texts: How do I catch the unconfirmed transactions?

texts: I'm catching all the deposit transactions with walletnotify and insert them into my database. Then on every blocknotify call I fetch all the transactions under 6 confirmations from the db and update them, specifically their confirmations. How do I catch the possible unconfirmed transactions, so the ones that got saved in the db when were first posted, but in the process were rejected/unconfirmed in the next 6 blocks. And also, I'm open to any recommendations on improving my existing system. Thanks


texts:
When you install this bitcoin thingy it takes like 6 GB of space from your computer. That's huge.

Why isn't there some kind of open source site that stores this info, and the client can access there when it needs to?


texts: Is it possible to win the Bitcoin lottery?

texts:
If you have a PC and you try casual solo mining on your PCs CPU is it theoretically possible to mine a block and get the full block reward if you get really lucky? I know this is extremely unlikely given the low hash rate of a CPU but is it possible?

I am just wondering is there any point having your pc running when your not using it.


texts: Bitcoin unconfirmed trasection to cancel

texts:
I am new to bitcoin. i use blockchain. info.
i sent vtc to a purse on 15.12.17, but i am stuck still there after 20days.
i determined to cancel the reanection.
please help me.
Transection ID: https://blockchain.info/tx/2bd29e84967f6ee9c392b8bb8cb4cadb7e1560604f92dfbd57d88268b6c99714

please help me to cancel this. Thanks in advance


texts: Where can one trade AuroraCoins for Bitcoin?

texts:
I have some AuroraCoins (AUR), minin' them on ghash.io.
I want to turn them into BTC and then use BTC (no USD!).

Some exchanging site?

Trust me, I've been Googling, Binging, DuckDuckGoing and others and found nothing.


texts: Can a bitcoin cold wallet become incompatible

texts:
(newby-question)

If I plan to use a cold wallet for longterm storage without following the news around bitcoin and my cold wallets application does not get maintained anymore in the meantime, can it be that I cannot access my funds in that wallet anymore or is this totally impossible?

Regarding that question is there a difference between a client that creates a seed of words and a client that creates a private key?


texts: Why does re-signing a message in bitcoin-qt produce a different hash

texts:
I just noticed that if you repeatedly sign the same message in bitcoin-qt, the signature changes.

Why is this?


texts: Can someone please explain FIBRE to me like I'm 5 and why is it useful?

texts: I read the website but they imply you already know why this is valuable. Can someone please illuminate me on this issue?


texts: What is a cost-efficient, fast and easy method of transferring btc between own computers?

texts:
I use a few computers and would like to perform bitcoin transactions from any of them. Thing is, I'm not very fond of the idea of paying the fee and waiting every time I want to transfer the coins from one computer to another. Is there any other simple, convenient, easy "out of band" method of transferring coins between computers?

(I realize an online wallet service would solve my problem but I really don't like the idea of trusting a 3rd party with my bitcoins)


texts:
Once MyBitcoin was thought to be a "solid bitcoin bank". Then it was hacked and a lot of people lost a lot of money there.

Is there another, secure alternative for storing Bitcoins except storing them on your own computer?

(Obviously correctly storing Bitcoin on your computer, with proper encryption and backup, will always be more secure because you don't have to trust anyone. Still, for a lot of people, an online Bitcoin bank is a must.)


texts: How does a proof of work limit of `~uint256(0) >> 20` translate into a difficulty of `1 / 2^12`?

texts:
In the Litecoin source it is written:

static CBigNum bnProofOfWorkLimit(~uint256(0) >> 20); // Litecoin: starting difficulty is 1 / 2^12

How does that compute? ~uint256(0) >> 20 is 0x00000fffffffffffffffffffffffffffffffffffffffffffffffffffffffffff. Hashes have an equal probability of being any given number, so the chance of getting a valid Litecoin hash (i.e. one that is smaller than this number) is 0x00000fffffffffffffffffffffffffffffffffffffffffffffffffffffffffff / 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff = 1 / 2^20, not 1 / 2^12. Is this a typo in the Litecoin source code or am I misunderstanding something?


texts:
Respectfully requesting to look into this transaction. Did it got confirmed or not? is been 5 days now.
Thanks
18MJieFJcDiFbAsvSxe5iCaBAYsikgJta6


texts: Why do dustcoin.com and coinwarz.com give opposite results of profitability?

texts:
It's been several days in a row that I go to dustcoin and see Dogecoin being listed as less profitable than either Digitalcoin and BBQcoin, with the latest being the most profitable.

But then if I go to coinwarz I see the inverse: Dogecoin is the most profitable, next Digital and finally BBQ.

The prices listed for them are not that different, nor is the difficulty - below the values. E.g. the values at the time of writing this question - first columns are from coinwarz and then the values for dustcoin:

coin   vs. BTC                diff.    vs. BTC   diff.
BBQ  0.000048 (Cryptsy)      4.3986 0.00005165   3.192
DGC  0.00036494 (Cryptsy)   11.3679 0.00035000   8.062
DOGE 0.00000031 (Coins-E)  286.6240 0.00000028 271.845

I would've thought that getting the profitability would be a straight away calculation, given the hashpower at your disposal vs. the avg. reward for a coin, plus the difficulty of it's network and the value it commands on the market.

So I can't explain why each site gives the exact opposite answer for these coins in particular - my inner cynic suggests at least one of them gets paid to artificially increase/decrease the profitability of some coins, but I find that hard to accept as well.

Any ideas?


texts: how does bitcoin solve the same chain replay attack?

texts:
Let's say I send 10BTC to Bob. I have 30 BTC. So after transferring, I should have 20.
Now, after I transfered 10, transaction can be copied and broadcasted to the network again by Bob(he might have somehow get it from pool or something). Which means that replay attack has just taken place on the same chain(I know that replay attacks happen mostly when there's a hard fork, but in this case, I am talking about the same chain replay attacks).
Ethereum solves it by having nonce field in each account.
Question 1) How does bitcoin solve this case without SegWit ?
Question 2) how does bitcoin solve this case with SegWit ?
Question 3) If the replay attack happens for hard fork case, did bitcoin implement the solution or not ? I know that it was BTC cash that created a solution and btc said they wouldn't do it, but i am curious what's the state on this now ?


texts: Send addresses in Bitcoin Wallet for Android

texts:
I have three addresses on my Bitcoin Wallet for Android, but when sending coins, I can’t find where to select which address I want to send from.
I set the second of the three addresses I’ve got as the main address, but when I sent some coins they have been sent from the first of the three.


texts: What is BitInstant's "spot" price when sending to BitCoin Address?

texts: Bitinstant hasn't replied to my "contact us" and customer service emails - does anyone know why they do not post a current exchange rate on their page? Has anyone used BitInstant, funding from Dwolla and paying out to a bitcoin address?


texts: Can we do Multisignature transaction for bitcoin_cash?

texts: I tried implementing multi-signature for bitcoin and it worked successfully. Is it possible to implement multi-signature transactions for Bitcoin_Cash?


texts: What does this blockchain.info error mean?

texts:
I added bitcoin payment to my website with bitcoin daemon, but one user is having an error with the blockchain.info API:

  Warning! this bitcoin address contains transactions which may be double spends. You should be extremely careful when trusting any transactions to or from this address.

https://blockchain.info/address/163cTKxPehxPi4nJ3oTHAso6eXWywfYr7N

Should I confirm this user's withdrawal, or should I block them? And what is significance of this error? If I use bitcoind to count confirmations, it's not dangerous to accept funds from such an address, right?? Thanks!


texts:
I am trying to connect to a bitcoin node using the ZMQ library for Java. the problem is that when I try to receive a response the code remains frozen. Returns nothing.

This is my code:

public class CBETest {

    private static final String TEST_URL = "obelisk.airbitz.co";

    public static void main(String[] args) {

       System.out.println("\t--- ZMQ ---");
       Ctx c = zmq.ZMQ.createContext();
       SocketBase s = c.createSocket(zmq.ZMQ.ZMQ_DEALER);

       zmq.ZMQ.connect(s, "tcp://"+TEST_URL+":9091");
       System.out.println("Connected!");
       int sent = zmq.ZMQ.send(s, "blockchain.fetch_last_height", 0);

       System.out.println("Sent: " + sent);
       Msg msg = zmq.ZMQ.recv(s, 0);
       System.out.println("Response " + Arrays.toString(msg.data()));
    }
}

The code freezes in the line Msg msg = zmq.ZMQ.recv(s, 0);. I am using the calls described here for the full node implemetation. Thanks in advance!


texts:
How is a litecoin address generated? What hashing do they use?

For example, bitcoin addresses are generated like so: https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses

I am looking for an answer like that but can't find it anywhere. Any litecoin searches turn up with bitcoin links.

Please do not give me Litecoin address generation sites or wallets to download. I want to know how I can manually program a litecoin address generator.


texts: How to use Electrum GUI and Daemon at same time in seperate shell?

texts:
I'm running electrum via gui,and when I use the console the Font is so small and I haven't found a way to increase the size of console output.

Is there a way to increase the size of text ?

If not is there a way to run the GUI and also run the console in a Bash Shell separate window that I can manipulate the text format ?


texts: When I have a problem running the bitcoin client, where can I go to get help?

texts:
Let's assume that either a bug report exists already, or the problem is unlikely to be caused by a bug.

What I know so far is:

This site will be appropriate for some support questions, and the mechanism for the site encourages peer review of each answer. Here's an example of a support question.
The bitcointalk forums have a technical support category that is likely to give a good response as there are lots of active users.

Where else might I get timely support? (paid or unpaid)


texts: I lost my wallet pass, but thankfully didn't have any money there. How do I reset this thing and get a new fresh wallet with a new password?


texts: Armory SecurePrint Code length does not match?

texts:
From the last question, I learnt that I could use the btcrecover for help. But it was such a long time since I last used the wallet that I could not get an address used from the wallet, and using the addressdb file may take hundreds of thousand more time.
But I remembered that I created some armory wallets some years ago, and made paper backups with Secure Code. And those wallets transferred some bitcoins to my lost wallet.
And thus recently I tried to import it back but find the Secure Print code wrong.
So I created another wallet for test, and found that the Secure Print code of the new wallet contains 11 letters, but my old wallets 13.
Is it because the version of Armory or something? Because although I cannot remember much, the 13-letter securecodes were used by all my backups...
Any advice is welcomed.


texts: Does selfish mining actually give an advantage in the absence of transaction fees, difficulty changes, and economic effects?

texts:
I am reading the Cornell selfish mining paper. In it, their main argument is that a selfish miner can increase the ratio of the blocks he mines relative to the honest miners. I do not dispute this. However, to my understanding, merely denying others their blocks does not help you; just because everyone else is getting fewer blocks doesn't mean you're getting more. (That is, everyone mining normally would be expected to get a certain rate, but if you suppress some of those blocks, then the total rate goes down. So denying others their blocks is not zero-sum; just because everyone else's rate goes down does not imply that your rate goes up.)

Here's a simpler explanation of my confusion. Consider this thought experiment. Let's say 2/3 of the miners suddenly quit mining, leaving it all to a miner who has 1/3 of the hashrate. We can all agree that this miner is at least as well off as a miner conducting a selfish miner attack. (The reason for this is very simple: he could just replicate the exact same strategy used by the selfish miner, except that the honest miners now have no chance of finding a block in this thought experiment.) Nonetheless, they can only mine at a rate of 1 block per 30 minutes, at least until the next difficulty readjustment.

So unless you're a sadist who just wants to make everyone else worse off, it seems that selfish mining gives no advantage, unless we consider at least one of these three factors:

Transaction fees. If you mine at the same rate and cause everyone else to mine at a lower rate (because a lot of their blocks get rejected), you are still finding blocks at the same time intervals on average, but since each block takes longer in general to find, it will include more transactions and thus more transaction fees.
Difficulty changes. If the difficulty readjustment occurs as you're performing selfish mining, then of course decreasing everyone else's share of the pie increases yours.
Economic effects. With fewer bitcoins being mined, all else being equal, a decrease in supply causes an increase in price. So the bitcoins you mine are more valuable.

Am I correct in concluding that without these three effects, there is no selfish mining attack? If so, then selfish mining is not a problem in practice, at least for now. Transaction fees are minuscule compared to the block reward, difficulty retargets are infrequent, and the amount mined each day isn't really that significant compared to the total number of coins in circulation.


texts: How is the hash target set and verified by all nodes?

texts:
As in the title - I understand that nodes look at the last two weeks of calculated hashes and adjust the difficulty to bring the average time to 10 minutes. But how exactly is this done?

In particular, all the nodes would have to agree on the same target, else a newly mined block would be valid for some nodes and not others. This seems like a problem of consensus (in the traditional sense, not the Bitcoin way) which is very difficult, isn't it?


texts: Is there some website that aggregates all the Bitcoin exchange prices so small businesses can find out the current market rate and react accordingly?

texts: I have a small business in doing repairs and I'm willing to take bitcoin, but i was wondering if there is a site that aggregates all the bitcoin exchange prices so I can get an idea of what price to charge in bitcoins to avoid the day to day volatility. Yes i know i can use bitpay, but I want to be able to just take bitcoin myself and come up with my own merchant rate that i choose and feel comfortable with.


texts:
Is there a trading bots that trades automatically and can also be hosted by the company that is providing the service?

I've found BTCRobot and Butter Bot. Any reviews on the validity behind these companies and maybe some personal experience would be more than appreciated.


texts: Which data should be used in order to detect addresses to be used for fraud?

texts:
I’d like to analyse bitcoin blockchain in order to detect addresses used for fraud, like money laundering. Since I cannot get any addresses info that was really used for fraud, I need to analyse which kind of address have tendency to be used for fraud.

Now, I’m just wondering which parameters I should use. I’ve tried to use period of transactions and average of transactions’ amount, but it seemed not to make sense. If you have any idea, could you teach that?


texts: Blockchain transaction message length limit

texts:
When I perform a transaction on the blockchain, I can add a message to the transaction, which will then exist forever in the blockchain.

Say for example I wanted to use the blockchain to store digital assets...

Could this type of information be encrypted and stored as a transaction message, and if so, is there any limit to the message length of a transaction?


texts:
I know the maximum transaction size for a BLOCK is 250,000 bytes. My question is a little different.

What is a recommended transaction size for best selection of the transaction by pools? For example say I have 500,000 bytes of transaction to send over the network. How should I chunk those transactions? 50,000 byte transactions? 10,000 byte transactions?


texts: How to send bitcoins with commission extracted from payment in PHP or bitcoind

texts:
First, I have simple problem. I want to send customer some bitcoins, but I dont want to pay fees for him. I'd like to substruct fees from payment, so all commissions would be payed by customer.

I thought it should be a simple and common problem for all merchants that making refunds to clients. But I googled for hours and could not find any detailed explanation on how to achieve this feature 'receiver-pays-commissions'.

Here some links that I found usefull, but still they dont have exact answer

How to create raw transaction in bitcoind

How to create raw transaction in PHP

How to calculate transaction size and fee

Simply put. I want to send some bitcoins away so that my account balance will be equal exactly 1.8000000. Now it is slightly higher:

Surprisingly this simple and common problem took hours of googling, so I'm making this question just to share solution with public, since I finally found it.

(Or at least I think I've found it, so critics and comments are very welcome.)


texts: Is the proposed "Miner Promise" method of accepting 0-confirmation transactions safe?

texts:
This thread proposes a method for miners to promise "that their next block/s will contain a specific transaction", and/or that "they won't mine a conflicting transaction".

If adopted by a large percentage of miners, this method is supposed to enable "relatively safe" 0-confirmation transactions (well, safer than today at least).

If wildly adopted, could this work?


texts: How are block rewards claimed in merged mining?

texts:
How do you claim a block reward on a merged chain?

If I understood it right: let's say you are mining Bitcoin and Namecoin. When you find the solution to a BTC block, you include a transaction in the block to give you a block reward.
If the hash of this block is also a solution for the Namecoin chain, where is the transaction giving you the Namecoin block reward? Where is the Namecoin address getting this reward? Or are Bitcoin addresses also valid Namecoin addresses?
And if you are only mining Bitcoin, can you claim the Namecoin block reward for a solved Bitcoin block afterwards?


texts: For example, how much would the fee be to send $350 to someone? The person is trying to tell me it would cost $270 for 225 bytes


texts: Does Bitcoin Core accepts uncompressed address generation?

texts:
So one priv key express uncompressed and compressed pub key.

Does the latest Bitcoin Core client accepts importing it to express uncompressed address? or it automatically express compressed address?

I have not noticed related parameter for compression options in getnewaddress and importprivkey.

Is this because compressed addresses helps reduce transaction size?


texts: How many BTC have been paid in fees, in total?

texts:
Is there a graph or some data points for the total BTC paid in fees?

I'm interested in total BTC as % of the issued BTC at various points in time as well.


texts: Do I have someone else's private key in my wallet, or has my wallet been compromised?

texts:
Apologies for the vagueness of my memory.

I started using Bitcoin in mid-2015. I believe I installed Bitcoin Core at that time but got bored waiting for it to sync the blockchain, so I instead used MultiBit

Last week (April 2017) I decided to migrate off what is now called MultiBit Classic, since it's no longer supported. I upgraded Bitcoin Core to the newest version, waited for it to sync the blockchain, and was surprised to see two transactions from October 2016, both involving the address 1QKcPYdiDfPgNH4dYnC99uZqTszU4gndnn.

Dumping my wallet shows this address was generated back in 2015, and is marked as "reserve":

[private key deleted] 2015-04-29T18:42:36Z reserve=1 # addr=1QKcPYdiDfPgNH4dYnC99uZqTszU4gndnn

I'm sure these transactions have nothing to do with me. I wasn't using Bitcoin in October 2016, and I don't believe I ever performed any transactions at all with Bitcoin Core. What's going on?


texts: Given a Bip38 encoded private key, Can you derive the address without knowing the password?

texts:
The title says it all. I have a private key that is BIP38 encrypted:

6PYVdYvBaMXD7bFNJwMh8DCTxcBQjzyPmqWDQDp2PBKYyFUACph7vzjeaN

Is there a way to derive the address from just that information?


texts:
I want to implement 2-of-2 multisig in bitcoinj, and I implement the methods which are used to sign the first time and the second time. But there is a bug that using the same key for the first signing and second signing can also pass the transaction verification and can be broadcast. Where the mistake is？

sign_first_time(Transaction spendTx, String firstkey,String redeemScript_String){
        ECKey key1 = HexToECKey(firstkey);
        Script redeemScript = new Script(hexStringToByteArray(redeemScript_String));
        Sha256Hash sighash = spendTx.hashForSignature(0, redeemScript, Transaction.SigHash.ALL, false);
        ECKey.ECDSASignature ecdsaSignature = key1.sign(sighash);
        TransactionSignature transactionSignarture = new TransactionSignature(ecdsaSignature, Transaction.SigHash.ALL, false);
        Script inputScript = ScriptBuilder.createP2SHMultiSigInputScript(Arrays.asList(transactionSignarture), redeemScript);
        TransactionInput input = spendTx.getInput(0);
        input.setScriptSig(inputScript);
       }

sign_second_time(String transactionString,String secondkey){
        Transaction spendTx = new Transaction(params, hexStringToByteArray(transactionString));
        Script inputScript = spendTx.getInput(0).getScriptSig();
        List<ScriptChunk> scriptChunks = inputScript.getChunks();
        List<TransactionSignature> signatureList = new ArrayList<TransactionSignature>();
        Iterator<ScriptChunk> iterator = scriptChunks.iterator();
        Script redeemScript = null;

        while (iterator.hasNext())
        {
            ScriptChunk chunk = iterator.next();

            if (iterator.hasNext() && chunk.opcode != 0)
            {
                TransactionSignature transactionSignarture = TransactionSignature.decodeFromBitcoin(chunk.data, false,false);
                signatureList.add(transactionSignarture);
            } else
            {
                redeemScript = new Script(chunk.data);
            }
        }
        Sha256Hash sighash = spendTx.hashForSignature(0, redeemScript, Transaction.SigHash.ALL, false);
        ECKey.ECDSASignature secondSignature;
        ECKey key2 = HexToECKey(secondkey);
        secondSignature = key2.sign(sighash);
        TransactionSignature transactionSignarture = new TransactionSignature(secondSignature, Transaction.SigHash.ALL, false);
        signatureList.add(transactionSignarture);
        inputScript = ScriptBuilder.createP2SHMultiSigInputScript(signatureList, redeemScript);
        spendTx.getInput(0).setScriptSig(inputScript);
        return spendTx;
    }


texts: I transfered money to Bitcoin Core wallet. Now, how can I use?

texts:
If I understand it right, I won't be able to use it till the BitCoin Core finish synchronising.

Is there anything I can do to use the money now? From the sender site transaction was completed succesfully: https://www.blocktrail.com/BTC/address/1CQcKeg9L4zAkNhVaKMntS9kTY8n1rpcqA

And I'm always out of disk space because of sychnhronisng.

1CQcKeg9L4zAkNhVaKMntS9kTY8n1rpcqA


texts: Distributing 1 satoshi to every user on stack exchange or some other online community

texts:
I'm curious if there have been any coins that has distributed coins to an entire online community like an air drop. Currently many online communities like stack exchange have public profiles and public User IDs. If someone was to catalog every one of these users and generate a bitcoin address for them, then sent them 1 satoshi on the lightning network, it would be an interesting distribution model.

Has any coin done something like this?


texts: How to Track if Payment is Received with API in Coinbase

texts:
I am using coinbase api https://github.com/coinbase/coinbase-php and I successfully created order button but I didn't found anything to confirm or track that I have received payment.

<?php
    require_once 'lib/coinbase.php';
    require_once 'config.php';
    $coinbase = Coinbase::withApiKey(Key, Secret);
    echo $coinbase->createButton("Bullion Products", "10.00", "BTC")->embedHtml;
?>

With this codes I am able to show Pay with bitcoins its showing correct values but just want to track with API that someone send me bitcoins so I'll do some action according to it.

Thanks


texts:
If I am correct, some transactions have outputs with "value" field equal to 0, and some even have all their output "value" fields equal to 0.
See for instance:
transaction 9173744691ac25f3cd94f35d4fc0e0a2b9d1ab17b4fe562acc07660552f95518
I wonder if this is a feature or a bug, and what it means to send 0. Any thoughts?


texts: Cannot Making Outgoing Payments with blockchain.info API v2

texts:
I CAN't do Making Outgoing Payments :-(
i use blockChain api v2 with local nodeJS.
I work with Laravel 5.4. I have VPS server.
I installed local nodeJS service to handle the calls.
I started work of port: node blockchain-wallet-service start --port 3030.
Then I logined to my wallet.

 $url = "http://127.0.0.1:3030/merchant/$guid/login?password=$mainPass&api_code=$myApiKey";
$ch = curl_init();
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_URL, $url);
$ccc = curl_exec($ch);
$json = json_decode($ccc, true);
 var_dump($json);

Here, I got a good answer:

array(3) {
   ["guid"]=> string(36) "xxxxxx-xxxx-xxxx-xxxx-xxxx..."
   ["success"]=> bool(true)
   ["message"]=> string(94) "This endpoint has been deprecated. You no longer
                             have to call /login before accessing a wallet"
 }

I can Create Wallet API, check balance, do Listing Addresses, do Generating a new address and do Address Management with positive answers.
BUT I CAN't do Making Outgoing Payments.
I got next answer:

 array(1) {
    ["error"]=> string(34)
    "Unexpected error, please try again"
 }

Who knews what would be the solution?
I must get Response:

 { "message" : "Response Message" , "tx_hash": "Transaction Hash", "notice" : "Additional Message" }

Thanks a lot!


texts: Why would anyone use a payment network based on an imaginary currency?

texts: Almost everyone who encounters the idea for the first time (including me) has the same reaction, that can't possibly work. But so far the market has proved the skeptics wrong.


texts: What prevents hackers from guessing seed phrases?

texts: If seed phrases are generated from a finite list of mandatory words, what prevents someone from randomly generating seed phrases that might work?


texts: transaction (s) not going through due to low fees selected

texts:
I'm having a problem with a bitcoin transaction (not through btcpay, but i don't know where else to turn to). I sent 0.06btc from my wallet to my father (20 hours ago), and stupid as i am, decided to be a cheap bastard and chose the smallest fees. The transaction hasn't gone through and i don't know what todo...
https://bitpay.com/insight/#/BTC/mainnet/tx/ea3536f6fc340a722633525eae720f2814da563fd3ca757c2736e2c92158327f
about 4/5 hours ago, my father activated the option from his side saying he would pay the necessary fees (so he says)  but still nothing happens...
Extra info: my wallet is Copay on iPhone and he's using Bitpay on android phone...
Please help me get my mind at ease, what is supposed to happen here? and in what time frame?
much appreciated for any information, even if it's just instruction on where else to go ask this...


texts:
Do mining pools expose attempted nonces to the public?
I would think no because it would be counter competitive.
I can let a giant mining farm tell me what nonces not to use.
But let's say the nonces attempted were public to everyone. Would it be faster to

continue attempting random nonces
storing the nonces previously attempted in memory and finding them in a sorted array

This is a 'Big O' type question.


texts:
I've seen a few questions about this already and they talk in generalities. I'm talking about specifics. If I start the bitcoin client from scratch, where in the source code does it actually add nodes.

http://bitcoin.sipa.be/seeds.txt seems to be a list of known clients, which is fine, but where in source does it connect. If I wanted to create my own private network, how would I accomplish this?

If there's just one client on the network, is that client still doing all of the work that bitcoin does? Mining, etc.


texts: What are steps 4-9 in bitcoin address generation for?

texts:
From a perspective of generating collisions, it appears that many of the steps outlined in https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses do not need to be computed by any would be attacker.

For any address which has spent an input, the ECDSA public key is in the block chain, rendering steps 2-9 unneeded to check for a collision.

For any address which has not spent any inputs, the RIPEMD-160(SHA-256(publickey)) is available in the blockchain, rendering steps 4-9 unneeded to check for a collision.

Thus, what purpose do steps 4 through 9 of the address generation serve? Why not simply BASE58(0x00 RIPEMD-160(SHA256(publickey)))?


texts: How to make sure, Bitcoin private key and bitcoin address generator tools are generating valid key pair?

texts:
I find lots of tools/scripts written in python which can generate random number then using this random number it generates Bitcoin Private key(WIF) -> Bitcoin Address pair.

I have tried verifying few pairs using www.bitaddress.org >> Wallet Details by entering WIF key and verifying with output address.

But How can one make sure, the tools/scripts will always generate valid address and key pair ?

or is this like this way

if it generates one valid address and key pair it means all the future address and key pairs will be valid ?

i was looking at this https://github.com/shirriff/bitcoin-code

from makeAddr.py

import random, keyUtils
private_key = ''.join(['%x' % random.randrange(16) for x in range(0, 64)])
print keyUtils.privateKeyToWif(private_key)
print keyUtils.keyToAddr(private_key)

i know random number/string generated using this method is not very much secure, but i am talking in terms of valid WIF and address pair.


texts: How do I Transfer Bitcoins If I have a watch-only account with the Private Key

texts: How do I transfer bitcoins over from a watch only electrum account if I have the private key and its address?


texts:
Let's say I have wallets A,B,C.
A funds multisig address with B and C.
B & C show keys, get input and spent it to OP_RETURN transactions.

Is it possible?


texts: How can I migrate from blockchain wallet to Electrum?

texts:
I would appreciate a simple step-by-step guide to migrate from Blockchain wallet (https://play.google.com/store/apps/details?id=piuk.blockchain.android) to Electrum wallet. Presumably I would have to use my blockchain.info wallet seed words to create a new Electrum wallet. Is there a step-by-step guide for this operation?

Thanks

P.S. I am not allowed to use "migration" and also "Blockchain Wallet" tags because I am a newbie


texts:
I have problems starting up C-lightning's lightningd on Debian Buster under vagrant.
Steps I followed:

Fresh install bitcoind
Install lightningd
Run rpc commands - all good.
Reboot system
Get the error

Following is the output of lightnind after reboot:
2020-07-20T02:59:44.639Z UNUSUAL plugin-bcli: Could not connect to 'lightning-rpc': Connection refused
2020-07-20T02:59:44.652Z INFO plugin-bcli: bitcoin-cli initialized and connected to bitcoind.
2020-07-20T02:59:44.730Z UNUSUAL lightningd: Waiting for initial block download (this can take a while!)
2020-07-20T02:59:44.732Z UNUSUAL lightningd: Unable to estimate opening fees
...
2020-07-20T02:59:44.732Z UNUSUAL lightningd: Unable to estimate max_acceptable fees
2020-07-20T02:59:44.925Z UNUSUAL plugin-bcli: bitcoin-cli getblock 00000000000000ad6082acfe902b2ee294f4d1219f12b67bf59f88bb9d4af729 0 exited with status 1


texts: How do light clients connect to the network?

texts:
I have a few questions regarding light clients (such as Electrum and Multibit).

Are they connecting to full nodes directly (using port 8333) or to another kind of server on another port?
If they do not connect to the bitcoin network directly (on port 8333), why is that? Why is it necessary to be a full node (with the whole blockchain) to communicate in the bitcoin network?
In the case of Electrum, it seems to connect to an Electrum server, which runs a full node. What are the advantages of doing so instead of connecting directly to the bitcoin network on port 8333 (assuming that it would be possible)?


texts: When did the main Bitcoin client become known as Bitcoin Core? When/Why/How did this happen?

texts:
Afaik at some point in 2014/2015, Bitcoin became known as 'Bitcoin Core'. I assume this was to differentiate it from other implementations of Bitcoin.
When and how did this decision come about?


texts: Is the Electrum seed compatible with other wallets?

texts:
Apologies if this is a simple question - a newbie here!
I'm trying to understand backups. If I use Electrum to make a back up (including the 12 word seed password), will I then need to use Electrum to restore my BTC/ or can I use a different piece of software (like Exodus?).

What I mean is: are backups/restoring wallets dependent on the software you made the original back up on? or can you restore using any software as long as you have the 12 word seed?

I'm wondering about cold storage of wallets.

THANKS!


texts: Will Segwit embedded inside P2SH save fee compared to P2PKH?

texts:
How much transaction fee will Segwit embedded inside P2SH save fee compared to P2PKH?

Update 1

I found a similar question.

  or they can be nested in a legacy P2SH 3... address which are backwards-compatible (although less efficient)

He said less efficient. I want to know how much? Transaction size will be smaller than normal...?

How do transaction costs compare between Bech32 addresses and legacy Bitcoin addresses?

Update 2

I found another one. I'm reading it.

SegWit transaction fee/byte

Update 3

The following page describes block weight. P2SH is used in the example. I think P2SH-wrapped segwit addresses has benefit for cheaper transaction.

Block weight

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

Someone posted the following table. I don't know if it is correct or not. But seems segwit(p2sh) has benefit than I expected.

Quick table. Sizes in bytes (virtual bytes for segwit, including the segwit discount)

How do I calculate my fees for a transaction sent from a Segwit address?

https://www.reddit.com/r/Bitcoin/comments/7m8ald/how_do_i_calculate_my_fees_for_a_transaction_sent/


texts: What's the minimum age to join or use Bitcoin?

texts: What is the minimum age a person must be to use the Bitcoin service?


texts: What is the advantage of running a Ripple masternode?

texts:
There is one thing that I cannot stop wondering about:
Why would someone run a Ripple masternode?
Before you mark this as a duplicate, I understand how the transaction fees work in Ripple and also the mechanism of distributed consensus.
The point is - for other currency types, the usual rewards for providing services keeping them alive are transaction fees. If the masternodes don't collect any fees, what is the reason to operate one and bear the associated costs?


texts: Litecoin - mandatory-script-verify-flag-failed (Signature must be zero for failed CHECK(MULTI)SIG operation)


texts: Is it possible to run out of nonce values?

texts:
Miners can vary at least these things when searching for hashes:

A 32-bit nonce
Which transactions are included in the block.

Is it ever possible for a currency using the Bitcoin protocol to get 'stuck'? That is, can all combinations of parameters that miners are allowed to tweak not result in a hash that conforms to the difficulty?

One scenario using those parameters I listed could be an ASIC miner working on a brand new network. The difficulty should rise extremely quickly, but there would be very few transactions for him to work with.


texts: Using the Proof of Reserves utility developed by blockstream

texts:
I was looking into the various methods that can be used to generate the proof of reserves and came across the open source version created by blockstream to generate the proof of reserves( https://github.com/ElementsProject/reserves ).

However I am unable to use the utility as is and need some guidance on how to use it. According to my little understanding I may have to install a few softwares in order to run the utility. Can someone help me out? Pardon me if it is a stupid mistake/question as I am very new to bitcoin and am at a very very basic level.


texts:
I edited litecoin.conf file...

To this:

testnet=0
rcpuser=user
rpcpassowrd=pass
rpcport=9332
server=1

I use minerd with litecoind and when I try to connect to the local machine 127.0.0.1:9332 everything work fine. When I try to connect another workers from the LAN it cant connect to litecoind.

When I scan the port of the machine running litecoind, the port 9332 is closed.

How can I remote connect to the litecoind daemon via LAN?


texts:
My Bitcoin V 0.1 says, "not connected" when I try to generate coins. I have ensured the port is connected through the firewall. Also, I have read that V 0.1.3 corrected this problem. However, I am trying to connect without installing V 0.1.3.
Does anyone know how to correct a V 0.1 "not connected"?


texts:
How to retrieve unclaimed BTC for wallets whose private key is lost
Kindly share details


texts: How do I consolidate all my BTC into a single address?

texts:
I'd like to archive all my coins in a single address (specifically the address for a "brain wallet").

What is the most effective way to combine all the outstanding balances into a given address?


texts: Why Block351543 is older than Block351542?

texts:
I am a little confused here. Why the Age of older Block[351542] is younger than Block[351543].
Here is the screenshot from blockchain.info


texts: My bitcoin is in a platform where their website is down

texts: I have a question and looking for advice on what to do.  My bitcoin is stored in an account called Aptimarket.  The website for this company is in a redemption list.  Their domain is now under Namecheap.  I contacted Namecheap and was informed that Aptimarket is in a redemption list and might be deleted soon.  My bitcoins are in an account with Aptimarket and not able to get to my account.  I am concerned about this as where are the he bitcoins?   I’m sure I’m not the only customer who has an account with Aptimarket.  I can’t get into my account because of Aptimarkets website not active.  Any help on this or any information would be appreciated. Thank you.  Rose


texts: What does the US government do with seized coins?

texts:
It was reported today that the US government shut down the web site Silk Road, where people bought and sold things (allegedly including illegal drugs) using Bitcoins.  The operator was arrested, and BTC 26000 was seized.  (Source: New York Times).

A few months ago, it was also reported  that the US Drug Enforcement Agency seized BTC 11.02 from a person suspected of buying or selling illegal drugs.

Is anything known about what the US government (or any other government) does with seized coins?

Some possibilities:

Sell them on an exchange for USD, and turn the proceeds over to the Treasury
Sell them at public auction, as is commonly done with other seized property
Use them in future sting operations
Do not return them to circulation, but hold them indefinitely
Destroy them by transferring them to an address with no private key


texts: How could Schnorr signatures be aggregated across the whole transaction?

texts:
I am studying the MuSig protocol and am having trouble grasping certain segments. This is my understanding thus far:

In current Bitcoin CHECKMULTISIG format, the size of the signature grows linearly with the number of additional "m" signers. The way CHECKMULTISIG works is that each signer produces their own independent signature, and we embed all these individual values in the scriptsig. So, a 3 of 5 unlocking script might read [sig 1][sig 2][sig 5]...for simplicity sake I will be calling this compilation of all individual sig values the "group signature". In the given example, this signature field would be 3x the length of a standard P2PKH.

In a "naive" Schnorr multisignature scheme, rather than dropping all the potential public keys and [much larger] group signature onto the blockchain for verifier computation, we can have the signers interactively sum their individual public keys in a precommitment phase to derive a single "aggregate" key, that reads synonymously to a traditional public key. An outside member could then send BTC to this aggregate key, where it would be controlled by the group members. For the group to spend, each party would create a partial signature using their unique personal keys, and interactively sum all these signature values to create a group signature. At this point, we are left with a group signature (that is the size of a basic P2PKH sig) and aggregate public key being appended to the blockchain, providing us great space savings. However, this scheme is insecure unless operating under a KOSK model. We turn to another Schnorr variant, MuSig, that can offer provably secure key aggregation while operating in the plain public key context.

The 2018 Blockstream blog post states:

  Instead of restricting ourselves to one signature per input, we can actually get one signature for the entire transaction. Key aggregation can’t be used across multiple inputs, as the public keys are committed to by the outputs, and those can be spent independently.

I am having trouble understanding this paragraph. I am guessing that each aggregate key must be referenced in the scriptsig, since the previous sender's scriptpubkey would have mandated proof in order to unlock the encumbrance. I am struggling to understand how the aggregated signature across multiple inputs part is accomplished.


texts: When I use importmulti with an xprv it never imports the private keys. What am I doing wrong?

texts:
When I call:

bitcoin-cli getdescriptorinfo "pkh(tprv8iDvhA6eaMDbRuH3D2DTNuH6N6LvMTVrcv7z6sVxyyYvThSaCSa3i3qFVqUgVL4NbVkACxjx3KPWLoP5jvDU3i16hjTnzEFnZuqsnTJ5F4n/*)"

it returns:

{
  "descriptor": "pkh(tpubDEuxqa8tiiuGKNJq6ft3nJwCw7rrWngmCDimPPYGQFMKJBhLpqPdtYT7fzuDbk1AppxRdYjzeUrLaVNQRP7EYghzLDBMguY2LHHHeHMtzhm/*)#0wkkha79",
  "isrange": true,
  "issolvable": true,
  "hasprivatekeys": true
}

I then call:

bitcoin-cli importmulti '[{ "desc": "pkh(tpubDEuxqa8tiiuGKNJq6ft3nJwCw7rrWngmCDimPPYGQFMKJBhLpqPdtYT7fzuDbk1AppxRdYjzeUrLaVNQRP7EYghzLDBMguY2LHHHeHMtzhm/*)#0wkkha79", "timestamp": "now", "range": 100, "watchonly": false, "label": "Hot Storage", "keypool": false, "rescan": false }]'

It returns:

{
    "success": true,
    "warnings": [
      "Some private keys are missing, outputs will be considered watchonly. If this is intentional, specify the watchonly flag."
    ]
  }

I am importing an xprv because I want to import the private keys, but they always get imported as watch-only.

Why is this? Is it intentional?


texts: Does exist some library for decode/encode raw transaction?

texts:
I want to parse raw transaction into JSON then change some values and encode back to hex. JSON like this:

{
"addresses": [
    "346vcZZ6QV4nr68fybMEuA7qxxQeyKWoPS"
],
"block_height": -1,
"block_index": -1,
"confirmations": 0,
"double_spend": false,
"fees": 0,
"hash": "e09c37cca11208a8c372a1e397dcff0382b4d78cdde157ce8824d028dc185a80",
"inputs": [
    {
        "age": 0,
        "output_index": 1,
        "prev_hash": "c15bb773cdd5bb63a65766f5680684ce991c126698db0aa020e3058081742874",
        "script_type": "empty",
        "sequence": 4294967295
    }
],
"outputs": [
    {
        "addresses": [
            "346vcZZ6QV4nr68fybMEuA7qxxQeyKWoPS"
        ],
        "script": "a9141a75cd53e9740caadbf83cbefdd087cdceb978a487",
        "script_type": "pay-to-script-hash",
        "value": 14000000
    }
],
"preference": "low",
"received": "2018-08-21T08:05:02.841875145Z",
"relayed_by": "54.160.159.32",
"size": 83,
"total": 14000000,
"ver": 2,
"vin_sz": 1,
"vout_sz": 1
}

I've tried to use bitcoinj but it returns very simple object without a lot of fields.


texts: Can you please tell me if I launch a few actively working daemons bitcoin and point them to different -wallet, but the same -datadir will I have problems?


texts: When is there a charge for sending/recieving BitCoins and other CryptoCurrencies

texts: I want to transfer BitCoins from my local wallet (to a new wallet) and then 'extract' the BitCoin Cash to a different new wallet.  Will I incur a charge?


texts: Reuse of payment hash in Lightning Network

texts: Suppose there exist two such payment transfer request: A transfers 1 msat to R via A->B->C->R and S transfers 5 msat to R via S->B->C->R. Let the two HTLCs be formed across both the paths simultaneously and let both the payment use the same payment hash say H. Now channels B-C and CR has two HTLC using the same payment hash. As mentioned in https://github.com/lightningnetwork/lightning-rfc/blob/master/04-onion-routing.md#failure-messages it is stated that "An intermediate hop MUST NOT, but the final node: if the payment hash has already been paid: MAY treat the payment hash as unknown or MAY succeed in accepting the HTLC." It seems that R can release the preimage of H and settle both the payment if R has received both the HTLC request at the same time. However, is it so that R will settle one payment and fail the other so as not to encourage the reuse of hash?


texts: What are the chances of getting duplicate wallet using bitcoinlib in python3?

texts:
I am using bitcoinlib in python to create bitcoin wallet as shown here. My question is that how random private keys are which are generated by bitcoinlib?

For example Alice has private key '5ThisIsMyPrivateKey' which was created by some other program (bitcoin core, coinbase, hitbtc or anyone) and I am using bitcoinlib and I have a wallet for Bob and Bob's private key generated by bitcoinlib can be '5ThisIsMyPrivateKey'? What is possibility of it?

Another question is that is there a possibility of having same public key of two or more private key? I have seen lots of different private key structure when I was looking for information and I found three of examples where private keys starts with "5", "K" and "L" so is it possible that same public address can be created by using either of private key version?

I am still new here at encryption and bitcoin and I am just looking for information.

Thanks for your time.


texts: How can I access the mnemonic in the mobile copay wallet?

texts: I was encourage to download copay in my phone so that someone could give me 0.001 BTC. In that process I did not write down the 12 words. Is there a way to access them in the app? Thanks.


texts: What is the best practice for listening to payments on the RPC api?

texts: I have a docker instance running a bitcoin node and would like to listen to deposits, generating a new address each time a user requests to deposit then increment the users account balance on success.


texts: What is the formula to calculate the length of a merkle tree?

texts: What is the formula to calculate the length of a merkle tree, given the length of the leaf vector?


texts: Automatically Get Bitcoin Difficulty, Bitcoins/Block, Exchange Rate Statistics

texts: What can I do to programmatically get statistics such as current Bitcoin difficulty, Bitcoin award per block, USD/BTC exchange rate?


texts:
Hi i've built bitcoin core 0.15 from source and am trying to get it to run at startup.

I've used the bitcoind.conf file found in the bitcoin core repository
https://github.com/bitcoin/bitcoin/blob/master/doc/init.md

I'm also running Ubuntu 16.04 and am trying to test my upstart script i've placed in /etc/init by running service bitcoind start however I get the following error:

Failed to start bitcoind.service: Unit bitcoind.service not found.

The only thing i've changed in the example script is user to my user (sudo privileges) and the group to sudo.

Does anyone have any ideas?

Thanks


texts: Google Sheets Cryptofinance Add-on - is the company still operating?

texts:
I sent in some support emails since May 14 and have not heard back. Anyone aware if the developer is still operating this add-on for Google Sheets?

      Update, they replied today (May 23) and resolved my inquiry.


texts: Just received my profits from a "watch only" address, where do I obtain private keys?


texts: How do more leading zeroes make it more difficult to find a block?

texts:
A couple of articles describing the process of mining do say that the more miners are in the network, the more 0 numbers are included in the encoded hash of the particular block. I cannot find an answer to the following question:
why does adding more zeros at the beginning of the hash make it more difficult to calculate?


texts: Is there a way to query the blockchain locally if I am running a full node?

texts: I'm running a full node on my PC and wondering if there is a way to query the blockchain locally via NodeJS instead of going through blockchain.info? It is very inefficient/slow to run queries through HTTP when I have all the data local.


texts: Are NXT messages stored on the blockchain and are they encrypted or publicly viewable?

texts:
Are nxt messages stored on the blockchain?

What is the character limit on these messages?

And are the messages encrypted or publically viewable? If they are public, is there a site to just view all the messages sent?


texts: How do senior bitcoin devs plan to share their knowledge and experience with others?

texts:
I understand Bitcoin is open source and people contribute, leave at some point (planned or unplanned) and things must go on. There are few people after a decade who are respected for their contribution, dedication and focusing only on Bitcoin even if everyone said it can fail.
It will be wrong to mention few names because Bitcoin Core which is just one implementation exists and keeps improving because of effort from lot of people. However, few people have contributed more and their passion for Bitcoin is visible in the communications they still have after so many years.
Are there any plans to educate new devs so that we could have more such devs in future with similar skills and passion. This is about individuals and not the organizations some devs worked for or still working with. A C++ dev working on an open source project is different from a dev working on Bitcoin Core resolving an issue with C++ code and passionate about working for Bitcoin because of its properties and using it.


texts: TorBrowser + HTTPSEverywhere Blockchain.info wallet safe?

texts:
I seem to find conflicting information regarding the possibility of a TOR exit node stealing my data even while using HTTPS.  How possible/likely is this?

Let's assume user implements strong security on his personal system/network (no keyloggers, malware, etc.) and the blockchain.info is honest.  For this example, I am concerned about the attack vector of the TOR exit node even while using HTTPS.


texts:
I'm trying to sign a transaction using SSL. I already generated the raw transaction and hashed it properly. So I'd like to sign the following hash: c88568c9a85d52d07432dee9ee8dd1c63a4bfea6f754d2ec94f50015ae91a3f3, using the following private key: a16173978f25fcae5a1e55733fbda2f86470427e5cd9407c51b427c3054d182e.

I have looked around and figured the following command: openssl dgst -sha256 -hex -sign key.pem hash.txt. Great! (I think). How can I convert my private key to .pem file so SSL can use it to sign?


texts: Wallet.dat in the mobile hard disk is not backed up after sending Bitcoin, what can i do if the data recovery cannot found it? I have the original wallet.dat and private key， but there are no coins in it. help !!!


texts: How safe is it to use a Linux live CD to access my savings wallet?

texts:
It's clearly safe to create a savings wallet offline with a live CD, as no data can be sent to an attacker even if the live CD image is compromised (which seems unlikely).

However, when it comes to sending a transaction from a savings wallet, the client must be connected to the internet, so the risk increases. If you create a live linux CD, with an OS such as Ubuntu, it is out of date within a fairly short time of it being created as the live CD does not receive the latest patches that a permanent installation normally receives.

Presumably this means there's a chance (however small) that when you use the live CD and connect to the internet a security hole will exist that can be exploited to steal your wallet and wallet passphrase next time you enter it. How big is this risk? (Am I just being totally paranoid?!)

The severity of the risk is obviously a difficult thing to determine in the context of all possible live CDs, so perhaps a better question is this, if the first one is too difficult: have there previously been any security holes in live CD releases that allow an attacker to remotely control the computer?


texts:
Mark Friedenbach says "Bitcoin’s Block Size Can Be Increased Without Hard Fork".

Can someone ELI5 what are Forward Blocks?


texts:
I am using v0.11 rpc, In blockchain balance and my rpc balance are different. rpc balance is wrong why?
But transactions are correct.


texts: What would happen if a portion of the Bitcoin network was separated from the rest of the network?

texts:
Yesterday I asked a question over at SuperUser, so that I could have my facts straight before asking this question.  The scenario sets the basis for this question.

Regarding bitcoin, what would happen to the Bitcoin system if a portion of the world had it's internet connection severed with the rest of the world.  In other words if, say, all outside communication was lost in the region of Armenia, would the Armenian Bitcoin users, who continue to use Bitcoin, ultimately create a forked block chain?

If so, what would happen to the blockchain when connection to the severed region of the world is restored, and the segregated network is resolved to the primary network?

I imagine the outcome would be similar to a 51% attack.  Is that correct?


texts: Suggestion for Airgap Bitcoin Core - Comments?

texts:
Lesson learned the hard way: I lost a small value of bitcoins due to foolishly  backing up private keys to a file which was uploaded to a cloud server. My wallet used to be bitcoin core.

Right now my keys are in electrum with an air gapped laptop wallet and a watching wallet.

I'd prefer to use bitcoin core because having my own blockchain is preferable.

I know you can use bitkey, but as a Windows user, but it seems too complex.

I'm considering the following solution, and would welcome comments.

Currently, I still run bitcoin core with an empty wallet, on my desktop PC connected to the internet. The blockchain is on a separate SSD disk and I run the empty wallet to keep the blockchain up to date.

I would then keep a core wallet holding the keys to my coins, on the air gapped laptop. When I want to send or receive bitcoins I would move the SSD to the laptop. The SSD would use a SATA to USB connector, so it would be an easy plug in. As soon as I'd done the send or receive I would move the SSD back to the internet PC.

I assume that the blockchain on the SSD would resynch the send and receive transactions.

I could use Electrum Personal Server, but this means running other stuff which I don't understand. Armory is another option, but I'd prefer to stick with core.

Is my approach feasible? Secure? Overkill?


texts: How do I get my spent bitcoin back into my wallet after a mistaken transaction

texts: I sent bitcoin from my wallet to Excash wallet address not knowing it wasn't up to the minimum wage they accept, now I have not been credited to my bank account yet neither do I have my bitcoin back into my wallet, how do i get my bitcoin back into my wallet?


texts: My question is about Bitcoin, Litecoin and Ripple, to which other currencies (crypto-currency and regular) they can be exchanged? Are they exchangeable with any currency or can each one be exchanged with specific currencies?


texts: What was the longest held UTXO ever spent?

texts: What output had the longest period between when it was created and eventually spent?


texts: Is txindex=1 necessary in the latest versions?

texts:
A few months back when I wanted to use getrawtransaction API call on any txid other than my bitcoin core wallet it would return an error. The error was resolved by adding txindex=1 to the conf file and restarting the daemon with -reindex option.
Now while teaching the concepts to a colleague, I was hoping they would search for the solution when they faced a similar error and would update the conf file. However, the API called returned with the transaction details for any txid and there was no bitcoin.conf file created.

Has the implementation changed which I am not aware about?


texts:
I have tried in all the way to do this by using google and other things .but not find something that give me complete idea for doing this . i have created genesis block successfully and coin is working fine now but still i am not able to mine the coin. i have tried by using solo mining using cpuminer and but it giving me errors like downloading blockchain in progress etc,etc,etc. I thing i am trying in wrong way. So please give me some idea its my humble request to all of you.
Any link or reference is appreciable.
Thanks in advance ...


texts: bitcoin core what is it all about does it make my desktop a server

texts: when my bitcoin core finishes synchronizing does it make my desktop to be like blockchain.nfo where people can create wallets. and must i be online always. apart from that does it mean i have all the bitcoin history from 2009 till date on my hard drive .if my hard drive is compromised does it put all the bitcoin core information in my desktop at risk


texts: Where can I get tick by tick historical BTC volume data?

texts:
Related to Where can I get tick by tick historical BTC price data? but I need volume data in association with price for all the time tick by tick

Thanks!


texts: How many bitcoins do bitcoin faucets give away per day on average?

texts:
I just found out about bitcoin faucets. Apparently they give away very small amounts of bitcoins (or satoshis, for that matter) in exchange for performing some minor tasks, like solving CAPTCHAs or rolling dices. How many bitcoins do these faucets give away per day on average? Are there any statistics? How profitable is it compared to bitcoin trading or mining?

Just curious.


texts: How can one embed custom data in block headers?

texts: Some mining pool admins put custom data in block headers, like prayers. How do they do that? Where can I see that data for myself?


texts:
I'm interested in the long-term ecological implications of using cryptocurrencies. kraken states in The Truth About Bitcoin:

For example, according to a report from 2017, Bitcoin consumes around 8.27 terawatt-hours per year, compared to the 132 terawatt-hours per year consumed by the gold mining industry.
Further, the Bitcoin network can use renewable energy, meaning it can be as good for the environment as its source of electricity.

I don't see any reason to doubt that right now, but the comparison is a bit odd given that the legacy financial system is responsible for (let's say) most of financial transactions, and given that only Bitcoin is considered, instead of all cryptocurrencies.
But what if the crypto enthusiast's dream comes true and cryptocurrency will be used for a significant amount financial transactions, say 50%? What is the ecological impact of the crypto endgame? Will it be an ecological improvement over the legacy financial system?
Notes

I find the second point made in the kraken article (mining can be done with renewable energy) a bit sketchy, as this does not take into account (among other things) the hardware arms race that the miners seem to be involved in: As of the writing of this question, GPU prices are rising rapidly due to shortages, and it is virtually impossible to find a good buy on a mid-tier graphics card. So the answer must take into account not only energy consumption, but also the side-effects of mining. (I should add that at this point roughly 40% of mining is done using renewable energy. So a thorough answer should also consider the possibility that for the near future, a significant portion of crypto mining will probably still be done using non-renewable energy.) Edit: This article outlines some other possible side-effects which an answer should consider.

An answer should probably be based on a guess what the proof-of-work/proof-of-stake/proof-of-solvency/etc. ratio will likely be in the future. How much would a change of this ratio affect the ecological impact of cryptocurrency?

There are questions similar to this one, but so old that I would consider them outdated

References to scientific research that makes projections that take the points above into account are also welcome.


texts: Why does the beginning of `git log` for the Bitcoin source on github say 'sirius-m' was the first committer?

texts:
Satoshi Nakamoto is widely spoken of as being the first committer to bitcoin.

Yesterday I ran gource on the bitcoin repo for fun and was surprised to see that the first commits were by 'sirius-m', or Martti Malmi.

Was there a previous repo in another svn tool and did Martti just do the first commit in git?

It really looks like Martti is the initial committer if you look at the git repo on Github...


texts: Custom altcoin won't sync with node and neither will accept a miner connection

texts:
I forked the BlackCoin source, changed the ports, generated the genesis block, merkle, blah blah blah. I set up a node on a DigitalOcean server and compiled my coin daemon there as well as on my local machine. They two coin daemons recognize each other, I put the addnode into the conf file, also put in rpcuser, rpcpassword, and rpcport into each conf file.

My coin-qt program on my local machine recognizes that it has 1 connection to the network, but for some reason will not stop syncing, even though only the genesis block has been created. It still says out of sync. My server daemon is still syncing too.

When I call getwork, they both return values. Here is what is returned:

{
"midstate" : "79f67436791f93f3eadc9926a8578baddfe15eebe894a6a59ba11fdfb889cef3",
"data" : "00000006edc7bd4e9e7c221bfcc052f25c28c6483d77e1c04ddce735d5a04ba000000ff977168febeac231c7109f85dc43cd9461b7763f9057bb3983622ff0986885b7d9539a6a001e0fffff00000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000",
"hash1" : "00000000000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000010000",
"target" : "000000000000000000000000000000000000000000000000000000ffff0f0000"
}

If I try to call minerd and point them either to the local wallet or the node, like so:

./minerd --url=http://127.0.0.1:14632 -u user -p password

or

./minerd --url={My Node IP}:14632 -u username -p mypassword

it gives me an error!

Specifically:

for the local client:

Unrecognized block version: 6
json_rpc_call failed, retry after 30 seconds

and the node:

HTTP request failed; connect() timed out!
json_rpc_call failed, retry after 30 seconds

Any ideas? I am very close and would like to figure this out!

EDIT--
I went into main.h and changed the value of static const int CURRENT_VERSION from 6 to 1. This seems to have fixed the json problem. As far as the server, I simply had forgotten to open the rpc port and not just the port.

However, my client *coin-qt program continually says 'out of sync' and just says 'catching up. downloaded 0 blocks of transaction history. last block was 2 days ago.' That is the genesis block.

Since BlackCoin uses standard scrypt algorithm, I think minerd should be able to mine this coin. It seems to work alright but I get all 'boos' when mining.

This is the output on my laptop:

@crypto:~$ minerd -a scrypt --url=http://{{node ip}}:14632 -u user -p {{somepass}} --coinbase-addr={{address}} [2014-06-13 12:43:11]
[2014-06-13 12:43:11] Binding thread 0 to cpu 0
[2014-06-13 12:43:11] 2 miner threads started, using 'scrypt' algorithm.
[2014-06-13 12:43:11] Binding thread 1 to cpu 1
[2014-06-13 12:43:12] thread 0: 4104 hashes, 4.76 khash/s
[2014-06-13 12:43:12] thread 1: 4104 hashes, 4.52 khash/s
...
[2014-06-13 12:45:58] thread 1: 756 hashes, 4.60 khash/s
[2014-06-13 12:45:58] accepted: 0/1 (0.00%), 9.33 khash/s (booooo)
[2014-06-13 12:46:02] thread 1: 18408 hashes, 4.71 khash/s

I don't understand why it isn't accepting anything. This coin uses scrypt, the same as BlackCoin. Any ideas?


texts: Migrate old Bitcoin Core wallet to Trezor

texts:
I have an old Bitcoin Core wallet, and recently bought a trezor.
I wanted to use it, but I am unsure how to migrate it. While I can access it with my password, I do not know how to find its 12-word recovery seed (If ever there was one).

Do I have such a recovery seed?
Is there any other way I can migrate my wallet to the trezor? (Other than creating a new wallet and transferring funds from the existing one to this new one)
Can a Trezor hold several bitcoin wallets simultaneously? (Suppose I created a new one, and later discovered I can also access the old one through it)


texts: Bitcoin-qt multiple wallets and transferring between?

texts:
I am sharing pool mining with a friend with equal cards. We are splitting what we mine in half. I also have a couple extra cards of my own. I want to have one wallet for our shared stuff and one coming from my private mining stuff. In bitcoin-qt how do I setup a wallet for the group one and a wallet for just me on the same computer?  Do I just copy in and move out wallet.dat files when I want to use one or the other?

Also what if I want to move money from one wallet to the other how would I do that?  Both wallets are on the same computer?

Thanks.


texts:
I am using this library to make a wallet service that runs on a web browser. I use the library and browserify it so its compatible with the rest of my jquery. Now this tells me how to make and sign a transaction. This specifies the parameters used to make a utxo but I don't understand how to get the data for it.

It says

  It can take outputs straight out of bitcoind's getunspent RPC call

My understanding is that the UTXO can be obtained only when running a full node and not from the browser, so my plan is

1) Send amount, receiver and sender public address to the server using browserfiy, bitcore-lib and jquery

2) Server then finds UTXO (how?) and returns the raw transaction to the browser

3) Browser then prompts using to enter his private key, which is used to sign the transaction and sent to the server

4) Server then pushes this onto the blockchain and returns the transaction hash

I am not able to achieve point 2.
Now I understand that a lot of online wallets would have a similar structure but I am unable to achieve this. The blockchain used is Bitcoin, server side language is entirely in nodejs.

Could someone please help me out/ tag relevant links.


texts: Explanation of parameters from bitcoin/src/chainparams.cpp

texts:
Please explain the following parameters in bitcoin chainparams.cpp file

  consensus.powLimit =
  int256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
         consensus.nPowTargetTimespan = 14 * 24 * 60 * 60; // two weeks
         consensus.nPowTargetSpacing = 10 * 60;
         consensus.fPowAllowMinDifficultyBlocks = false;
         consensus.fPowNoRetargeting = false;


texts: How many transactions per second can blake2s algorithm can handle?

texts:
i saw the hash functions speed (miBps) are 947 according to this website: https://blake2.net/

but how many transactions blake2s algorithm can handle? Verge uses the same algorithm right?

more about blake2s
https://eprint.iacr.org/2013/322.pdf


texts: How to ignore balance check to cancel unconfirmed transaction (double spending)

texts:
I need to cancel a transaction that was sent without fee (using Blockchain.info). It is currently "Unconfirmed". The only way I have found is to do a double spend of the whole wallet, specifying a higher transaction fee.

However Multibit and probably bitcoin-qt will not allow me to send more than my "balance". How can I bypass this balance check?

Where can I request a miner to include a raw transaction in a block (against a bounty)?

Thanks for your help!


texts: What is the algorithm for generating a Ripple address from a ecdsa public key?

texts: I know it is some combination of sha256 and ripemd160 that is used on the public key component to obtain the Ripple wallet address, but what is the specific algorithm?


texts: Parameters in UpdateTip - calculation of log2_work

texts:
I looked up log2_work inside main.cpp and I can't follow its calculation by log(chainActive.Tip()->nChainWork.getdouble())/log(2.0).

a) What is -> explicitely indicating? (I'm at basic level of C++)

b) And what is log2_work exactly saying? Does it quantify the effort of calculation?

Related Question: here


texts: Is pruning transaction history implemented in Satoshi's bitcoin client?

texts:
The original bitcoin paper suggests a method to discard old transactions. One should compute the Merkle Tree of the entire transaction history, and store only part of the tree.

However, I didn't notice this method implemented. BuildMerkleTree stores it in memory only, and seems to assume you're holding all transaction history, and the serialization method stores the actual transactions and does not store the Merkle Tree.

Is that implemented? Can you give me a reference to where is it in the code?

If not, is it planned for a specific future release?


texts: How are eth transaction faster than btc?

texts:
If I'm not wrong miners are trying to find nonce that satisfies a rule.

Then why is btc so slow? I want a technical answer.

Can btc ever match eth speed, given no politics?


texts:
The concept of bitcoin days destroyed has been proposed as a measure of bitcoin volume. However, I don't think the bitcoin wiki really explains the idea very well.

What is the purpose or advantage of knowing this statistical value?


texts: I have PC - i7-6700K CPU @ 4.00GHz & graphic: Intel Corporation HD Graphics 530. My Os is Ubuntu. How many Mh/s i could receive for Ethereum? Let's assume the current is free.


texts: How can I find out where I sent my coins just from an address?

texts: I have the address where I sent it to but I can't remember what the company was I send it to c2752e86c773ae6293b1b89687b0400ac5b416d90b556eb7f0e0fe7ea0704bfb


texts: How can one gauge the reliability, customer service, and transparency of bitcoin exchanges?

texts:
There are several exchanges for Bitcoin with a few highly respected ones like Mt.Gox, Bitstamp, bter, bit-e etc. I understand the reason why they require verification of users by supplying their bank information along with government ID and address proof. However, most of these exchanges decide to keep themselves anonymous to an extent. They don't mention the founding/management team on their website. I'm sure it's possible to find out for some by googling. I don't feel comfortable that they want all the information from me without disclosing anything about themselves.

This also raises the question about what level of security practices and audit do they have in place. I have read several stories about hacking of exchanges, stolen databases/wallets, nightmare to withdraw money etc.

Is there a source of information that compares these exchanges in terms of real world incidents, fee structure, and the backing team behind them? Basically looking for a reliability and customer service rating.

Edit : After Mt Gox's supposed failure, this question feels more relevant. I find myself fortunate that I avoided them. Especially since there were news about a large scale customer data loss.


texts: on testnet: 'transaction already in blockchain'.. but it isn't

texts:
At least I don't think so!
I'm trying to create a wallet infrastructure to minimise fees, and so I've been experimenting with raw transactions. I'm quite clueless but fortunately have enough sense to use testnet instead of the real thing :)
I created a simple raw transaction using a perl script that executes rpc commands to bitcoind. I picked a UTXO that had 0.0625 tBTC on it and tried
createrawtransaction, signrawtransaction followed by sendrawtransaction. I ran this a few times over the same utxo with the result:

{"result":null,"error":{"code":-26,"message":"66: insufficient priority"},"id":null}

(I was trying to see how the number of confirmations affected the priority so I did this at intervals)

Then at some point I started getting:
{"result":null,"error":{"code":-27,"message":"transaction already in block chain"},"id":null}

and yet as far as I can see, it is not on the block chain. I checked the receiving address both by rpc (of course it is my address) and using blocktrail.com/tBTC. Nothing on the receiving address, the original utxo is still there and nothing has changed in my wallet. I tried restarting bitcoind and a rescan but without any success.

What has happened? I am assuming it is not possible via raw transactions to fool the network into thinking the transaction has been transmitted when it hasn't - that would be a major flaw I think. Perhaps my copy of the blockchain has become corrupt? Do I need to reindex to purge this? (Reluctant to try this because in my experience it can take a long time.) Any other suggestions for dealing with this?

Thanks for any help!

EDIT

Actually I'd thought the txid would be returned by the network (and thus would be returned on successful submission) but I guess then it is a hash of the info it contains? Anyway, thanks Nick for inadvertently teaching me sthg there :)
So I did decoderawtransaction and I get the following output

$VAR1 = {
   'locktime' => 0,
   'vin' => [{
      'sequence' => 4294967295,
      'vout' => 1,
      'txid' => '5ef8db75b8f3590dda1865f1dc4810b6d4be56775e4af43b6a394dccafe4422f',
      'scriptSig' => {
         'hex' =>   '483045022100f24e41182ae3f1663b2bde4f9ff2d2e6ce66c0379ab8559c143a442460573da602206a28496206d5881bbb4eea9aa761bf07b3af2b8a6ca44b59e40a9b77059b91ad012102a3012dad956be238d9e17cd1b1473cd0c66968d479e3311e320b2c7b02dfa8b5',
         'asm' =>   '3045022100f24e41182ae3f1663b2bde4f9ff2d2e6ce66c0379ab8559c143a442460573da602206a28496206d5881bbb4eea9aa761bf07b3af2b8a6ca44b59e40a9b77059b91ad01 02a3012dad956be238d9e17cd1b1473cd0c66968d479e3311e320b2c7b02dfa8b5'
      }
  }],
  'version' => 1,
  'txid' => '3bc11bfb7778ad806619f8190231cf907302cfc545d7e5116e24a15795646583',
  'vout' => [ {
     'scriptPubKey' => {
         'hex' =>   '76a91468fd391d83c31283c00bc8b481f3eb698e33799c88ac',
         'asm' => 'OP_DUP OP_HASH160 68fd391d83c31283c00bc8b481f3eb698e33799c OP_EQUALVERIFY OP_CHECKSIG',
         'type' => 'pubkeyhash',
         'reqSigs' => 1,
         'addresses' => [
            'mq65vFheh3mXBvApPKbko8TVHaFQxEHxcf'
         ]
      },
      'n' => 0,
      'value' => '0.06257'
   } ]
 };

I guess the txid in question is then

3bc11bfb7778ad806619f8190231cf907302cfc545d7e5116e24a15795646583

? Again, I can't find this on blocktrail.. and I still have the same error?


texts: How can I generate SegWit addresses from a mnemonic using python?

texts:
So, I have written a script that generates BIP39 mnemonics. I now want to generate N native SegWit public keys from this mnemonic.
I have found this, but it generates legacy addresses. It uses the module bip32utils.
def bip39(mnemonic_words):
    mobj = mnemonic.Mnemonic("english")
    seed = mobj.to_seed(mnemonic_words)

    bip32_root_key_obj = bip32utils.BIP32Key.fromEntropy(seed)
    bip32_child_key_obj = bip32_root_key_obj.ChildKey(
        44 + bip32utils.BIP32_HARDEN
    ).ChildKey(
        0 + bip32utils.BIP32_HARDEN
    ).ChildKey(
        0 + bip32utils.BIP32_HARDEN
    ).ChildKey(0).ChildKey(0)

    return {
        'mnemonic_words': mnemonic_words,
        'addr': bip32_child_key_obj.Address(),
        'publickey': binascii.hexlify(bip32_child_key_obj.PublicKey()).decode(),
        'privatekey': bip32_child_key_obj.WalletImportFormat(),
        'coin': 'BTC'
    }

if __name__ == '__main__':
    seed = 'input display smile visa surround learn solar hero vacuum parrot cigar devote'
    pprint.pprint(bip39(seed))

I assume I need bip44utils or something, but it doesn't exists. I have tried looking at bip-utils but I can't work out how to convert my mnemonic to an address.
Does anyone know how I can convert a mnemonic to a SegWit address (in a way that I can change the derivation path to get multiple addresses)?
EDIT (SOLVED):
I found bitcoinlib can do this.
from bitcoinlib.wallets import Wallet

passphrase = 'input display smile visa surround learn solar hero vacuum parrot cigar devote'

w = Wallet.create("Wallet1", witness_type='segwit', keys=passphrase, network='bitcoin')
WalletKeys = (w.get_keys(number_of_keys=10))

for k in WalletKeys:
    print(k.address)

And now it works just as I wanted it to.


texts: Monitor bitcoin transaction confirmation timestamps

texts:
Well, i'm planning on developing a graph that shows bitcoin transaction average confirmation time per hour , but i have no clue where i can get transaction confirmation timestamps.

I'm running bitcoin core node with whole blockchain and sync up to date.

Any ideas ?


texts:
I'm trying to learn how litecoins work (and learn new programming language at same time by writing a crappy little miner).

I'm stuck with getdata. Here http://litecoin.info/wiki/Scrypt
it says that data is 160 characters long. But its not. Its quite a bit longer than that.

So my questions are:

1.) What is nonce and how do I use it?
2.) What is bits?
3.) What are all the 0's after the bits.

EDIT: Ok, I think I have to use just first 160 characters of data and ignore the rest. Correct?


texts: How can I recover from a corrupted blkindex.dat on Ubuntu 12.10?

texts:
I've installed Bitcoin-Qt after a clean WUBI install, and installed Bitcoin-Qt directly. Now it suddenly says "Error loading blkindex.dat".

I assume my blkindex.dat file is corrupted, and I tried reinstalling Bitcoin-Qt with apt but it didn't work. Maybe if I delete the blkindex.dat file it will try to create it again, but I don't know where the installation folder is.

How can I solve this issue?

Extra information (added by other user); the error will likely look like this:

file blkindex.dat has LSN 727/2518588, past end of log at 727/1519938
Commonly caused by moving a database from one database environment
to another without clearing the database LSNs, or by removing all of
the log files from a database environment
__db_meta_setup: /home/user/.bitcoin/blkindex.dat: unexpected file type or format

You should be able to find this in ~/.bitcoin/db.log. This problem occured when interrupting the client suddenly or maybe because two of them opened the database at the same time.


texts: Is there a flag or specific message in a bitcoin pcap to show us our bitcoin transaction is confirmed or not?

texts:
Assume that I send a specific value from a source wallet to a destination wallet and simultaneously capture the input and output traffic with Wireshark.

I can extract output address and it's value from captured traffic, but how i can detect (from packets of traffic) that my transaction confirmed from miners?

In the other words, when i check out the bitcoin traffic, i see that the specific value which i sent(and it's output address), exists in some packets with different IP addresses, which i don't know which one is a miner. is there a flag or specific message sent to me that help me to understand that my transaction is confirmed?


texts: Variables in Coinbase Transaction & Decoding I/O Scripts

texts:
I just have a few questions to help better my understanding of the coinbase transaction.

Example:

01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff4d04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73ffffffff0100f2052a01000000434104678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5fac00000000

From what I know currently, the format of the coinbase transaction typically looks something like this when decoded:

TX Version:         01000000
# of Inputs:        01
Previous TX Hash:   0000000000000000000000000000000000000000000000000000000000000000
Previous Index:     FFFFFFFF
Input Script Len:   4D
Input Script:       04FFFF001D0104455468652054696D65732030332F4A616E2F32303039204368616E63656C6C6F72206F6E206272696E6B206F66207365636F6E64206261696C6F757420666F722062616E6B73
Input Sequence:     FFFFFFFF
# of Outputs:       01
Output Value (Sat): 00F2052A01000000
Output Script Len:  43
Output Script:      4104678AFDB0FE5548271967F1A67130B7105CD6A828E03909A67962E0EA1F61DEB649F6BC3F4CEF38C4F35504E51EC112DE5C384DF7BA0B8D578A4C702B6BF11D5FAC
Lock Time:          00000000

My first question:

What exactly is the "Previous Index" and why is the value of it FFFFFFFF and not 00000000? Since the previous transaction doesn't exist, shouldn't it be 0 just like the previous hash?

Second question:

From my understanding, the input script contains arbitrary data chosen by the miner when constructing the coinbase transaction and can typically be decoded into ASCII.

For example, this example input script (genesis block) decodes into ASCII as:

ÿÿEThe Times 03/Jan/2009 Chancellor on brink of second bailout for banks

Is this correct? And is this also used when the nonce overflows as an 'extraNonce'?

Third question:

What is the input sequence? Why is it always 0xFFFFFFFF when the locktime is 0x00000000?

Final question (I promise):

What data is stored in the output script, and how can it be broken down to be decoded?

Thank you!


texts: Teslacoin sync error - No Suitable Inputs Found

texts:
Not sure this is the right forum for this, but I thought I'd ask out of desperation.

I have the following error when trying to sync my teslacoin wallet.

I managed to sunc about 6 weeks ago, however haven't been able to sync since then. I left it running overnight and get the error "No Suitable Inputs Found". I'm connected to the tesla network (I think, because I have 8 active connections).

My teslacoin version is v3.2.0.0
The QT version it uses is 5.3.2

Hope that's enough information, if there's anything else required, please let me know and excuse my limited knowledge on crypto, still getting my head around it :)

Thanks

Norrinrad


texts: What exactly is generator G in Bitcoin's elliptical curve algorithm?

texts: What exactly is the generator G in elliptical curve math?  It is typically described as a point on the curve.  Is this a tuple of values?  What properties does it have?


texts: Vanitygen: How ot store all generated addresses?

texts:
i want to know it is possible to store all generated addresses into file (or DB).
How it can be?
For example i need to generate 1,000,000,000 addresses, with vanitygen speed about 50M per second.


texts: How can I setup Bitcoin to be anonymous with Tor?

texts:
Bitcoin is billed as many things, among them its anonymity is highly regarded. While it is true that a transaction does not identify a user or wallet, recent news shows that there is the potential for privacy to be partially undermined, by an 'educated guess' method that may identify the IP address of a transaction originator.

How do I setup to use Bitcoin completely anonymously using Tor?


texts: How do I restore a wallet from a backup file in MultiBit HD?

texts: If I have a backup file like mbhd-*.zip.aes how do I restore it using only my password? When I click on Restore Wallet, it only asks for the wallet words, not the file path or password.


texts: Regtest: address is still at zero after sending some bitcoins

texts:
I'm trying to send some btc to an address in Regtest mode:

the address where I want to send is: mjeoXvBnD4DtZumeSJEjNJfLb4RrhpbH1H

$  bitcoin-cli -regtest -rpcuser=bitcoinrpc -rpcpassword=Alice -rpcport=16591 sendtoaddress mjeoXvBnD4DtZumeSJEjNJfLb4RrhpbH1H 5.00
9caca4f88c6bf727f6e8599fc1012867561ff7ef34412ef1fc70457fadf08e0b

I generate a new block:

$  bitcoin-cli -regtest -rpcuser=bitcoinrpc -rpcpassword=Alice -rpcport=16591 generate 1
[
    "5851b3adfd810480e53fbb5dab1ce4967a50f072a5a7abe054f114839ea3501e"
]

Then, I check the amount of btc inside the address:

$  bitcoin-cli -regtest -rpcuser=bitcoinrpc -rpcpassword=Alice -rpcport=16591 getreceivedbyaddress mjeoXvBnD4DtZumeSJEjNJfLb4RrhpbH1H
0.00000000

Nevertheless the transaction is well listed on listtransactions:

$  bitcoin-cli -regtest -rpcuser=bitcoinrpc -rpcpassword=Alice -rpcport=16591 listtransactions
...
    {
        "account" : "",
        "address" : "mjeoXvBnD4DtZumeSJEjNJfLb4RrhpbH1H",
        "category" : "send",
        "amount" : -5.00000000,
        "vout" : 1,
        "fee" : -0.00001860,
        "confirmations" : 1,
        "blockhash" : "5851b3adfd810480e53fbb5dab1ce4967a50f072a5a7abe054f114839ea3501e",
        "blockindex" : 1,
        "blocktime" : 1452096896,
        "txid" : "9caca4f88c6bf727f6e8599fc1012867561ff7ef34412ef1fc70457fadf08e0b",
        "walletconflicts" : [
        ],
        "time" : 1452096887,
        "timereceived" : 1452096887
    },
...

Is there a problem with my address?

I've generated it thanks to pybitcointools , doing:

magickey = '111' # regtest mode

priv = random_key()

addr = privkey_to_address(priv, magickey)

Thanks a lot in advance


texts: Why do we call it a 51% attack instead of a 50% attack?

texts:
From the Bitcoin paper:

p = probability an honest node finds the next block
q = probability the attacker finds the next block
qz = probability the attacker will ever catch up from z blocks behind

qz = 1 if p ≤ q

In other words, when an attacker controls 50% or more the success rate of a double-spend attack is 100%.

Why is it referred to as 51% attack, and not 50% as 50% is also enough?

Am I missing something here?


texts: Adding instead of concatenating hashes in Merkle trees

texts:
Why aren't the hashes combined using a commutative operation such as addition instead of concatenating them? Any possible vulnerabilities or security flaws?
thanks for your time and efforts.


texts: Transaction instantly rejected trying to send from bitcoin-cli

texts:
Trying to send bitcoins with this command:
bitcoin-cli sendfrom accountdos 1HC...kgT 0.03233376 1

I get this error immediately:
The transaction was rejected! This might happen if some of the coins in your wallet were already spent, such as if you used a copy of wallet.dat and coins were spent in the copy but not marked as spent here.

bitcoin-cli getbalance accountdos 1 returns 0.03464875

I haven't imported the wallet anywhere else, and my node is synced.


texts: BitCoin Core Error Message: "Assertion failed!"

texts:
I am experiencing a recurring problem with my BitCoin Core wallet. The main issue here is that I get an error message every so often as the program is updating the transaction blocks.

Please see the jpeg in the link above, this is the exact error message I get when the client is updating.

Details:

I am using BitCoin Core V 12.0
I have tried reindexing using : c:\Program Files\Bitcoin\bitcoin-qt.exe -reindex
I have tried to reinstall the client, then restart my computer, then open and let it update.
I haven't yet tried a RAM test to see if my RAM could be the source of corrupted data
I'm running Windows 7 OS 64-bit, 8Gb DDR3 RAM

I feel its something that can be fixed with a patch, but I could be wrong. If anyone has a solution that I can try myself, that would be most welcome.


texts: Range proof's Confidential Transaction understanding

texts:
I've some doubt about Greg Maxwell Confidential transaction and hope someone can help to make it clear.
A commitment using Elliptic Curve math is:

                                  P=xG + aH

where G,H are public value and x,a are private.

My questions are:

xG is public or private value?
if xG is a public value  why an attacker cannot simply  make a brute force attack trying all possible value of a checking for the equality with the P value?
if xG is a private value the CT paper tell: can be proven to be a commitment to a zero by just signing a hash of the commitment with the commitment as the public or if if you want to prove a=1 make C' = C - 1H
and then sign the hash of C'. How signing C or C' can I prove the value and also how can I verify a sign if I dont know xG?


texts: How can I assure my consumers they are actually paying the correct person? (prevent MITM attacks)

texts:
There are many network level attacks that give someone Man in the Middle ability to replace my Bitcoin address with their own.

Since there is no way to cancel a transaction, and the best practice is to generate a unique address per sender...

How can I assure my consumers they are actually paying the correct person?

I want to avoid the situation where a sender actually sent payment to a spoofer (which can't be canceled), and still have a dynamic address that people can send money to based on the sender.

A similar question is here, but it doesn't focus on the safety and security of communicating the address from the (anonymous) merchant to the (anonymous) recipient.


texts: How does Alice know she is receiving the correct address?

texts: Let's say Alice wants to send Bob some coins. Bob needs to tell Alice where to send them, so he sends his address to Alice. How does Bob send this address so that Alice knows that the address she is receiving is indeed Bob's address and not an Eve's (an eavesdropper) who wants to steal the coins?


texts: BitMinter - At what data rate communication happens between the BitMinter java client and the server?

texts:
Looking for how many KB or MB transferred each way every second or minute, whatever is appropriate.

I am using a Macbook Pro and using GPU mining.


texts: Bitcoin's real-time Buy and Sell price API

texts: What is the API to get Bitcoin's real-time Buy price and sell price on my site? and how can get it from to implement in my website developed in PHP.


texts: Can a created segwit address match a non-segwit vanity address?

texts: For example, if I have the following vanity address: 1abcde.... as my current bitcoin address, is it possible to create the same vanity address for Segwit: 3abcde... ?


texts: verified transaction in a block is verfied by one node?

texts: i want to know whether block is a combination of transaction verified by one node so all the transaction in that block is verified and once node is full node will broadcast it or any node can add transaction in that block?


texts: would universal use of arbitrage bot stabilize the market?

texts: If each bitcoin exchange ran a bitcoin-arbitrage bot (let's say the same one)themselves, would that quickly eliminate the spread, and therefore the opportunity for arbitrage?


texts: As of 2016-June - Which companies are registered with the NYC Bitlicense?

texts: As of today 2016-June - Which companies are registered with the NYC Bitlicense? I heard that only 2 were given these licenses while everyone else is just waiting. Why and how did these few select companies get this license so easily vs everyone being held back?


texts: How to sign bitcoin raw transactions with Python offline

texts:
I have a raw bitcoin transaction created using createrawtransaction
unsigned_tx = "02000000014bcb8bcbf347d2f91a11703afa644a3ba43cd25a1e8cf538732d65aeb54401070000000000cffgffff0137670000000000001970a91436c27d3f6dd809c25cfbf7d2670ab701a5717b0488ac00000000"

The raw transaction was created using multiple inputs and a single output.
Now I am trying to find a way to sign that transaction offline using Python3 and not connecting to a node.
I have been searching through the web with no luck.
Edit 1:
After following the steps in http://www.righto.com/2014/02/bitcoins-hard-way-using-raw-bitcoin.html, I get stuck with this exception:
In [41]: private_key = "3699556636270870316293620289962549511891625341283681895576015487131205320420"

In [42]: ecdsa.SigningKey.from_string(bytes.fromhex(privat_key), curve=ecdsa.SECP256k1)
---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
<ipython-input-42-48390f7d05da> in <module>
----> 1 ecdsa.SigningKey.from_string(bytes.fromhex(private_key), curve=ecdsa.SECP256k1)

~/workspace/virtualenvs/blah-folder/lib/python3.6/site-packages/ecdsa/keys.py in from_string(klass, string, curve, hashfunc)
    147     @classmethod
    148     def from_string(klass, string, curve=NIST192p, hashfunc=sha1):
--> 149         assert len(string) == curve.baselen, (len(string), curve.baselen)
    150         secexp = string_to_number(string)
    151         return klass.from_secret_exponent(secexp, curve, hashfunc)

AssertionError: (38, 32)

Any ideas where I am going wrong?


texts: Creating an OP_CSV transaction with bitcoinjs

texts:
I'm working on a tool for timelocked contract generation. My redeem script looks like so:

OP_HASH160 <revocationHash> OP_EQUAL
OP_IF
    <bobPubKey>
OP_ELSE
    <timeDelay> OP_CHECKSEQUENCEVERIFY OP_DROP
    <alicePubKey>
OP_ENDIF
OP_CHECKSIG

The goal is that Alice can spend the funds after a time delay, while Bob can spend them at any time by proving knowledge of the hash preimage.

Spending through the revocation hash is easy enough. However, I'm having trouble constructing a transaction that spends based on the timelock is proving more difficult. Essentially, my questions are:

What does the <timeDelay> value represent? How can I e.g. lock the funds for 2 blocks?
From what I've read, the sequence number on the spend transaction needs to be set. But what should it be set to?
How do I practically implement this using bitcoinjs-lib or another library?


texts: What are the arguments for and against deprecating transaction priority?

texts:
A recent pull request moves ahead to deprecate the concept of transaction priority by changing the block priority space to zero. This has enraged some users who believe that deprecating transaction priority means that it will no longer be possible to create zero fee transactions.

So what are the arguments for and against deprecating transaction priority?


texts: Securely erase a previously used address from bitcoin-core

texts:
I'd like to completely delete an address from bitcoin-core, in such a way that someone who obtains all the data on my computer could not find out I ever used that address.
Is it enough to delete wallet.dat? Is there a less destructive way?


texts: Is a hypothetical Bitcoin network on Mars guaranteed to fork from the one on Earth?

texts:
Electromagnetic waves take between ~4 and ~24 minutes (mean: ~14 minutes) to travel a one-way trip between Earth and Mars. Suppose I set up a Bitcoin network on Mars. Is it guaranteed to eventually fork from the Bitcoin network on Earth?

I would expect the Bitcoin network on Mars to fork from the one on Earth, because Bitcoin's target inter-block time is 10 minutes, which is less than average time it takes for electromagnetic waves to travel between Earth and Mars. Am I correct?


texts: How does the sender know the receiver's public keys in a m-of-n transaction?

texts:
Assume that Alice is controlling an address that requires multisig to spend bitcoins. Someone wants to send Alice bitcoins and this sender needs to create a scriptPubKey as part of the output paying Alice.
The scriptPubKey in the sender's transaction should look like this:
m pubKey_1, pubkey_2, ...pubKey_m n OP_CHECKMULTISIGVERIFY

How does the sender know the public keys to send funds to Alice? And further more, how does the sender know the value of m? Isn't it more logical that Alice determines what the minimal number of signatures is?
If I understood correctly this output format is not used anymore, but I still want to understand how it worked.


texts: Which daemon is a lightning node running?

texts:
To run a lightning node we can use 3 different daemons :
 - c-lightning
 - eclair
 - LND

Is there a way to understand which daemon is a specific peer running?