash there is a risk that someone copies the transactions and uses it to steal my bitcoin. Most people recommend moving the bitcoin to a new adress for this. this is not practical for me right now, will it work to just move my bcash to a new adress instead before I send them or will this also allow an attacker to copy the transactions?


texts: Are Bitcoin ASICs good for anything else other than mining?

texts: If I purchase an ASIC (hypothetically) and then for whatever reason Bitcoin disappears, becomes defunct or otherwise, is there anything else I could possibly use it for, such as SHA256 cracking - or is there no other possible use and does it become an elaborate doorstop?


texts: What are the top sites to purchase bitcoin from?

texts: As a newcomer to bitcoin, what would be the top websites for purchasing bitcoin?


texts:
I don't like asking coin base to create an account for me and having them give me my private key. How can I do all of this process myself?
Either bitcoin or ethereum


texts: Can I retrieve my Bitcoins when I only know my receiving address?

texts: I lost my wallet identifier and mnemonic. What I only have is my Bitcoin receiving address, 1EAd1Qua6fzyenPeSMRxYcpbcKgYUBpxQ7. I also lost the "Welcome to my wallet..." message in my e-mail. What do I do now? Please help, my bicoins are inside!


texts: Why didn't the creator didn't manage to allow people to be able to mine without needing a mining pool ?


texts: How do atomic swaps work when blockchains operate at different rates?

texts: If two cryptocurrencies work on blockchains that have very different confirmation / finality rates, or blocks are mined / minted / created at very different rates, how do atomic swaps match up? What if the prices change during the swap?


texts:
Bitcoiners seem to love to talk about anonymity. But to me, anonymous transactions are far from Bitcoin's greatest strength. And to some, the need for high anonymity is the first sign that someone is "up to no good".

But what happens if you need to the opposite? I find myself in a situation where I had listed a bitcoin donation address on my website, but someone was able to deface my website and put another adress in instead.

Now, of course this is a special situation, and since I don't know my adress by heart, it went on for a bit before I noticed this.

What got my mind buzzing was when I put my real adress back up, and a person asked me "How can I be sure this is really your wallet?"

The question is, how can I prove that I am on the other side of the bitcoin address on my public website? Sending screenshots is a bit impractical, and honestly doesn't really tell me much. Is there a way to do some kind of handshake with the recipient or in any way verify the identity of a bitcoin address?

I know this is directly against the core principles of anonymity, but a currency will still need trust for commerce to flourish, and I am curious if there is any method one could use.

Right now, I'm juggling the idea that the user sends a microtransaction with a 6 digit code, and the recipient tells the sender the code when it appears in my wallet. This is inspired by mobile bluetooth trust syncs. But there must be an easier way. I imagine a very high level of ingenuity among the Bitcoin community, any ideas what could solve this?

If your idea is based on "theoretical software" (something that could be made, but simply hasn't) I'm willing to hear you out as well.


texts:
I’ve been attempting to set up my own wallet, but am having difficulties.  Last week I began installing the standard Bitcoin client.
When I first attempted I got to the process of downloading the blockchain.  My computer ran for about 36 hours until the process failed.  I asked on the message boards and they said there may have been some corrupted data.  I attempted to re download the blockchain, but when I reinstall Bitcoin, I now get a failed to initialize message.  I deleted the original files (except the wallet file) and still get a failed message when Bitcoin starts.  It's getting pretty frustrating.  I sent 1 bitcoin to the first address I created (though it had not yet and never did finish downloading the block chain).  Would deleting the wallet allow me to start over?


texts: Meaning of "fungibility" in "Zerocash (Zcash)"?

texts:
According to the following article, Zcash provide a high level of "fungibility". compared to other crypto-currencies.

Article link: https://www.investopedia.com/terms/z/zcash.asp

fungibility definition in Oxford dictionary:

(of goods contracted for without an individual specimen being specified) replaceable by another identical item; mutually interchangeable.

So, according to this definition, fungibility is NOT related to "privacy" (this is main concept Zcash provides). So, why other crypto-currencies such as Bitcoin and Ethereum does NOT have the same level of fungibility of Zcash?


texts: Is it possible to add funds to an already-open lightning network channel?

texts:
I would think that user A on a channel should be able to add bitcoins to a channel using the following steps:

Create a transaction sending more money into the main multi-sig account
Create a refund transaction for the amount in that transaction, using that specific transaction's output as the input to the refund transaction
Send the refund transaction to the channel partner for signature
Post the transaction created in (1) to the blockchain

Are there problems with this method? Is it possible to "top up" a LN channel in this (or any) way, using only one additional on-chain transaction (rather than the two you'd need to close and reopen the channel)?


texts:
I'm staying in Germany and I have a friend in India. He has a few ether coins in his wallet in India which he bought mid of 2017. He now wants to sell them.  But in India, because of taxes, he will not gain much profit.
So he asked me if he could send them to my wallet in Germany as a gift. I can sell them in Germany and send him the amount in parts as and when we happen to meet.
Since it is a gift and I have not bought the coins I will not have to pay any tax on it in Germany. Is this legal and what are the risks?


texts: Where do I include my wallet address after finding the hash less than target - bitcoin

texts:
Please help me understand the logic behind mining a bitcoin from scratch. I want to create a bitcoin miner, it will not receive any blocks from any pools. All should be done inside the miner.

So, I have made some progress, I've coded with vb.net and successfully got a result of a hash (old example)

Version 2
Prev. Block 00000000000000000A2940884E0C3BC96510CAD11912A527E9D15DF42F0E1D67
Merkle Root 2E99F445C007A9158207CC30CEBAD2B3D26C45FDAB2EBDF50D261335FC00D92C
Time    12/16/14 18:05:40
Bits    404454260
Nonce   3225483075

Block Hash  000000000000000015A8D88216918C8DE090268A5E7F53FEEF72CD111F7F27FF

So, suppose old example is a real one, so, I want to know where do I include my bitcoin wallet address if I want to get the block reward to my wallet address? Should I have hashed the wallet address with the above and hash with the wallet and come up with a hash which is less than the target? Or after getting a good hash, just send data to blockchain with the wallet address to receive the block reward? or should I create some other hash with my wallet address? what should I do to include my wallet address in this?

pseudo code would also be nice If you can provide for me to understand how to include my wallet address.

my pseudo code upto now

**Step 1**
version -> convert to hex

Prev. Block -> convert to hex

Merkle Root -> convert to hex

Time  -> get unix time and convert to hex

Bits -> convert to hex

Nonce -> convert to hex

**step 2**
Add hex values of all the above and then hash it with Double SHA256 to receive the hash value.

**step3**
Check if the final hash value is less than the target

**step 4?** what should I do with the above hash? where should I include my wallet address?


texts: How can I execute a 3-way escrow with 1 unknown party?

texts:
Good Evening-

I'm trying to execute an unusual 3-way transaction, where in one of the parties is not known at the start.

PartyA would initiate the transaction, and provide funding.
My thought was that he would transfer 1BTC to a dedicated wallet.

He'd then also start the transaction, and name Party B as one required signature.

For the third signature, he'd approach 5 random strangers.
He'd give them any and all information necessary to complete the transaction (including the private key of the wallet he just made if nec).

The first one who could propose a deal, and convince PartyB to accept it, would receive their share of the money.

For instance, c1 might offer B to split 80/20, where-as c2 offers to split 50/50.
PartyB signs the proposed offer from c2, and it can then execute.

It looks like there might be a way to do this with multiple signatures and p2sh, but I'm not quite sure how to make it work yet. Any thoughts or comments welcomed.


texts: How can I generate a QR code for multiple outputs?

texts: I have an online store where users can pay with Bitcoin. I'd like them to send the total amount they have to pay to an QR code. From there on, the sent coins should be redistributed to two different wallet addresses in a 90%:10% ratio. How can I possibly do this?


texts: Recovering bitcoins after the owner's death

texts:
My Brother died in April and we believe he had a bitcoin account. Is it possible to find out how to recover/take over his accounts?
I know this is a new form of currency but it seems odd there is no way of recovering information in these circumstances.
Any help would be welcome. I still have all his computers, so can anything be traced through them?
Thank you.


texts: Blockchain and anonymous data inside the chain

texts:
A Blockchain is often said to be a log of all transactions that were ever verified on a network.

I understand that therefore a purpose could be to make sure that the records are not altered. If they would, the chain would fail by its construction.

However, what do you do when you have sensitive data that you want to store in these transactions? The reason I am asking is because the Blockchain being a Distributed Ledger, everyone has access to view all the transactions/chain.

Use case example: bank transactions

A bank could launch a Blockchain to make sure that the transactions of their clients are irreversible recorded. However, these transactions might contain sensitive information (like the details of their client). When a new block is created, the entire Blockchain is validated, meaning that the person who is creating the transaction has access to the whole chain and thus the details of the client in the previous transactions.

What is then the use case and how do people look at it this type of problem from their perspective?


texts: Why is it important for checkpoints to contain well-formed blocks?

texts:
In the source code of the standard client, checkpoints.cpp has this comment:

//
// What makes a good checkpoint block?
// + Is surrounded by blocks with reasonable timestamps
//   (no blocks before with a timestamp after, none after with
//    timestamp before)
// + Contains no strange transactions
//

Why should it matter? Presumably the client would have accepted it anyway if they were downloading it normally, and if you were to specify a later block, that would still force the client to download the strange block. I don't understand the point of this restriction.


texts: What is the maximum throughput of the Bitcoin network? (2013)

texts: I have heard that the maximum block size means that the Bitcoin network has a maximum throughput. What is this maximum?


texts: How do I ensure that the multisig transaction that's signed by multiple parties is the same?

texts:
In multisig 2-3 escrow, what is best approach from below ?

1- Say I want to sign a rawtransaction from a customer and send it to escrow to sign so that 2 of 3 sigs are there to release fund.
But how do I ensure that rawtransaction is the same one that I created and not modified or created from customer ?

createrawtransaction '[{"txid":"564876",
"vout":0,"scriptPubKey":"8645231554",
"redeemScript":"2315454"}]'
'{"d5adf5sdf5s45":0.00015000}'

0df0sd0fsdfsdfs11dfs

signrawtransaction
'0df0sd0fsdfsdfs11dfs'
'[{"txid":"txid":"564876",
"vout":0,"scriptPubKey":"8645231554",
"redeemScript":"2315454"}]'
'["erwerw8e888"]'

{
"hex" : "0e0rw1e1rw1er1we1rw",
"complete" : false
}

It's possible the customer created his own rawtransaction and signed it and sent it to me, how do I ensure it is the same raw transaction that I created ?

2-Send sign rawtransaction to customer to sign 2-3 to release fund?
But how can I know if a customer made his own sendrawtransaction? Does there exist any bitcoin api rpc to test if customer already released funds?


texts: How websites like silkroad and pandora process transactions?

texts:
I've been reading about Bitcoin on the news and I decided to learn how it works. I'm sorry if I'm posting dumb questions.

How these websites process transactions? How can they monitor one or more receiving addresses per registered users? Do they use custom software that interacts directly with the blockchain?


texts:
Explain like I'm 5 years old and my other half of the brain is surgically removed :) I don't want to put a lot of stress on my brain

1.What are these bitcoin nodes and what purpose they serve?

2.and also why they are still running?

3.and does miners use them to mine or validate transaction anymore?

4.how bitcoind is related to any of them?

0-Bitcoin Core

1-Bitcoin Unlimited nodes

2-Bitcore nodes

3-Bitcoin UASF nodes

4-btc1 nodes

5-Bitcoin Knots nodes

6-bcoin nodes

7-Bitcoin Classic nodes

8-btcd nodes

9-Bitcoin XT nodes

10-TRB nodes

11-libbitcoin nodes

12-Bitcoin ABC


texts:
I'm trying to understand verifying Bitcoin transaction but I can't find this part anywhere. Summary, the process before forming blocks. My questions is:

1) When I send transaction, who validates it ? Here I think, who can check and found that I haven't got enough money in my wallet. Example; I send 100 BTC but I have only 50.
The problem is bigger because in my prior transactions, refund come back on "new" wallet and who can trace all my wallet to sum how much I have in that situation. I don't speak here on double spending. I understand that part.

2) Can one transaction go by mistake in two blocks, and who prevents this ?


texts: How does ENS prevent frontrunning attacks?

texts: Namecoin uses commitments to hide the domain. ENS uses simple hash, which is not hiding.


texts: I seem to have too many unspent outputs for my given balance. What am I missing?

texts:
I have an address on the testnet. I started out with 1.3 btc. I then sent 0.5 btc to another address. My balance is now 0.8. OK, that makes sense.

I expect now to have one UTXO which was the 0.8 in change from the previous transaction. But when I run listunspent, I see I have two UTXOs. The balance is correct, but it seems I have two outputs.

[
  {
    "txid":
   "321dab633022a33c3a49b4aab4b13d3c431771ae9402746dbb6dcc21be5fd603",
    "vout": 1,
    "address": "2N4wJG7gs1mVXeMkX2MCuyekZUCSzrW7CjT",
    "redeemScript": "0014221f8d76c5b85e979055e54ac97a0cada38bc4e9",
    "scriptPubKey": "a914803d96c7e19e4a568764f9912fa54499f814cd8e87",
    "amount": 0.79999834,
    "confirmations": 119,
    "spendable": true,
    "solvable": true,
    "safe": true
  }
]

When I run gettxout with the txid and vout 0, the first transaction UTXO is 0.5.

{
  "bestblock":
  "0000000000000043a1abc3cf9c778d3adeb417488019a507da871db9df74ffad",
  "confirmations": 119,
  "value": 0.50000000,
  "scriptPubKey": {
     "asm": "OP_HASH160 a43f8a90f292b6be0b487556ac357709a5e86480 OP_EQUAL",
     "hex": "a914a43f8a90f292b6be0b487556ac357709a5e8648087",
     "reqSigs": 1,
     "type": "scripthash",
     "addresses": [
       "2N8Dgvfmgs4fNCi7QatLZJR8ArvhPpMPW8P"
     ]
  },
  "coinbase": false
}

And when I run gettxout with vout 1, the second transaction UTXO is 0.799 (0.8) which is the balance.

{
  "bestblock":
  "0000000000000043a1abc3cf9c778d3adeb417488019a507da871db9df74ffad",
  "confirmations": 119,
  "value": 0.79999834,
  "scriptPubKey": {
    "asm": "OP_HASH160 803d96c7e19e4a568764f9912fa54499f814cd8e OP_EQUAL",
    "hex": "a914803d96c7e19e4a568764f9912fa54499f814cd8e87",
    "reqSigs": 1,
    "type": "scripthash",
    "addresses": [
      "2N4wJG7gs1mVXeMkX2MCuyekZUCSzrW7CjT"
  ]
},
"coinbase": false

}

And according to this: How to check if an output has been spent?

If gettxout returns something, then the output is unspent.

Why do I have two unspent outputs with the first one in the same amount that I sent to another address?


texts: Is there a JSON-RPC method for retrieving all transactions for a given address?

texts: I mean something like listtransactions method but with parameter .


texts: how to know if a webpage has mining code?

texts:
Until recently I have heard that lot of webpages are infected with the javascript which uses your computer's power to mine bitcoins.

Whats the correct method to identify if the website i am browsing is infected by this?


texts: What are the pros and cons of different methods for transferring Bitcoins between different wallet services?

texts:
I am interested in transferring Bitcoins between several different wallets: my Mt.Gox account, my Bitcoin client wallet, and my Blockchain wallet.  I am aware of two primary ways to transfer funds between any two of these:

Perform a transaction from one address linked to one wallet to an address associated with the other wallet service, or
Export private keys from one wallet and import them on the wallet I wish to effectively transfer to.

I was wondering what pros and cons there are to these two different methods and if there is an obvious "right way" to do it?  Any other methods, ideas or advice relating to transferring Bitcoins between these wallet services would also be appreciated.  My primary concern is maintaining security, however ease of use would I think obviously be a nice benefit.


texts: if I set a transaction fee from multibit for example, is it a fee I'm paying or is it a fee that the other party is paying; and to whom does that fee go to?


texts: Is there a step by step tutorial on does Ardor's transaction vouchers work?

texts:
When creating a transaction voucher on Ardor. Say alice wants to pay bob.

Alice logs into her own account and and puts in Bob's address and 9 ignis to send.

Alice also puts in her secret pass phrase and checks off the voucher checkbox.

Now click submit and you're given a QR code and json data.

So does bob just broadcast this transaction when I give him this voucher?


texts: Transaction doesn't show up in my Blockchain wallet

texts: I am a beginner at Bitcoin. I sent my 0.0161034 BTC from LocalBitcoins to my Blockchain account. It said that it would take up to 30 minutes, but after 16 hours I still didn't get any money in my Blockchain wallet or anything to show up in the transaction history there. I also tracked my transaction on an explorer, where it's confirmed by 72 but it still doesn't show on my Blockchain wallet.


texts: How to sign Raw Transaction with Multiple Inputs


texts: How does tx fee calculation work when txin and txout are similar amounts?

texts:
This website has an example called "When Too Much is Not Enough" on its main page. I'll quote it an case this is changed in the future:

  Suppose you have only two outputs in your wallet, worth 1 XBT and 2
  XBT. You want to buy something for 2.999 XBT. The coin selection code
  has no choice; it has to select both coins to get a big enough total
  to make the transaction. That means the change will be 0.001 XBT,
  which triggers the 0.0001 XBT fee for having an output that's less
  than 0.01 XBT. As a result your transaction will fail, because the
  amount you're sending plus the fee is more than you have.

  What this means is that there's no way of spending 2.999 XBT when you
  have 3 XBT. You could send the full 3 XBT to the vendor without a fee
  (assuming the outputs are sufficiently old to satisfy step 3), but
  some vendors ask you to send the exact amount they specify.

Since the 1 BTC input and the 2 BTC input are interchangeable in this respect, let's (for the sake of simplicity) settle that the bitcoin client decides to send the 2 BTC input in full for this example.

Then it has to split the 1 BTC input into a 0.999 BTC output and a 0.001 BTC output. I assume that doing so requires a fee because one of the outputs is smaller than 0.01 BTC. So 0.0001 BTC have to be paid for this. This means that there now is a 0.999 BTC junk and a 0.0009 BTC. The 2 BTC junk and the 0.999 BTC junk are send away and the 0.0009 BTC junk remains at its owner.

Can you tell me what I did wrong to get an outcome different from the one of the authors of that website?


texts: Please help with my unconfirmed transaction (for two days already)

texts:
Could someone pleas help me with this trancaction,highly appreciated :).

Link underneath


texts: Transaction unconfirmed after a day! Help!

texts:
I made a bitcoin transaction yesterday and it's still unconfirmed. Maybe the default fee of my wallet was too low. Could anyone please help me get this confirmed? It really is urgent. I'd greatly appreciate it!

Here it is:
https://blockchain.info/tx/1e6ba30a70a6ed95a0095bd672f75e101724751e4a0c22769c0a89813473bebf?show_adv=true


texts: Where can I go to read up on encryption methods used in Bitcoin? I am particularly interested in the idea that I can use a private key to sign something and it proves to the world I have the private key but yet does not reveal the actual key.  This is a topic of mystery to me, how this is done.


texts: What prevents DoS based on near-valid block timestamps?

texts:
Upon receiving a newly mined block, the block timestamp validation is performed here:

https://github.com/bitcoin/bitcoin/blob/master/src/validation.cpp#L3263-L3270

Q1: As for the second check (block timestamp too far in the future), what prevents a miner broadcasting a block that's near the limit in the future and having some of the nodes accept the block, while some other nodes reject the block?

Q2: If a part of the network accepts a block and the other part of the network rejects a block (i.e., not record the block it in its blocktree due to invalid time stamp), can the network recover from this in any way?


texts: Are there two versions of the armory webpage?

texts: I'm seeing https://btcarmory.com/ and http://bitcoinarmory.com are both sites. Are they both legit? what is the reason for the duplicate? They seem to be slightly different.


texts: How do nodes reach consensus on when the target is recalculated?

texts: Due to network latencies, some nodes may think they are at a different block height than the rest of the network. How then does a node decide if the target has been recalculated since that changes every 2016 blocks.


texts: Can too big hosted mining service be mitigated by allowing customers to choose mining pool?

texts:
Let's say a company is hosting mining hardware, either hosting customers' hardware or renting out the hashes produced by hardware owned by the company, or both. So the company is physically controlling the hardware.

What if this hashpower reaches a percentage of global hashpower that makes double-spends possible.

Can this be mitigated by the company allowing customers to select which mining pool they want their hardware/hashpower pointed at? For example through the company's web interface.


texts: What does blockchain.info wallet need your email for?

texts:
This question is related to the specific software product, but comments on the need for usage of an e-mail address in similar software products are welcomed.

I installed blockchain.info wallet to my mobile device and it is all good, but it says in settings that I have unconfirmed e-mail. OK, I confirmed my e-mail, but now I'd like to know what it will be used for.

I can see 3 options:

Notifications
MFA
Password restoring

AFAIU, it is used for login to the web interface and notifications. Would like to be sure if I am right about this.


texts: How to correctly implement the FEE increase using bitcoind?

texts:
I have read that once a Bitcoin transaction is created, it never automatically expires. In theory, a transaction could be created, get stuck at 0 confirmations for some years, and then all of a sudden confirm.

The proper way of increasing the fee would be to send another transaction that uses exactly the same coins as the first transaction.

How can I program the correct way via bitcoind?
Which commands should I use?


texts: Is there a way to use My Wallet account with bitcoin-qt client?

texts: I have some funds on My Wallet account (Blockchain.info) and I'd like to have a possibility to use them with my bitcoin-qt client. Is there a possibility to do that? Please give short description. I get many "Yes" answears on some forum but still can not do that.


texts: Fees for bitcoind sendmany, limits for number of end addresses

texts:
I have two questions, both about sendmany.

First, is there any limit on how much transactions can I send with sendmany? (Apart from bash's limit with maximal parameter length.) Is sending about 500 transactions OK?

Second, what will be the fees used when I send a lot of transactions (and thus, probably creating a big transaction)?


texts: Share a common wallet.dat file between two servers

texts:
Note this is not duplicate of Is there a way to change the wallet.dat location without changing the entire data directory?

I want to change wallet.dat file location. From the above link it seems to be impossible. But is there any way i can update wallet file location in bitcoin source code https://github.com/bitcoin/bitcoin and run make command to make it executable. Here is the reason why i want to do this:
https://serverfault.com/questions/888293/share-a-file-between-aws-servers

I want to share a common wallet.dat file between two server.


texts: Bitcoins are encrypted with SHA-256, and Ethereum is encrypted with SHA3.  Why can miners for SHA-256 encryption guess hashes in the TH/s when miners for the SHA3 encryption can only hash in the MH/s?  Is the algorithm more complex?


texts: Creating my own script for proof of reserves

texts: I recently came across the topic where exchanges have to constantly give a proof of solvency to prove that they hold enough bitcoin for it's clients. I was however intrigued by the way an exchange would give a proof of reserves. I was trying to build a script for generating the proof of reserves using the Invalid input scheme to prove the reserves of bitcoin a node holds. Are there any resources which I can refer to for the same?I have been struggling to find any. Any help would be very much appreciated.


texts: Can cryptocurrencies never be fully decentralized because finding peers is centralized?

texts:
When initially running a cryptocurrency client, it needs to fetch peers from a centralized source. If an attacker gains control of all of a client's default peers servers, they would be able to restrict the client's access to the rest of the peers. Then, they can give the client fake data and there would be no way for the client to tell.

Are we just ignoring this issue because it'll be hard to gain control of the servers?


texts: TransactionId Not working Second Time in NBitcoin and QBitNinja?

texts:
I am trying to send bitcon from my address to another address. i had 0.0024BTC in my wallet and then i performed a transfer using this article:
https://programmingblockchain.gitbook.io/programmingblockchain/bitcoin_transfer/spend_your_coin#sign-your-transaction
The Transfer was success. I was happy. Now i again tried to perform another transaction. Since i still have unspent amount in that transactionId so i used the same TransactionId this time as well. I got success response along with hash in the code but when i went to explorer i cannot find another transaction there is only one transaction. Should i use different transactionId or is this anything i missed. Please help !
Thanks in advance


texts: How create / generate a coinbase transaction for a new block?

texts: I am coding a miner program with C, and right now I need some info of how create / generate a coinbase transaction to add to the block before submit it to the bitcoin network. Someone can indicate any article / tutorial explaining this (i am searching for this for a while now, and finding nothing useful of this sorts).


texts: USDT transfer at BTC address from binance exchange

texts:
I am transfer USDT to BTC address by mistake but since last 3 month USDT missing .how I will take back in my account.
  Binance not help me for get back my USDT.or BTC. They r saying when your transection abnormal or cancel you contact us.since last 3 month I am reading these by binance.


texts: Why miners try to produce big blocks i.e. try to put transaction in a block as many as possible?

texts: Why miners try to produce big blocks? What if, does a miner deliberately produce a block with a single transaction (and a coinbase transaction of course) without considering the whole unconfirmed transactions, in order to gain the reduce of network latency advantage or for some other purpose?


texts: Can we use lnurl-auth to create a better password manager?

texts:
LNURL-auth can be used to implement registration/login in a web app in which users don't need username/password or other credentials instead they can just use their LN wallet to login. However cannot be used if the website doesn't support it so can we do this locally for websites using a browser add-on?
Right now only few websites support it including LNMarkets
I have also created an issue in btcpayserver repository to support it: https://github.com/btcpayserver/btcpayserver/issues/2004
How would LNURL-auth work with a password manager?
When you create a new password, the password manager uses the main lnurl-auth key to derive a key specific for that password(challenge: random value), uses that key to sign the challenge and then saves both the public key specific for that password plus the signed challenge locally.

When the user needs to login using one of the saved passwords in a website, scans a QR code shared by password manager browser add-on or enters some PIN used by internal LN wallet in pwd manager, it retrieves the public key, checks it against the challenge signature and attempts login for that user.
What are the pros and cons if this is possible?
I don't understand the below part mentioned in this link: https://xn--57h.bigsun.xyz/lnurl-auth.html

In fact, lnurl-auth is very unique in the sense that it doesn't even need a Lightning wallet to work, it is a standalone authentication protocol that can work anywhere.

Also I don't know why linking LN wallet on https://lnmarkets.com requires user to pay 100 sats invoice. Is it added to avoid spam registrations?

I was not asked to pay anything to login on https://etleneum.com


texts: How do I see the IP address of a bitcoin transaction?

texts: How do I see the IP address that someone used to send or receive bitcoins with? Is it stored in the blockchain?


texts: How do I get my bitcoins back if they got sent to an incorrect address?

texts:
I loaded my localbitcoin wallet with a total of $100 - I did 2 separate transactions. The first time I added $50, I tried to send half of it to cardrockcafe but it never showed up, so I tried to add the remaining amount. That also never showed up. A few days later I added another $50 to my localbitcoin wallet and attempted to transfer it to a different website. Again it never showed up. I've set up tickets with all 3 websites and not really getting any responses that are helpful so I've been researching on my own what is going on.

I noticed that when I copied the address and pasted it onto another website the address changed to a completely different one. So I went back to my last few transactions where my money never showed up and the addresses are different as well; meaning the one I was supposed to copy and paste was different when I actually pasted it.

So I added money to a different wallet and I actually typed out the address when I tried to transfer my money to website C instead of copy and pasting them, and the money or bitcoins rather showed up rather quickly. I checked the receiving address of one of the last transactions where my money disappeared and the address is stating the money is still there, but I cannot get to it, or do not know how to retrieve it, can somebody help?


texts: How to build a portable bitcoind binary for macOS?

texts:
Bitcoin Core ships a portable bitcoind with the Linux and Windows releases, but doesn't ship one with macOS. And I couldn't find instructions on how to build one.

Can someone provide step-by-step instructions on how to build a portable bitcoind binary for macOS?

The host platform can be Ubuntu or macOS. I have access to both.

(Just to clarify, the goal is to have a self-contained bitcoind binary that runs on different macOS machines without having to install additional dependencies)


texts: CHECKMULTISIGVERIFY with public key hashes?

texts:
Is it possible to create a script that implements m of n pay to public key hash neatly? One way to do it would be to make use of OP_IF. But, that's not neat.

CHECKMULTISIGVERIFY can implement m of n, however, it takes public keys instead of public key hashes.

Thanks


texts: What Bitcoin profitability calculators account for taxation on miner income?

texts:
If I were to run a miner, I want to be ethical and pay all relevant income tax and gain all required licensing, etc for my country.

My miner income is probably taxed at a 1099 income rate or lower, but to be less region-specific, a calculator could potentially account for hardware (and other) costs and also allow the user to specify tax rates.

What profitability calculators take this into account?


texts:
After running 'autogen.sh', './configure' and then 'make', I keep getting the following error:
Undefined symbols for architecture x86_64:   "__ZN5boost10filesystem4path5imbueERKSt6locale", referenced from:       __Z16SetupEnvironmentv in libbitcoin_util.a(libbitcoin_util_a-system.o) ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status make[2]: *** [bitcoind] Error 1 make[1]: *** [check-recursive] Error 1 make: *** [check-recursive] Error 1
I was told that boost is clang compiled and thus, GCC incompatible, so I've been trying to recompile boost with GCC via:

HOMEBREW_CC=gcc-10 HOMEBREW_CXX=g++-10 brew install --build-from-source boost --HEAD
`brew install boost --build-from-source --HEAD'

Both of these commands throw the following patching error though:
==> Patching ==> Applying 7b3fc734242eea9af734d6cd8ccb3d8f6b64c5b2.patch patching file boost-install.jam Hunk #1 FAILED at 483. 1 out of 1 hunk FAILED -- saving rejects to file boost-install.jam.rej
Any idea how to fix this problem and successfully recompile boost? Please let me know!
EDIT: For clarification, I'm trying to build Bitcoin Core v0.21.0 on macOS Catalina version 10.15.7
UPDATE:
Finally got this working - turned out I had an outdated version of gcc installed via MacPorts, in addition to Apple's default compiler, which seemed to have been interfering with things. Once I uninstalled MacPorts, everything started working smoothly if I configured with --with-gui=no


texts:
Most web apps that accept bitcoin (whether it's an exchange, a gambling site, etc) provide the user with a public address for depositing bitcoins into their account.

How are these web applications storing the private key associated with the deposit address? What is the best practise for the storage of the private keys from a security standpoint? What is the best storage procedure for web developers looking to create large quantities of key pairs for their web applications?


texts: Could not detect boost libraries when configuring Bitcoin core - Apple M1 Mac Mini

texts:
I´m trying to install Bitcoin from source on an Apple M1 Mac Mini (Big Sur 11.2.3) and Im getting this when running
./configure --prefix=$PWD/depends/arm-apple-darwin20.3.0

"We could not detect the boost libraries (version 1.58.0 or higher). If you have a staged boost library (still not installed) please specify $BOOST_ROOT in your environment and do not give a PATH to --with-boost option."
config.log tells me:
configure:32586: checking for boostlib >= 1.58.0 (105800)
configure:32618: g++ -std=c++17 -c -g -O2 -I/opt/homebrew/opt/libffi/include -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS -DMAC_OSX -DOBJC_OLD_DISPATCH_PROTOTYPES=0 -DPROVIDE_FUZZ_MAIN_FUNCTION  conftest.cpp >&5
conftest.cpp:73:10: fatal error: 'boost/version.hpp' file not found
#include <boost/version.hpp>
         ^~~~~~~~~~~~~~~~~~~
1 error generated.
configure:32618: $? = 1

I have boost installed via homebrew in /opt/homebrew/Cellar/boost
(Version 1.75.0) and I did try
export BOOST_ROOT=/opt/homebrew/Cellar/boost

before building, but keep getting the same result.
echo 'export PATH="/opt/homebrew/opt/icu4c/bin:$PATH"' >> ~/.zshrc
echo 'export PATH="/opt/homebrew/opt/icu4c/sbin:$PATH"' >> ~/.zshrc
export LDFLAGS="-L/opt/homebrew/opt/icu4c/lib"
export CPPFLAGS="-I/opt/homebrew/opt/icu4c/include"

also didnt help. Any ideas very much appreciated. Thanks


texts: How to access any transaction detail in Bitcoin version 0.8 and above?

texts: Since the Standard Client version 0.8 removed the full index of all historical transactions, some Bitcoin applications that relied on that functionality have stopped working. For example, one is no longer able to find out the sender of a given transaction by pure RPC calls. How can one access that transaction detail in the newer versions of the Bitcoin client?


texts: Fork rate range in terms of network security

texts:
I am really new to bitcoin and am trying to understand the basics. Fork rate/Orphan rate is a measure of network security.

The higher the fork rate, the more compromised the system. Also fork rate is directly proportional to block size and inversely proportional to block interval time.

My question is what range is considered safe for fork rate in terms of network security?


texts: Is there a fixed order for all transactions in the block chain?

texts:
Every block in the block chain contains a list of transactions. This list has a certain order which is basically set by the miner introducing the block. The merkle root in the block header requires that this order is fixed.

Therefore there is a fixed order for all transactions in the blockchain which cannot be modified at a later time (except for the usual temporary forking).

Is that correct?


texts: Why isn’t connecting to your own local node a common feature for Bitcoin clients?

texts:
I come from the Monero community and connecting to my own local node running on my home PC is very simple whether it’s on the GUI, CLI or a mobile wallet.

Why does Bitcoin not have the ability to do this easily? Current using the electrum live server as a workaround but can’t help but feel this could be easier.


texts: Does number of inputs or outputs affect bitcoin transaction fee?

texts:
I would like to know how inputs and outputs affects my bitcoin transaction fee using legacy address, and how using a segwit address will decrease the same  transaction?

and how they will be calculated?
if input and outputs affects how can avoid that, apart of segwit address method?

thanks a lot.


texts: I sent a payment of 0.9995 bitcoins back in April to my MtGox account. However I just checked and it has 0 confirmations. Additionally it doesn't show in my wallet or my MtGox account. Is it lost? Can I get it back?


texts:
Good day.

I have a slight issue! A friend of mine has imported a few wallets to his main wallet. All the imported wallets has "Non Spendable Bitcoin" in them ranging from $2-$45k respectively. Is there any way i can retrieve them via finding the private keys for them to make the btc coins spendable again? Any help or advice will be highly appreciated.


texts: How can a deterministic wallet have one private key but multiple public keys

texts:
If we take for example bread wallet.

There is one mnemonic to remember, which means one private key?

But when you use the app, your public address constantly changes.

So more than one public key?

How is this possible?


texts: Understanding Storing Bitcoin and wallets

texts:
I bought some bitcoin and have them saved on my PC on a MultiBit wallet.

I am a little confused as to how they are actually stored.

Are the bitcoins tied to my machine? So if I lose my PC the bitcoins are gone forever.

Or if I download the same multibit wallet on another computer can I enter my password and access my bitcoins from that machine?

Also what is a paper wallet?

And final question..... I have read Multibits policy on restoring wallet and the use of wallet words.  Are wallet words used by all types of wallets or is that just a Multibit specific security measure.

All simplified and intuitive answers will be of benefit as more people are starting to become aware of bitcoin and are probably thinking and asking the same things.

Thanks in advance


texts: Could a Proof of Burn function be implemented into Bitcoin Core to help prove loss of private keys?

texts:
Is there a list of self reported BTC addresses with lost private keys? Of course such a list would never be conclusive as we would have to trust the people who report that the keys were lost.

Could this trust issue be eliminated going forward by creating a Bitcoin proof of burn function (forcing BTC to be sent to a random address where it is extremely unlikely nobody holds the private key).

Such a function could not include the ability for the user to send BTC to an address of their choosing. It would need to be separate from the private key system already in place. It can also not be retroactive.

Assuming that the Private Key and "Proof of Burn Key" are stored separately, the purpose of this idea would be to allow:

Those who have lost their private key to prove their loss of ability to find it (this could have an impact on insurance, tax, inheritance claims or more)
You could use a multi-sig Proof of Burn system to help minority claimants (of blockchain businesses, heirs to a bitcoin estate, etc) the ability to call the bluff of a rogue partner or other beneficiary from making a "lost key" claim.


texts:
In this transaction;
https://blockchain.info/tx/573700fe19dbc926d037ee67dbe882ebcf3f765f1a3fcc9577665ba40554485f

All of addresses are segwit. According to my research this transaction size must be 166 bytes. But is seems 248 bytes.

Is there any idea?


texts:
I am trying to generate my own address using my GPU with oclvanitygen, but it seems like that it only displays the:

CPU hash
GPU hash, and
Found delta

but not a private key?

Any idea why? Vanitygen using CPU is displaying private key but not oclvanitygen.
I am using Windows 7 Ultimate 64 bit and Sapphire 7970


texts: What prevents a malicious user creating a new transaction using signatures of an old mined transaction if the inputs have the exact same balance?

texts:
I am NOT talking about double spending. I am talking about this type of scenario:

Let's say address A has 1 BTC balance initially. A valid transaction is created and for simplicity's sake, assume all the balance is transferred to address B in a valid manner.

Okay, now that transaction has been confirmed and A has also received another 1 BTC from some other random address.

Now, what prevents a malicious user, to rebroadcast the old transaction as the same conditions are being met. The input has the exact same balance, the old signature is telling to send the balance to B etc.

Obviously, this would mean it would be the same transaction ID and the network would reject it. So my question is, what is the variable in a transaction that allows you to prevent this type of attack? I can't find any documentation.


texts:
I'm planning to store some bitcoins in cold storage. I'm doing a very simple setup, no complicated algorithms, no wallets...

Here is my plan

Create an air-gapped machine with a Linux distro. The machine won't have access to Internet and I'll disable wifi/mobile connection on purpose to be sure that no Internet is available.
Copy 4 files to the air-gapped machine using a microSD card. The first archive has a version of "coinb.in" which will help me create transactions. The second archive has a "bitcoin.sh" file which is a set of bash functions to create bitcoins addresses. The third archive, is a small HTML/JS qrcode generator. The forth file is the diceware words list.
On the air-gapped machine, create the mighty bitcoin address. I'm going to use a brainwallet with the following format (or a variation of it)

  SALT (5 char) + 10 Diceware words + My Password (10 char) + SALT (5 char)

The passphrase will be hashed one time with SHA-256. The resulting Hex. will be used as the private key. Generate the address/public-key with the bitcoin utility.
With the Qr-Code generator, create a qrcode of the bitcoin address. Now I use my mobile phone to scan the QrCode and send a few millibits to that address.
Using my connected laptop, I retrieve the Transaction id and Script of the transaction that I made. I write those down on paper. I then go to my air-gapped machine and I enter these information to create the transaction and sign it.
Once signed, I use my qrcode utility again to create a qrcode of the transaction raw HEX code. I then use my mobile phone to scan that QrCode and send it to my pc.
I check that the transaction is valid and I broadcast the transaction.

Some precaution I'll be taking:

Make sure that the Wifi is not running when the air-gapped machine is running.
When scanning the QrCode, make sure that the private key is not visible somewhere in the screen.

So this is the setup that I implemented. I'm wondering if I missed something or something is possibly at risk. Since the setup is tested, I'm here referring to the problem of funds being stolen by cracking my passphrase or infecting my air-gapped machine.

Ideas and critics welcome!


texts: Why did my BCC disappear from my Electron Cash wallet?

texts:
I use electron cash to manage my BCC, I followed the instructions of electrum.org and sent my BTC from my electrum wallet to a new BTC electrum wallet. I waited for the transaction be completed, then I used my old seed now empty of bitcoins to export to the electron cash, and my BCC appeared in my new BCC wallet. I made two small transfers of my BCC to Bittrex and the transaction was ok, at this point everything was ok.

When I do the transaction my electron cash BCC wallet start to synchronize and all the rest of my BCC (ALMOST 90%) in my Electron wallet just disappeared, the BCC wallet shows the last transaction of BTC but nothing about BCC, even the two small transactions of BCC disappeared from the transaction history. Now my BCC wallet is completely empty, what happened? Sounds like some interference between the two blockchains, can someone please help me find my BCC? Thanks


texts: Post Bitcoin mine reward: Lowering Difficulty an Option?

texts:
Maybe my understanding of blockchain, and Bitcoin need to be refined and will allow help me understand why my question wouldn't make sense in the grand scheme.

But first Ill establish my core understandings of the current concept...

With each leading zero added for a hash to be accepted in Bitcoins blockchain, it becomes increasingly more difficult (16 times more difficult) to find an acceptable nonce, thus mine a block.

I understand that the reason these difficulties were built in were to balance the amount of compute power with how fast blocks could be mined and rewards dispersed. This not only ensures there will be rewards long into the life of the coin but also ensures the coin was not devalued by having a "too easy" mining method as it grew in popularity.

In addition, as the difficulty of mining a block increases, reward decreases, the transaction fees also increase. This incentives miners to continue mining blocks and ensuring transactions can occur long past the last reward block mined.

My question is...

In the interest of everyone involved, wouldn't it make sense if the system was built to lower the difficulty after the last reward block was mined?

If that were the case, transaction times could be increased and become much easier to mine. Meaning transactions could cost less, be faster for miners without effecting the value of Bitcoin it self.

Thoughts? Am I missing something big that would make this an impossible concept?


texts: Can an SHA256 hash be used as an ECDSA private key?

texts: Is it possible to map a pass-phrase directly to a Bitcoin private key by using its SHA256 hash? I remember reading somewhere that not all 256 bit values are valid ECDSA private keys. If so, how can I make sure that the resulting hash is valid, or is there some other canonical way of mapping a pass-phrase to a private key?


texts: No longer receiving inv messages from node


texts: Getting error while accessing bitcoin client from ruby using Rpc

texts:
I am getting the following error while trying RPC call from ruby. bitcoind server is running. I am using bitcoin-ruby library .

Code Tried in irb to test:

require 'bitcoin'
=> true
irb(main):002:0> txid= "611b40973fe68cc42b70ae5af365a449af458d76086415c6fa6c45364c36278e"
=> "611b40973fe68cc42b70ae5af365a449af458d76086415c6fa6c45364c36278e"
irb(main):003:0> rtx= bitcoinRPC('getrawtransaction',[txid])

Error :

NoMethodError: undefined method `bitcoinRPC' for main:Object
    from (irb):3
    from /usr/bin/irb:11:in `<main>'

Any suggetion will be highly appreciated.

Thanks in advance,

R


texts:
I am messing with the Bitcoin sourcecode.

Normally when you want to send some BTC you type :

./bitcoind sendtoaddress 1ADRESSS 0.001

How would you do this in the sourcecode on a recurring basis?

So what code is needed to send a transaction to a specified address each time a block is created? Almost like a tax. and where would this code be placed?

I am learning the Inside of the Bitcoin protocol and C++ so any help would be great.


texts:
Is it technically possible to create and use dynamic private key - public key pair and use it with bitcoin?

I am not sure anything conceptually similar to this already exists. Yet, "dynamic" private - public key pair can be defined as ordinary key pair with 2FA capabilities. Both the keys regularly change per generated 2FA token.

Basically I hope the following,

create dynamic private - public key pair, combining 2FA (like, google authenticator) and a passphrase
this key pair can only be used for a short defined duration, or as long as 2FA token is valid
receive funds
chronologically old key pairs can be used to check / receive funds (or, not)
In future, private key generated from passphrase and 2FA token can be used to spend the coins

BIP 38 is not anyway related to this.


texts: How long does a payment take to appear in my wallet, If not how do I reacieave it?

texts: Yes how long does it take for a payment to appear in my wallet, on Bitcore, if it doesnt how do I reacieve it? Because it's been 15 hours but still havent seen it


texts: If SHA256 were compromised tomorrow, would Bitcoin collapse, or is there some contingency plan to move the network to a new hashing algorithm?

texts:
Hashing algorithms have a long history of becoming widespread and then declared insecure - MD5 is a good example. As Bitcoin increases ever more in popularity, and cryptanalysis becomes ever more sophisticated, there's sure to be a lot of interest in finding holes in SHA256.

Should this happen in, say, the next 10 years, will the network be ruined? Or is there a way that the network would be able to adjust, i.e. by slowly phasing in a new type of block and phasing out SHA256?


texts: Does merkle root contain hashes of transactions from previous blocks?

texts:
Every block in a blockchain contains merkle root value. So for any block, there is some list of transactions and you create a merkle tree based on these transaction.
For other blocks, same process will repeated.

My question is:
Let us assume that A, B,C,D are transactions and we create a merkle tree and we add the merkle root in block. Now later we got the transactions E,F,G,H so:

whether merkle tree is based on E,F,G,H only
or it is based on A,B,C,D,E,F,G,H .

I want to know that for some block, we created a merkle root value based on A,B,C,D. For others block whether we include previous transaction with new transactions  and create a merkle tree. Or with only new transactions, merkle tree is created.


texts: Why does getNewAddress take so long? Often times out python-bitcoinrpc

texts:
Bitcoin 0.11 on a Raspberry Pi 2:

https://github.com/jgarzik/python-bitcoinrpc

I am using this RPC auth proxy to talk to bitcoind from Python. I have a script that requests getmempoolinfo every 1 second. Occasionally given user input a new address is needed, and the script requests getnewaddress. This RPC-call often times out.

Sometimes the time-out causes even weirder behavior in other RPC calls until python is interrupted and the script killed: for example, getmempoolinfo returns the same information every time it is called until the script is restarted. Even querying bitcoind from the command line in a separate terminal window bitcoin-cli getmempoolinfo indicates that the mempool is not growing at all until the script that timed-out calling getnewaddress is terminated.

I also notice from the command line bitcoin-cli getnewaddress can take up to 30 seconds, without any python scripts running or other in-progress RPC calls.

I thought bitcoind is just retrieving a new address from wallet.dat, what is taking so long? It's not decrypting the wallet, it's not generating a whole new address from entropy... yet this specific RPC call is causing me lots of downstream problems.


texts: Encouraging virtual exchange and independance from hard money?

texts: With all the talk of economic sustainability and the dangers of infinite growth how do you think a virtual currency could be used to encourage the trade of virtual goods ? Or possibly a more efficient use of natural resources.


texts:
I was looking into omni protocol and couldn't quite figure out some things. I'd really appreciate your opinions. I tried to look into all the bitcoin stachexchange answers, but nothing that much related to what I am asking.
At first, I thought that Omni was a whole new blockchain(they forked it from bitcoin), and then added some more code to implement contracts so that assets could be transferred.
At second, I read that omni does write data to bitcoin blockchain itself.
Question 1) why is not the omni a new blockchain at all if they forked it from bitcoin ? we can see that on github.
Question 2) let's assume, it's not a new blockchain - then this means that my second thought is correct. How does it write data to bitcoin blockchain ? I can think of one way: P2SH Scripts, but wanted to make sure.
Question 3) if the omni is not a new blockchain at all, then how does its explorer work ? I guess, their explorer fetches all their related P2SH Scripts from bitcoin itself . right ?


texts: Why do the biggest exchanges reuse Bitcoin addresses if doing so is unsafe?

texts:
It's generally accepted that using one address for multiple transactions is unsafe, because sending a transaction reveals your public key (whereas only the hash of your public key is required to receive transactions).

If this is actually a safety concern, why do the biggest exchanges like Binance reuse their core storage addresses for many months, storing hundreds of millions of dollars? For example, Binance cold storage has 100 transactions:
https://blockchain.info/address/16ftSEQ4ctQFDtVZiUBusQUjRrGhM3JYwe
and Binance hot storage makes hundreds of transactions every day:
https://blockchain.info/address/1NDyJtNTjmwk5xPNhjgAMu4HDHigtobu1s

As a side question, in theory everyone knows the public key of these addresses since they have outgoing transactions. Where is this information written? I can't find it on the transaction page of Blockchain.info:
https://blockchain.info/tx/4d5b7175b4553d3239dae830837045adbe880b3d57dfc0c59a1bb8e6991b8ff8


texts: I signed up for bitcoin ages ago, but never used it; I forget who I signed up with I have had to reinstall the OS (Win 10) on my computer and lost the program I used. I do still have a copy of the address though. How do I add the address to MultiBit?


texts:
Hi so I used the following bash script to set up bitcoin on my centos server https://gist.github.com/cdodd/f485b72aed8c2a6440a6141cd1ba8273?signup=true

however i don't know how to get a wallet or create a wallet and everytime i try I get the following error, their is no config file and I am not sure where one is meant to be located. could someone please help point me in the right direction to install bitcoin correctly and create my own wallet.

Thanks

./bitcoin-cli -testnet getwalletinfo
error: Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not se
t.  See -rpcpassword and -stdinrpcpass.  Configuration file: (/root/.bitcoin/bitcoin.conf)


texts: btcchina how to deposit with mastercard?

texts:
https://vip.btcchina.com

I'm trying to "Fund CNY" to use in my bitcoin trades.
The problem is, whichever bank I choose, it redirects to a login page asking for a password or mobile payment option which I don't know how to use.

I only have the mastercard payment option. How can I fund?


texts: Stable bitcoind build with watch-only wallets

texts: I found out that the new major release of bitcoind will contain support for the watch-only wallets: https://github.com/bitcoin/bitcoin/pull/2861. Anybody knows if there is available a binary package consisting of current stable version with this pull request merged in?


texts:
I just found this gem - Discouraged Block. It proposes a method where miners "will" (are requested to?) ignore chains with certain blocks at the tip.

It's not like anyone can dictate the behavior of all miners, but if large parts of the network choose this discouragement strategy, then it becomes unprofitable for any single miner not to join in.

Are any current miners/pools for or against this discouragement policy (currently, the only policy is "ignore forks where the coinbase of the block at the tip does not contain the block height")?


texts: When installing libbitcoin is there an option to deactivate the warnings?

texts:
When installing libbitcoin from here with $ ./install.sh --prefix=/home/me/myprefix --build-boost --disable-shared after most of the compilation is done there are checks of the sourcecode with warnings like this one:

In file included from ./include/bitcoin/bitcoin/machine/operation.hpp:159:0,
                 from ./include/bitcoin/bitcoin/chain/script.hpp:31,
                 from ./include/bitcoin/bitcoin/chain/output.hpp:28,
                 from ./include/bitcoin/bitcoin/chain/output_point.hpp:25,
                 from ./include/bitcoin/bitcoin/chain/input.hpp:27,
                 from ./include/bitcoin/bitcoin/chain/transaction.hpp:30,
                 from ./include/bitcoin/bitcoin/chain/block.hpp:31,
                 from ./include/bitcoin/bitcoin.hpp:24,
                 from test/chain/transaction.cpp:20:
./include/bitcoin/bitcoin/impl/machine/operation.ipp:136:15: warning: ‘size_t libbitcoin::machine::variable_uint_size(uint64_t)’ defined but not used [-Wunused-function]
 static size_t variable_uint_size(uint64_t value)
               ^~~~~~~~~~~~~~~~~~

I was under the impression that the compiling was already finished and this is something that comes afterwards. During this process, which took half a day, my Pi runs out of HDD swap (1,7GB) and crashes. Is there an option to deactivate those warnings?


texts: Is there a way to to export/copy wallet's XPUB from MultiBit HD wallet (windows)?


texts:
I understand that to mine a block, miners solve a cryptographic problem and the solution can be easily verified by other nodes on the network, appending the new block to their blockchain.

But why do miners consent that some other miner managed to mine a valid block before them?
Why don't they claim that some other miner's block is invalid even if it actually isn't, and buy time to mine one themselves?
Is it because all non-miners will validate anyway and miners don't want to risk having a discarded chain?


texts: How do Cloud Mining Websites Divide Profits?

texts:
I have a simple question. Suppose that I sign up with some cloud mining service. I would like to know a bit more about how the system works. Let's say that the cloud mining service I use has n users, N = 1,...,n}, each user i contributing w_i> 0 CPU cycles to creating the block. In order to complete a block, T cycles are needed (this is a simplification, I assume that the number of cycles needed is a random variable; however, you can reasonably talk about the expected number of cycles).

We managed to create the block and got a reward R for it (R = 0 is reasonable, that just means that resources were committed, but we failed at getting the block).

How is R shared? Is it proportional to the number of cycles? Is it just equal division? Is there a more clever method involved?

Bonus question: what is normally the ratio between the amount of work invested and the actual work needed? Is it the case that the number of cycles committed is much greater than the number of cycles needed? Is there even a need to commit cycles, or is it the case that once a block is done, the pool moves on to mining another block?

I have tried to find an answer online, on the websites of the big cloud mining companies, but all they offer are promises of revenue, rather than an explanation of the revenue division mechanism.


texts: Someone else created a wallet for me to use. Is this a scam?

texts:
Someone on social media is offering me to mine bitcoin and they take 10% of any profit I make. I started talking and long story short I was told to download blockchain wallet app.

They provided me the login credentials and I was told once I login to change my password etc. Does this sound like a scam or legit? I mean about them giving me a user id for a blockchain wallet app and I gotta buy bitcoins, transfer them to this wallet and they will mine bitcoins.

Variant:
The attacker requests that the user creates a new blockchain wallet and then shares the login credentials instead of creating the wallet for the user.


texts:
I have a cuple of questions about how wallet creation works. If I create a Bitcoin wallet offline, is there any way of like validate the new wallet, I mean, what if this wallet already exist? I know the posibilities are incredibly low.
And, if I create an address offline, how Bitcoin nodes would accept my address as valid (or this isn't needed?) I mean, in which moment, Bitcoin nodes accept my offline-created address.
I have create a script that creates bitcoin wallets, and I create one offline, then I search for that address on https://www.blockchain.com/explorer and it shows my current address, so my question is how this address appear in this web?


texts: Coinbase IPN test page not posting data?

texts:
On Coinbase under Merchant Profile I'm entering the URL:
https://www.scirra.com/handlers/coinbasecallback.ashx

For the IPN tester.  This ashx page has the code:

var r = "";
foreach(string name in context.Request.Form)
{
    r +=(name + " = " + context.Request.Form[name] + "

");
}
r += "

" + context.Request.QueryString;
Amazon.Emailer.SendEmail("xxx@domain.com","xxx@domain.com","Callback Dat", r);

The email I receive contains absolutely no data, although the logs page on Coinbase implies it's posting JSON data and returning HTTP 200 (success).

Am I doing something wrong?  Or is this a broken feature?  Can I (semi) safely assume that it posts the JSON in live mode?  And if so, do I simply Request.Form[0] to retrieve it or does it have a string index?

Thanks for any help!


texts: how to send money using json-rpc in bitcoin-cli for php?

texts:
$bitcoin->sendfrom($this->session->userdata('account'), $_POST['address'], number_format($_POST['amount'], 8));

but this isn't working. i got everything via json-rpc. but can't send or move money using  json-rpc. what is the problem?


texts: What are the advantages/disadvantages of a continuously decreasing block reward compared to the current method?

texts:
The current method to control the bitcoin supply to a maximum of 21 million BTC is to reduce the block reward (currently 50 BTC/block) by 50% every 210000 blocks. In this forum post there is a discussion about "why doesn't the block reward decrease continuously?".
The OP writes:

So I personally wish that Satoshi had instead implemented a continuous block reward decrease.  With that approach, the reward will decrease ever-so-slightly with each successive block but still converge to 21 million.  That would avoid potentially disruptive discontinuities.  It's too late to change that now but, still, does anyone know why he chose a block reward function that looks like a staircase rather than a smooth curve?

This gets rid of the discontinuity (block reward going from 50 to 25 BTC) at the 210000 block mark and at each subsequent block reward readjustment. Would this be better than the current method? Are there other advantages to this method? Are there any disadvantages to a continuously decreasing block reward?
One disadvantage I can possibly think of is that this would favor "early adopters" even more than the current bitcoin implementation.


texts: History behind the scripting language in Bitcoin?

texts:
What is the history of the current existing scripting language in Bitcoin?

Satoshi's original whitepaper on Bitcoin makes no mention of a stack based scripting language. So who was the first person to propose this idea and implement it? And why did they decide to choose a stack based language?


texts:
i have lost a bit of coins using Bitcoin Core wallet.
I have send my coins from Bitcoin Core wallet to my address on Bitstamp(copy/paste,no mistake here) and on my Bitcoin Core wallet has said "sent" as allways...than my computer crashed and there was no way of fixing it other than format an re-install Windows. I know it was stupid not to have a backup of wallet, but it is too late for that. I tryed to find the transaction using the addres i have send to, but there is no transaction found.
I have no other info about my wallet, except a couple of addresses that i have generated on my Bitcoin Core wallet, when i was sending coins to my Bitcoin Core wallet.
Is there ANY way i can get my coins back?
And if not where are thay?
Will pay a finders fee :)


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

texts:
I have a question concerning Java and sha-256.

I try to do these steps discribed here to create a WIF key:
https://en.bitcoin.it/wiki/Wallet_import_format

step:

  String string
  = "0C28FCA386C7A227600B2FE50B7CAE11EC86D3BF1FBE471BE89827E19D72AA1D";

step (ad 80 in front):

  string = "80" + string;

perform sha-256:

here is my mistake. I can perform sha-256 on step 2 but the result is wrong. The reason seems to be perform the hash on a String and not on binary.
I get:

  e2e4146a36e9c455cf95a4f259f162c353cd419cc3fd0e69ae36d7d1b6cd2c09

But I should get:

  8147786C4D15106333BF278D71DADAF1079EF2D2440A4DDE37D747DED5403592

I dont get how to convert it to binary. Can someone help me?

Its the same problem as here (Correct way to convert a 256-bit private key to WIF?) but I dont understand the answer. I also cant reply to the thread because I dont have enough reputation.

Thank you :)


texts: How to find one private key from the list of 15 million public keys for the sake of experimentation?

texts:
Recently found a list of compressed public keys. The total number of 15 000 000 public keys.
Practical for all compressed public keys Balance: 0.000100 BTC

I do not set malicious goals. All just for the sake of interest and sports experiment I would like to try to find at least one private key from this entire list?
For the most part, I want to understand, apart from "Brute Force" (which will not help), are there more promising methods and ways of finding a private key?

Is it possible to search for a private key? Or are there some mathematical attacks, even when you know a large number of public keys?


texts: How can one see if an address is multisig?

texts: Some addresses on this page indicate whether the address is a multisig, and what the threshold signature scheme is. How do they detect this?


texts: Building libbitcoin libraries on Arch linux fails

texts:
I'm trying to build libbitcoin libraries on Arch linux.
First I tried to download AUR packages. I successfully installed libsecp256k1 and libbitcoin. But if I try to compile libbitcoin-system and libbitcoin-database, compilation fails. The problem is conflict between libsecp256k1 and secp256k1 packages. The first is dependency of system and second of libbitcoin. If I trick the checking of secp256k1/libsecp256k1 library presence, the compilation fails on unit-testing. I'm also quite confused when looking on AUR repository. There is always  and -git (e.g. libbitcoin-database and libbitcoin-database-git). I tried every possible combination, but was never successful.

I also tried to download sources from github. First of all: I don't know whether to run standard ./autogen.sh && ./configure && make -j4 && sudo make install or rather sudo ./install.sh.

Again I successfully installed library secp256k1 and libbitcoin using the first approach, but when running ./configure in libbitcoin-database, i get error

configure: error: Package requirements (libbitcoin >= 4.0.0) were not met

Please has anybody successfully installed libbitcoin libraries on Arch linux?


texts:
Satoshi Nakamoto wrote the theory about Bitcoin in his paper, but did he (or they) also launch the Bitcoin blockchain?

Like: Peter Higgs founded the Higgs particle in theory, but he didn't find the actual particle...


texts: Are there any blockchain inspection tools/libraries?

texts:
I am going to write software that gets information from the blockchain directly.

Are there any tools or libraries to speed up that process? I am looking for things like decoding and encoding transactions, verifying signatures, scanning for certain data etc.

Preferred languages: Python or C/C++.


texts: Why dont' nodes change the block version number when the nonce overflows?

texts:
After computing 4 billion nonces, the miner is supposed to update the merkle root.

Why don't they choose a new nonce and assign it to the block version number and begin again?

It would save time and improve an ASIC.


texts: Time it takes to Transfer btc from exchange to another wallet?

texts: I recently sent a small amount of btc from the exchange to my other bitcoin wallet and it hasn't shown up yet, can anyone give me info regarding delays and how long such a transfer can take?


texts: How does lost BTC affect the market in the long run?

texts:
I bought some bitcoins in 2012 and forgot about it. Now years later I discovered that the company who maintained the wallet went bankrupt and their website no longer works.

I therefore have lost access to my bitcoins forever.

I assume my story is not the single case where this happened.

As there is a limited amount of bitcoins, what will happen as more and more people lose access to their wallets with time?

What would be the effect on the market?


texts: What are the trust assumptions in --assumed-valid in bitcoin core 0.14?

texts:
Please help me understand and distinguish the trust assumptions in the following three cases shown below. Specifically, please elaborate the attacks possible (even though completely theoretical) and trust sacrificed to get the functionality.

Case 1: Bitcoin Core before 0.14 without assumed-valid and where each node does complete signature verification.

Case 2: Bitcoin Core 0.14 with the assumed-valid blocks with signature validation skipped for blocks prior to release. This means that the block signatures are correct because bitcoin-core devs signed on it.

Case 3: (Hypothetical) : Bitcoin Core 0.14 with UTXO set which has the snapshot of UTXO database. This would be done in a similar way as assumed-valid. This would skip the complete IBD and be really useful for quickstart-pruned node.

I would like to know answers to the following 2 questions:

Q1) What are the possible attacks (even though completely theoretical) which are possible in case 2 but not in case 1. Please elaborate security-model change required to shift from Case 1 to Case 2.

Q2) What are the possible attacks (even though completely theoretical) which are possible in case 3 but not in case 2.
It appears to me that security model in Case 3 is same as that of Case 2. If I trusting core devs with signature-validation, might as well trust they give the correct UTXO set.


texts: Sent Bitcore (BTX) to my Bitcoin Core wallet (a bitcoin wallet) - anyway to recover the BTX?

texts:
Topic says it all. For some reason I thought the Bitcoin Core wallet was for holding Bitcore Coin (BTX) but obviously that isn’t the case! I sent Bitcore (BTX) coins to that wallet last night and obviously isn’t being recognized in the wallet.

Does anyone know if it is possible to recover the BTX from the Bitcoin Core wallet? The Wallet doesn’t think I received anything so not sure I can recover private keys from it that represent the BTX coins.

Any help would be greatly appreciated!


texts: Is it possible to delete received or sent transaction in your mobile btc wallet

texts: Please help me to delete transactions from my wallet. I looked everywhere and cant find any help


texts: Is the concept of paid prioritization in blockchain against net neutrality?

texts:
Since there are so many discussion about net neutrality, this triggered the question, especially since usually the proponents of blockchain and cryptocurrencies are also big proponents of net neutrality.

At least at first glance it seems true to me, the transaction fees present in most blockchain implementations => paid prioritization => no network neutrality.

Maybe there is some economic perspective that I am missing that makes this not true, or maybe that at least it resolves all the problems usually associated with an absence of net neutrality.


texts: What would a bitcoin quantum resistant address look like?

texts:
In an hypothetical future where a quantum computer is able to break the cryptography protecting the bitcoin private key, one of the solution would be to move our coins to quantum safe resistant address before it happen.

How could this switch look like, do every UTXO have to publish on the blockchain on which new quantum resistant address he is moving, and what would these address look like ?


texts: How is the transaction malleability issue being fixed?

texts:
With the upcoming release of Bitcoin Core 0.9, I am wondering how the transaction malleability issue is being fixed and what are the consequences of the fix?

It appears that transaction malleability is causing a few problems for the Bitcoin network:

The network is DDoSed by multiple apparent double-spends being relayed
Senders of the transactions need to avoid spending 0 confirmation transactions in case they become invalidated by malleability
When saving TxIDs of spent transaction for record keeping one has to make sure the TxID did not get changed later

Will all of those issues be addressed in the upcoming update, and if so, how will they be addressed?


texts: Can i use the same hardware mining for bitcoin and Zcash?

texts: I use bitcoin hardware mining. Can I modify the hardware to mine Zcash cryptocurrency or I should buy Zcash mining hardware?


texts: How to correctly sign a transaction? Error: 64: scriptsig-not-pushonly

texts:
I sent a transaction with far too low fee and it's stuck in mempool.

I'm trying to do a double-spend with a higher fee without any luck.

My wallet: 15Zz2KP5iA7oVarmtmBvb9ZHUmQaSFL9M8

Unconfirmed transaction: 0b0177688485922027b336c24e765fdea8dc03d2ad79f87019705f2ca9fb970a

I'm using coinb.in to create, sign and broadcast transaction but I get Error: 64: scriptsig-not-pushonly.

The transaction seems to be valid when I verify it.

Can anyone point my in the right direction for this?


texts: How to make genesis block transaction spendable?

texts:
I read this question Why can’t the genesis block coinbase be spent? . It says because of some quirk (the genesis block coinbase transaction is not added to the global transaction database) genesis block coinbase transaction cannot be spent.

How to add this transaction to the global transaction database ? What changes are needed to make this transaction spendable ?


texts: Are there any "slow" sidechains? What are the tradeoffs?

texts:
Are there any examples of sidechains which target a block time much longer than bitcoin? Could a sidechain be made "slow enough" such that the size of a proof (SPV proof?) for it could actually fit into and be verified by a mainchain bitcoin transaction with the currently-in-effect mainchain protocol rules?

I'm interested in learning more about how a sidechain with a targeted time between blocks of, say, 1 week, might work and/or if such a chain, if it existed, could be useful.

I'm specifically interested in proof-of-work sidechains that do not rely on any sort of federation (as such, Liquid and RSK would not meet this criteria at the moment, but I'm unaware of any other current examples of bitcoin sidechains), and I'm most interested in "slow sidechains," if any exist.


texts: How much are accepted shares on GUIMiner worth?

texts: I have just started Bitcoin mining and am using GUI Miner. I have an AMD 7870 OC edition that is mining for me. Currently i'm getting 380 mhash/s, is this good? Also how many of the accepted shares are worth 1BTC?


texts: I bought bitcoin from an ATM machine but the person I want to send it to didn't not see it

texts: this is the receipt I got but the address on it is different from the address I want to sent it to


texts: coinbase, where is my btc and will i get bch

texts: so I wasn't sure what would happen in the forking fork, bright spark that i am i sent my btc to coinbase from a multi bit wallet on 31st july, so far seen only by 1 peer, hasnt turned up in coinbase, will it? has the fork swallowed my btc? has coinbase swallowed any bch attached? can it be cancelled as it isn't showing on the chain  at present, would i still get any bch attached if returned to an old multi bit wallet only set up for btc? questions questions..please help


texts: How do Bitcoin balances work when an address is controlled by multiple parties together?

texts:
user1, pubkey1, 1.1 BTC
user2, pubkey2, 1.2 BTC
user3, pubkey3, 1.3 BTC
user4, pubkey4, 1.4 BTC

user4 sends 0.4 BTC to a 2-of-3 multi-sig account controlled by user1, user2 and user3 using P2SH.
The transaction is successful.
What is the account balance for user1, user2 and user3?


texts: In Litecoin every single block is mined every 2.5 minutes, double spending?

texts:
In Bitcoin it takes roughly 10 minutes for every block to be mined.
In Litecoin it takes 2,5 minutes.

2.5 minutes in Litecoin mean that transactions can be confirmed faster.
In Bitcoin these 10 minutes are not  coincidentally, it has been choosen also to prevent double spending.

Why does Litecoin allows 2,5 minutes and not, like Bitcoin, 10 minutes?
Is the probability of having double spendings in Litecoin not much higher when using 2,5 minutes ?


texts: I was assigned a wallet by "Hidden Wallet" onion site - my BTC never arrived cause its a scam. I have the wallet address and proof that it was assigned to me under username and password - Can I get my bitcoins back or send from that wallet to another ?


texts: Javascript Bitcoin miner is it even worth it?

texts:
I know that mining bitcoins via JavaScript is just pointless at this point in time, but is there any other altcoin that is worthwhile mining via a GPU/CPU via a JavaScript embedded into a web page?

Our website gets over 2 million unique visitors per day, with an average time of 5 minutes on site.

Is there anything we could do to get them to mine something in order to get even $0.005 per visitor? or is it basically impossible?


texts:
can I import btc electrum wallet into my coinomi mulit-currency wallet app?

They both use electrum servers and they both have seeds so it looks like they are a similar kind of wallet.

In electrum I have the option

File/Save Copy

This looks like it saves a file with no extension next to

/home/username/.electrum/wallets/default_wallet

Could I import this into Coinomi via

(Coinomi app) /Settings/Restore Wallet/RESTORE A WALLET

enter my electrum seed / recovery phrase and password...

Without loosing my coins?


texts: I keep reading these terms and I don't follow this everyday. Last I heard was that segwit was suppose to solve the block size debate. What are all these new terms like segwit2x and UASF?


texts: How does Open Transactions solve the double spend problem?

texts:
OT is based on digital cash. From the article:

  To tackle the double spending problem, the payee has to verify the
  coin with the bank at the point of sale in each of the transactions.
  This verification of the legitimacy of the coin requires extra
  bandwidth and is a potential bottleneck of the system especially when
  the traffic is high. The real time verification also means there is a
  need for the synchronization between bank servers.

This is not clear to me. Does the bank know who owns each coin? What exactly does the bank verify? If I try to send the same coin to both Alice and Bob, where exactly would this fail? What knowledge do any of the parties (Alice, Bob, the Bank) gain during this transaction?


texts:
According to Greg Maxwell mining pool consolidation had reached the point of 22 large pools, as of the Bitcoin FDTN. conf. Nov. 2015.

What is the state of the current situation?  Has there been a further worrisome decline in this metric?


texts:
I was wondering that a block (Here's a Block #506398)

It's nonce is 1,229,291,212 (A little over a billion), Then why does it take so long to mine a block because my system alone can do about 500 GH/s (500,000,000,000 Hashs per second), Which is very little in comparison to what an ASICs can do.

Then why does it take so long to mine a Block??

Thanks for your help!!


texts: Is there any way to test that a mining system is set up correctly (solo mining)?

texts:
I am running a full node and have written some mining software to learn more about how bitcoin works. I know that the chances of mining a block are basically zero given my hash rate, but I am curious if my setup valid just in case.
When I call:
bitcoin-cli getblocktemplate '{"rules": ["segwit"]}'

I get back the json template with the following capabilities and mutable
  "capabilities": [
    "proposal"
  ],

  ...

  "mutable": [
    "time",
    "transactions",
    "prevblock"
  ],

Given these values for capabilities and mutable will the network allow me to insert my coinbase transaction and submit a block? If I intentionally set the difficulty low and generate a block I get the high-hash response, so as far as I can tell the network is able to decode my block. Just looking for other ways to test and verify the setup.


texts: Are there any services that can reasonably guess what IP address a transaction originated from?

texts:
Are there any services/agencies running a large number of nodes so that they can guess the IP address of a transaction's origin?

I guess they would need to run tens of thousands of nodes. However it'll be useful in tracing stolen coins. Surely there must be some.

I have seen talks and papers claiming to do so but not found any such service.


texts: Invalid -rpcallowip subnet specification: *.Valid are a single IP, a network/netmask or a network/CIDR

texts:
I'm new and all this of bitcoin, but I'm trying…
I downloaded BitcoinCore and GUIminer, I made the configuration for solo minning (I created my username and password, I set Bitcoin client path) but when I tried to launch Bitcoin client as a server I got that message. What could I do?