texts: Why aren't miners filling up Bitcoin Cash blocks?

texts:
I see that there are over 100K transactions in the mempool, but most blocks have only a few hundred of transactions.
Can anyone shed some light on this?

The blocks can be seen here: http://blockdozer.com/insight/blocks

Clarifications:

I'm running Bitcoin ABC.
getmempoolinfo returns "size": 101223
getinfo returns "version": 140400


texts: Getting Bitcoin address from Android Bitcoin wallets

texts:
In the android app that I am developing, I need to send a request to check if other Bitcoin apps exist on the user’s phone, and if that is the case, I need to get the user’s Bitcoin address from the wallet.
Is there any type of API/URI specified for this? Or how else can I do that?


texts: Are fees required for distribution when using NXT/Ardor Monetary System when distributing via one of the mining protocols?

texts: The monetary system in NXT / Ardor lets users create their own coin, but also gives the ability to distribute these coins via mining for it using one of the protocols (scrypt/keecka/etc...). When mining for these coins, who pays the network to send these monetary system coins to these users? Are there any fees involved? And when a user successfully mines a coin, do they have to have the native currency in order to send it out?


texts: Why does the first bitcoin client only supported windows

texts:
Starting from version 0.1.0 up to 0.1.5 the bitcoin software could be run only on only Windows 2000 / Windows NT and Windows XP
Was there a technical reason from Satoshi for this choice of operating system, or maybe he wanted his client to be run on the maximum amount of computer, or maybe he had more knowledge of windows ? Linux seem more fit for open source and "Cypherpunk" that windows.


texts: Would bitcoin be destroyed if a wealthy organization obtained a CPU majority for a sustained period?

texts:
Inspired by this question ("Could bitcoin be destroyed by an entity cornering the market?") and the top comment on this answer to this question ("How much would it cost to execute a 51% attack?").

The United States government hates currencies competing with its own, so it may at some point have great motivation to destroy bitcoin.

Answers to the first question show that the government couldn't destroy bitcoin by cornering the market. Answers to the second question show that it would be very expensive for an individual to sustain a 51% attack.

However, the top comment on the referenced answer reads:

  A related point is: why bother mounting such an attack? If you were
  indeed successful and started building your own block chain, then
  confidence in Bitcoin would plummet and investors would sell out their
  positions (assuming their positions could be sold out). The price
  would drop through the floor and the value of your exploit would be
  reduced to nothing.

Given the upvotes on this comment, many appear to agree that a sustained 51% would plummet bitcoin values. This would lead to extreme distrust, and possible collapse, of the system.

But $16.35M + $84k / day is likely spare change for some branches of the U.S. government. If the U.S. sustained a 51% attack almost indefinitely, would this destroy bitcoin? For them, the value of their exploit would hardly "be reduced to nothing", instead it could possibly save their inflationary currency.

One might even say the 51% attack investment would pay itself off with the amount of inflationary income they could generate given the downfall of bitcoin.

This same scenario may apply to any wealthy organization. One could bet on bitcoin falling and then apply this attack for profit. The IMF or a different government could have reason to attack Bitcoin.


texts: What are the parts of and how is a raw coin generation transaction made?

texts:
Referencing: https://blockchain.info/tx/9b0fc92260312ce44e74ef369f5c66bbb85848f2eddd5a7a1cde251e54ccfdd5

With raw data:

  01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0704ffff001d010bffffffff0100f2052a010000004341047211a824f55b505228e4c3d5194c1fcfaa15a456abdf37f9b9d97a4040afc073dee6c89064984f03385237d92167c13e236446b417ab79a0fcae412ae3316b77ac00000000

This appears to differ greatly from a regular transaction and appears to have different parts.  What are those parts broken up and how does one acquire them?  Which part is hashed? etc..


texts: Does a transaction in Bitcoin Mempool reach many miners during mining or only a single miner?

texts:
I'm trying to understand the logic around the Mempool. What I understand is a miner will pick transactions based on an incentive given by the sender, i.e. a fee, so that the higher fee, the faster transaction will get confirmed.

But, What if the transaction get picked by a single miner regardless of fee and that miner is very unlucky miner that somehow it never win the block hashing lottery. Is that possible?

My question is:

Is only a single transaction picked by a single miner and the miner hashes the transaction with other transaction, then guessing the nonce, if it wins, then it includes in the block, else return to the Mempool?

Or,

Is only a single transaction picked by multiple miners and all those miners hash the transaction with other transactions, the guessing the nonce and the miner who wins the lottery included it in the block?


texts: Can I generate multisig addresses directly in the coldcard?

texts:
According to coldcard's multisig video tutorial: https://www.youtube.com/watch?v=OMpZ5heLsRg I need to export the 3 xpubs and then create a multisig wallet in each coldcard using these 3 xpubs. Then it exports a list of addresses that can be plugged into Electrum.
However, I don't wanna trust seeing this list on the computer. Can I see these addresses on the coldcard itself?
Like, generate/visualize one address at the coldcard and then compare it with the electrum one just to be sure I'm sending to my wallet?


texts: How to set up Lightning Network conf file. RPC user / password? and zmqpubraw?

texts:
In my lnd.conf file I have the following settings:

debuglevel=info
listen=192.168.100.134
externalip=186.4.235.84
alias=MyNodeAlias
color=#000000
maxpendingchannels=5
bitcoin.mainnet=1
bitcoin.active=1
bitcoin.node=bitcoind
bitcoind.rpcuser=bitcoind_rpc_user_string
bitcoind.rpcpass=bitcoind_rpc_password_string
bitcoind.zmqpubrawblock=tcp://127.0.0.1:18501
bitcoind.zmqpubrawtx=tcp://127.0.0.1:18502

What is rpcuser and rpcpass? which values should I use? Also, what is zmqpubrawblock and zmqpubrawtx?


texts:
I'm wondering if anyone knows a formula for how to calculate the mining difficulty based on the current hash rate. For an example, if the BTC network would reach 20 million TH/s.
Thank You!


texts: How do i get my Bitcoin out off my Offline wallet Bitcoin QT to an online wallet?

texts: I have payed a test transaction, but it's never confirmed, allready weeks ago. I don't dear to make a bigger transaction, because maybe that will be in the air also


texts: Create a transaction from a wallet coins (UTXOs) with the bcoin library

texts:
I have a multisig setup where the signing is done through external HSM's.
I am using Bcoin and its wallet to receive funds.
What I am trying to do is to create a transaction and sign it with the HSMs.
There are 2 approaches:

Manually create the transaction using MTX.
Use the wallet to create the transaction.

Method #1 solves my problem. The code is even shown here.
However, this method has a big drawback. It requires that I create the Coins. That means, I need to manually create the VOuts and VIns. Meaning that I need to get my UTXO set and choose the ones I need for the transaction. This is very tedious and error prone.

Method #2 solves this issue. When using the wallet, createTx() will create the transaction for you, choosing the VOuts and VIns from the UTXO set for that wallet. However, the problem with this approach is that createTX() signs the transaction. I do not want this as the signing needs to be done by other sources.

So, is there a way for me to get the raw transaction from a wallet without it signing?
MTX has the method toRaw() which gives the raw transaction. Is there any way I can get the wallet to create the transaction, or at least create the VOut/Vin sets?

Thank you.


texts: Get private-keys from wallet using bitcoinj

texts:
I'm using bitcoinj for transferring bitcoin.

Now I want to export private key of my wallet.

So how can I get the private key from bitcoinj?


texts: Where is Double hashing performed in Bitcoin?

texts: where in the Bitcoin Protocol is SHA256(SHA256(x)) performed and why?


texts: Stores that accept bitcoins & Alternatives to Bitmit?

texts:
Are there stores that accept bitcoins?
In particular, are there alternatives to the ebay-like website Bitmit?
Bitmit has shut down, and I am looking for an alternative.


texts: What is the correct algorithm to calculate worker & pool hashrate

texts:
I need to display the pool and worker hashrates on my website.
The pool uses PSQL.


texts: Can I connect 2 different PSU's to 1 GPU?

texts:
I have 2 PSU's 850W and 750W 1 motherboard and 4 cards 280x GPU's.
I would like to connect 2 of the GPU's to a second PSU.
So it means 2 cards are powered by PSU A. and 2 by PSU A via the motherboard and PSU B via the 8 and 6 pin connectors.

Will that be OK? Because I heard that you shouldn't connect a GPU to 2 seperate PSU's.

Do I have to buy powered raisers for the 2 GPU's?


texts: Very hard to sync Core Client from scratch

texts:
Recently I started running a Core 15.1 node with the blockchain on an external hard drive, and found it very hard to fully sync the blockchain.
The problem I keep running into is that (in about 90% of my attempts) the sync does not complete. A DB corruption occurs at some point (usually pretty late in the game, maybe 36 hours into it).

I did some digging in forums and saw that I am not the first user to notice this problem. Peter Wuille mentioned that he does a full sync on like a weekly basis and it always works, and he thus suspects that these type of issues are due to sub optimal hardware.

That seemed very reasonable at first because my initial attempt was done using a pretty old 400gig pocket hard drive. So I switched hard drives.
By now, about 2 months later, I have tried to sync the blockchain from scratch about 20 or 30 times and only twice managed to complete the process.
I did that on 4 different types of hard drives, including a brand new 1T Western Digital.

One may say that all 4 hard drives I used are "suboptimal", but I would object to that because

After the sync does complete, the node runs just fine.
I think it is
desirable to be able to run a full node on a raspberry pi with a
pocket size hard drive (note that I run the node on a raspberry pi
but use my linux desktop to do the initial sync)

Now the issue I have here is not so much the crash during sync, but the fact that when I restart the client after the crash the only option is to basically start from scratch (If I understand correctly, the client is not necessarily downloading everything from scratch but that is not my point) and sync again from Genesis.
Ideally I would like the client to keep synching from the point it successfully got to and not re sync from scratch on such errors.

I am wondering if this resync from scratch on error is necessary. I assume that corruption occurs in one (or more) of the files in the blocks or chainstate directories. If that is so then why sync from Genesis? Is it not possible to, say, delete all files post the corrupted file and sync from there?

If there is no fundamental reason for this behaviour, I would also appreciate a pointer to the relevant code in the client.

Thanks!!


texts: Bitcoin, detecting deposits to the node.js server (code review)

texts:
I'm trying to detect deposits that user will made. I explained it with comment lines in below.

Can you are there any flaw in it?

var _ = require('underscore')

var check = function(client, site) {
    // check last 10 transactions
    bitcoin_client.cmd('listtransactions', '*', 10, function(e, transactions) {

            if (!transactions) return;
            var TRANSACTION = transactions.transactions;

            for (var i = 0; i < TRANSACTION.length; i++) {
                depositDetector(i)()
            };

            function depositDetector(i) {
                return function() {
                    //check if it's received
                    if (TRANSACTION[i].category == "receive" && TRANSACTION[i].amount >= 0.00000100) {

                        var txid = TRANSACTION[i].txid
                        var address = TRANSACTION[i].address
                        var amount = TRANSACTION[i].amount
                        var confs = TRANSACTION[i].confirmations

                        // find it in deposits database

                        deposit.find({
                            'txid': txid
                        }).exec(function(e, _deposit) {
                                // if there is deposit with that txid's
                                //save their confirmations
                                if (_deposit.length > 0) {
                                    _.each(_deposit, function(a) {
                                        a.confs = confs;
                                        a.save() //confirmations updated
                                    })

                                } else { // the txid is new, find user with it's address
                                    //and update user with that transaction amount.

                                    user.findOneAndUpdate({
                                        'btc_address': address
                                    }, {
                                        $inc: {
                                            'btc_balance': amount
                                        }
                                    }).exec(function(e, _user) {

                                            // !e && save deposit to database / finished

                                        }
                                    })

                            }
                        })

                }
            }
        }
    })

}


texts: How a thin node ensures the validity of blockchain?

texts: How a thin node in network verify the validity of the blockchain tree? I think the node must wait for a time period to get the same valid block from some of its peers.


texts: How can I run bitcoind on test and production networks, at the same time, on the same computer?

texts:
Bitcoin and Bitcoind will send an error if it is launched multiple times.  I'm assuming this is because they share the same database and wallet.

Is it possible to run two instances of Bitcoin QT / bitcoind with one listening on Production and the other on Test? (on the same computer)

Is this advisable or not advisable?


texts: Using bitcoinj to discover peers and download the block chain

texts:
I'm sorry everyone, I have looked and stared at the API and I'm coming up with nothing.

I've got a public static void main (naturally), but have no idea how to:

Connect to the network
Download the block chain
Navigate through it.

The purpose of this is to keep the block chain as a record of transactions and perform reporting on my own transactions. I don't have my wallet on the same machine.

Unfortunately for me, my ability to read the api is still underdeveloped, and the various pages I've seen don't really go step by dummy step.

Most important of the above steps is, how to get the block chain...


texts:
When I try to compile bitcoind on a Ubuntu 10.04 machine I do:

make -f makefile.unix

but get errors such as:

In file included from db.cpp:6:
db.h:14:20: warning: db_cxx.h: No such file or directory
In file included from db.cpp:6:
db.h:42: error: 'DbEnv' does not name a type

I wonder what could be the error. In mac os x, I could compile it wothout problem.


texts:
Possible Duplicate:
  Bitcoin client won’t connect to the network

I'm using an iMac with OSX 10.8. Bitcoin-Qt which never seems to sync. I have withdrawn coins from Mt.Gox to an address generated by Bitcoin-Qt. While the transaction has registered with Mt.Gox, there is nothing in my wallet. Do I just leave it open until it syncs, start agin or what?


texts:
It seems that an idea to store all information inside a blockchain would lead to its bloating.

There are about 250MM of domains in the web, namecoin allows to store 1Kb of data per record, it leads to 250Gb of data to store in the blockchain, but namecoin is far more general key/value storage than DNS, so the real size of blockchain is expected to be larger.

Am I right? What is the strategy to avoid or to deal with this bloating?


texts: Creating own altcoin, error loading block database - Have Merkel and Genesis hash

texts:
I am creating my own altcoin on windows.  I've compiled everything, done the first build, found the hash and nonce of the genesis block as well as the merkel root, inserted them into the code, and recompiled.  When I try to run mycoind.exe, the command prompt says "Error loading block database.  Do you want to rebuild the block database now?"

I think it may be because I may have not mined the genesis block, but I'm not sure.

Does anyone out on the forums know what is causing this problem?  I will provide the code to anyone who can help me.

Thanks!


texts: Why don't bitcoin nodes invalidate new blockchains that don't contain all the data of the old blockchain?

texts:
If nodes only accepted new valid blockchains that contained all the data of the old blockchain, then miners will still be able to add blocks to the current blockchain because their blockchain will contain all the data of the old blockchain and the additional data of the new block.
However, double spending will become virtually impossible because if a malicious miner rewrote the blockchain and completed the proof-of-work so they can double-spend, they will be unsuccessful because nodes will only accept blockchains that contain all the data of the old blockchain. A blockchain with a double spend in it will not contain all the data of the old blockchain as it will not contain the double-spenders transaction, so why was this not programmed into the bitcoin protocol?


texts: Why would a Bitcoin miner take less than the full reward?

texts:
In "Mastering Bitcoin", the author notes (source):

  The maximum number of coins mined is the upper limit of possible mining rewards for bitcoin. In practice, a miner may intentionally mine a block taking less than the full reward. Such blocks have already been mined and more may be mined in the future resulting in a lower total issuance of the currency.

I understand that a possible answer is "just because" but I'm wondering if there are other reasons behind such an action.


texts: Is it possible to mine bitcoins faster on CPUs with this strategy?

texts:
This guy on bitcointalk.org suggested a potentially faster method for mining bitcoins using CPUs: https://bitcointalk.org/index.php?topic=265759.0

To quote from the author:

"Rather than computationally solving for SHA256(SHA256(block_header)), the approach is to solve it symbolically.   What I mean by this is, rather than treating the block header input bits as 0 or 1, treat each input bit as an individual symbolic variable (640 in total).   Next, perform the double SHA256, and produce a set of equations that represents each bit in the final hash.  These will obviously be huge, but you can PolynomialReduce after each step of the hashing to reduce the equation size.

The SHA256 output is 32 bytes, so what you end up with is a system of 256 equations, consisting of 640 variables each (which include all the logical operators applied from the double hash.)  For the purposes of mining at difficulty 1, you can discard all but the first 32 equations.

Now to mine using this method:  You have to collapse the equations and simplify.   Take the current, real block_header in question, and fill in actual values in your 32 equations for every bit except for the 32-bit nonce (608 in total.)  Reduce.

Now you have a system of 32 equations, and 32 unknowns.   Set all 32 equations equal to one another, and solve the system of equations.

What you end up with are 3 possible solutions: A nonce that produces 32 "0" bits (what we want), a nonce that produces all "1" bits (discard) or no solution (increment extraNonce.)

Note to make reduction and solving the system of equations simpler, convert the logical operators (xor, or, and) into arithmetic operations and do the reduction and solving in the modulo 2 number ring, for example:

a^b == (a+b)%2
(a | b) == ( (a*b)%2 + a%2 + b%2 );
(a & b) == (a * b) % 2 "

Now, I'm not a math guy, but from what I can gather, this strategy takes up a lot of computing memory. Therefore, my question is - is this strategy theoretically feasible? Can it be as efficient as ASIC mining?


texts: Can the Bitcoin network be used as a timestamping service?

texts: Does the Bitcoin protocol provide means to add some freely definable data to transactions such that a small transaction could actually be used to timestamp arbitrary data?


texts: Accidentally Sent BTC to bitcoin core watch-only wallet with private keys disabled

texts: I think I already know the answer to this, but I just want to make sure as it will result in a loss of funds. I have Specter desktop connected to my bitcoin-core. But because I also sometimes use the core wallet as a hot wallet as well, I accidentally generated the address in the core wallet that is linked to my specter wallet, but the core wallet is a watch-only wallet with the priv keys disabled and then I sent funds to this address and not the address generated by specter or my default core hot wallet. But because this is watch-only my core wallet does not have the priv keys. I am doubtful but is their anyway for the wallet to know it generated this key by enabling priv key.


texts: What is the most cost-effective way to distribute a Bitcoin into 1000 different addresses?

texts: If I have a wallet/address with 1BTC in it, how can I distribute it to 1000 different addresses (1k new addresses with 0.001BTC in each), paying the least amount of transaction fees?  Sending 1000 near-zero-fee transactions and hope that they all get through in an "acceptable" time is an option I guess, but are there any other options?


texts:
Before going to my question, I want to make sure the difference between a full node and a miner. Below definition might be too simple, but it is enough to ask my question.

A full node is to store Blockchain and validate transactions.
There are 10000+ nodes running in Bitcoin network.
A miner is to create a next block.
There are 15+ mining pools create blocks.

Then, here is my question.
UASF is an approach by full nodes to enforce miners(pools?) to trigger the activation of soft forks.
However, if a majority of miners agrees on the activation of soft forks, could they activate it? If so, does it mean that only 15 mining pools could control Bitcoin?


texts: In Blue Wallet 6.0.2 for iOS, pressing on Bump Fee causes an infinite wait. Any idea why?

texts:
Think there might be a bug in Blue Wallet, I imported the said wallet to BlockChain.com iOS App, but the unconfirmed transaction was not even shown there.
In short, how can I CPFP my transaction now?


texts: What files do I need for backing up my wallet?

texts:
Is %APPDATA%\Roaming\Bitcoin\wallet.dat the only file I need to backup my wallet?

I've heard about backing up every ~50-100 transactions is this correct? I thought that with the wallet.dat file, I have my private key, which is all that I need to restore my bitcoins.


texts: Why is OP_SUBSTR disabled? (and OP_LEFT, OP_RIGHT)

texts:
Why are the substring opcodes disabled?
I understand that OP_CAT is disabled because it can blow up the stack easily (in combination with OP_DUP).
But the substring opcodes reduce the stack size.

Context:

  I'd like to use OP_LEFT to implement a proof of work requirement to
  spend a transaction. A substring operation is needed because OP_ADD
  (for salting) and OP_GREATERTHAN only work on 32bit values.


texts: How To Lower The Disk Space Needed For Full Blockchain?

texts:
I'm looking to run bitcoind on a virtual machine.

However the main nets Blockchain size is over 21GB, and growing.

Is there a way to compress this down or lower the amount of disk-space needed for the full Blockchain?


texts: Are there immediate plans to make Bitcoin more accessible to Forex traders?

texts:
Most people trading in foreign currencies are not technical, and will not learn how to operate the "technical jungle" that is Bitcoin.

Are there any known plans to expose Bitcoin to Forex while staying in their comfort zone - e.g. any existing foreign exchanges that plan to support Bitcoin (instead of forcing them to go to websites specializing in Bitcoin?)


texts: What happens when you close a payment channel on tumblebit?

texts:
When you close a payment channel using tumblebit, what happens?
Is the channel that you close always between you and only one other?
Is the channel between you and any number of accounts/addresses?

Thanks


texts: What if the brain wallet is just a memorable private key itself?

texts:
A brain wallet usually applies a hash function on a passphrase to derive the private key. But what if the private key itself is memorable and we just use the private key as the brain wallet?

For example it is very easy to memorize this private key:

Private key: 5JustSomeVeryEasyToRememberBitcoinPrivateKeyWALEmag
Address: 1GtAW7vntpij1q8Mqi3FQw8R1gAd9rnRV4


texts: Checking for confirmations using getrawtransaction and decoderawtransaction

texts:
I am trying to check if a transaction is confirmed or not via RPC commands. At first I tried to use gettransaction, but it doesn't work.

Then I use getrawtransaction and decode it:

{
   "lock_time":0,
   "size":192,
   "inputs":[
      {
         "prev_out":{
            "index":1,
            "hash":"5352d8186b825128a7d4a0df0a8c105da70c81ec763209271566a512fee14cee"
         },
         "script":"483045022100fae0b1dbe08f79a92debde8f3a8e955bcff9ce928b86fb217cfd830af6937386022072386b28a288408bad05426704b55f14a4ad4bf3927ac053facda4478c467eae0121034756f0f954f40ed7dabcaa80c4212a240e4b2c1eee7532bd06cac58c173faf3f"
      }
   ],
   "version":1,
   "vin_sz":1,
   "hash":"931d220f622a9b029cea3e09ca7a9c11f3714c68f9bd272ca97cd915b518050d",
   "vout_sz":1,
   "out":[
      {
         "script_string":"OP_DUP OP_HASH160 0f14a815e42dcdff9c8239a7393b2a9a63a8b68d OP_EQUALVERIFY OP_CHECKSIG",
         "address":"12Njt85fc9Kr7s8tr3Eug4tvkZQUhcGXfz",
         "value":100000000,
         "script":"76a9140f14a815e42dcdff9c8239a7393b2a9a63a8b68d88ac"
      }
   ]
}

And I got the above result. But I don't understand what is written, how can I know if it has been confirmed without relying on Blockexplorer?

Thanks


texts: How does Electrum compute seed byte just before BIP-32?

texts:
As a newbie in Bitcoin and programming it, I am trying to generate BTC addresses from mnemonic. So I read about the BIPs, and found codes in Github that implement those.
I found out that Electrum doesn't implement BIP-39 (by default if I have not mistaken), because mnemonics that are invalid in BIP-39 are accepted by Electrum!
So my question is: How does Electrum do its own "From mnemonic to seed" section (atleast for standard wallet)? This "seed byte" is the one to be used in BIP-32 for generating keys, if I have not mistaken.
I tried the following Python psuedocode (from "Electrum Seed Version System"):
hmac = hmac.digest(b"Seed version", b"...(12 word mnemonic)...", hashlib.sha512)
bip32_thing = Bip32(secret = hmac[:32], chain = hmac[32:]) # default: Bip32 main net version (idk what this means)

But my generated master public key and Electrum's doesn't match (most likely I misunderstood the "Seed Version System" altogether). Thanks for responding!
In case it helps: I am using bip-utils in Python.


texts: According to this article Instant Transaction Fraud: An Explanation, SatoshiDice required all incoming transactions to include fees.  How do they do that?  I assume that they check the "fee" data from the gettransaction() call to the Bitcoin API.  But what happens if the user does not include a fee?  Does SatoshiDice reject the bet and send the bitcoins back?


texts: Bitcoin address with money need help getting it?

texts: I have money in a bitcoin address how do I get the money out of it? I am new to bitcoin any help is helpful.


texts:
I had to remove Bitcoin Core and was trying to reinstall it.
Each time I try to open the Bitcoin Core, I get the following message "Error initializing settings: Failed saving settings file: - Error: Unable to open settings file / Volumes / MyBook / settings.json.tmp for writing".
Your help would be much appreciated.
Many thanks,


texts:
How would one go about detecting whether a mining pool is being dishonest by performing merged-mining without sharing the Namecoin income with its miners?

We assume that:

The pool is operating normally, albeit pays out only Bitcoin rewards
It merge-mines while claiming not doing such a thing

How could we find out the pool is in fact merge-mining and what are the tactics the pool can use to make our investigation harder?


texts: Is there a way to predict somehow the required storage for a specific blockchain?

texts:
I'd like to store a blockchain or two in my computer. Blockchains are pretty heavy (I took over 3hs to download GameCredits blockchain, and is one of the smallest blockchains, I guess). My main fear is to not be able to keep using my pc to store the blockchain (e.g. this applies for others like Litecoin).

Is there a way to track current blockchain storage sizes and predict how much space will I need the next one or two years?


texts: channel count differs on my site and 1ML

texts:
I wonder why:
lightning-cli getinfo;listfunds

{
  "id": "035aef5661e1a6e370db60dc0455796800afd5b51fbc12a0a8b34836b15f5d7ef6",
  "alias": "TWronald✅",
  "color": "15c315",
  "num_peers": 41,
  "num_pending_channels": 3,
  "num_active_channels": 38,
  "num_inactive_channels": 0,
  "address": [
    {
      "type": "ipv4",
      "address": "220.133.223.206",
      "port": 9735
    }
  ],
  "binding": [
    {
      "type": "ipv4",
      "address": "0.0.0.0",
      "port": 9735
    }
  ],
  "version": "v0.6.3rc1-118-g0da4054",
  "blockheight": 563691,
  "network": "bitcoin",
  "msatoshi_fees_collected": 82538
}

157278 satoshi available to fund channels
7318449 satoshi owned in channels
19485999 satoshi total channel capacity
---------------
Total funds: 7475727 satoshi
Percentage of total channel capacity owned: 37.5575
---------------
Add command line parameter [B] for BTC, [m] for mBTC, [y] for microBTC, [b] for bits and nothting or anything else for satoshi
by Rene Pickhardt.
Consider a tip: via curl -i -H "Accept: application/json" -d '{"amount":ENTER_AN_INTEGER_AMOUNT_OF_SATOSHIS_INSTEAD_OF_THIS}' http://ln.rene-pickhardt.de/invoice

On 1ML.com:

Capacity
0.19280979 BTC (0.027%)
$751.22
Channel Count
37 (0.132%)
Connected Node Count
37 (1.120%)

Rene, I tried to send you some thanks, but it should be https and even then it didn't work.


texts: What clients support escrow transactions apart from Blockchain's MyWallet?

texts:
By escrow transactions I mean basic 2 of 3 multi-signature transaction like here https://blockchain.info/wallet/escrow

Are there any other bitocoin clients where I can do this?


texts: Why does BIP44 use non-hardened paths at all?

texts:
BIP44 uses hardening/private derivation on most levels:

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

but not on the change and address_index level. First of all, what does hardening achieve and secondly, what would be the disadvantage of always hardening other than having just half of 2³² paths at that level?

As far as I understood, non-hardened paths allow at the presence of just one simple private key, to learn the xpriv key of the address and if that is not hardened, also the next higher xpriv key all the way up to the first hardened path. Is that so and if yes, what advantage would it have, other than providing 2 billion addresses more in that account's external and change path assuming that the overflow into hardened address spaces were allowed?

A little code to see if/what I got right:

    var wallet = HDPrivateKey()
    var hardened = wallet.derive(4, true)
    var nonHardened = hardened.derive(4, false)

    console.log(hardened.publicKey.toAddress().toString())
    // the payee gets this anyway
    console.log(hardened.publicKey.toString())
    // once I spend from my address, I have to reveal this. It's probably secure to
    // re-use the address but better not to.
    console.log(hardened.privateKey.toString())
    // at this point, you can spend funds that are received to above address and
    // only that
    console.log(hardened.xpubkey)
    // you now know all my addresses I could derive from hardened. Do you know any
    // private keys except for the one I explicitly shared a line before?
    console.log(hardened.xprivkey)
    // now you can spend from all the addresses derivable from hardened but learn
    // nothing else about wallet.

    console.log(nonHardened.publicKey.toAddress().toString())
    console.log(nonHardened.publicKey.toString())
    console.log(nonHardened.privateKey.toString())
    console.log(nonHardened.xpubkey)
    // in difference to the hardened case, you would now learn about nonHardened but
    // also (once again) about hardened? What could you actually learn?
    console.log(nonHardened.xprivkey)
    // would this line leak any information that wasn't already leaked in the last
    // block?

The output:

    1c6dKRqvYPiCQx2R3u75pxGfy15g7jfU4
    0342619d3209b6859f4d88e3b1deaa1acee734c94d625b7d59b286b6842c90bd60
    4c461799315979063858208f6c3e8b33f29ceb10c42389690cd0a20427715845
    xpub68GCDysH8nE2Nuodq1ncV4jYiWvajzZyjVr6Pt8N46QAKC3CPxjj8G6AcE7sdvGypzXZFRRHYjRokhTty6LC8MErRifGiJFeTbTBYL9QfTg
    xprv9uGqpULPJQfjARjAizFc7vnpAV66LXr8NGvVbVikVksBSPi3rRRUaTmgkwDii6TFzWWFsch7Qc2v6eM1ZcJAJLv8ybvw7YY4qwLwvfFJoAp

    1NsxMLRhXasbHaskKVQK4qiJpBZgjTs3Aq
    026653baf78fb78cfb9845faa43080dfc452991422edc67f5ba085d02786364670
    afdb89aaf2f02987dfc47cc655fb4e1fb5cdd545af44875b4176805dc8f60852
    xpub69pTp8pV8Fcmkf3HuiWnzGE42MJcMrTtegoZaLApLUSvhugH6YNKgTtVfk2asMNZWKynCpFoCGePbHLfwJqsLtPskSv5cPF6j1FqmdaNCrE
    xprv9vq7QdHbHt4UYAxpogynd8HKUKU7xPk3HTsxmwmCn8uwq7M8Z1458fa1pVZCfWYWUWMG7p7b99NzJnSwZAnQR6EmN4awbcKZrfdrcmXAXqy


texts: Unconfirmed BTC after 48H, 0.000119 Fee!

texts:
My BTC has been unconfirmed for 48 hours now.
I deliberately made a relative big fee of 0.0001119 and still no confirms.
Could anyone here PLEASE help me I'm getting kind of desperate.
Any miner that could push it, I will send him an extra fee.

This is the transaction: https://blockchain.info/nl/tx/f40f229b36f94bfbaa97a9998107c0014a6ad079370566698ec1cb58f2c94cb8

I would REALLY appreciate any help, thanks in advance!!


texts: How to determine right address from address hash

texts:
I'm using private libbitcoin server and libbitcoin explorer.
When I use bx fetxh-transaction, it returns something like:

I'm trying to figure out, how to get right address from address_hash.
When I use bx base58check-encode for input address_hash without version (or -v 0) it returns:

When I use bx base58check-encode -v 5 it returns:

Check by blockexplorer shows the second way is right.
My question is: How to determine base58check-encode version to generate right address?

Thank you.


texts: Is there a fallback plan if bitcoin's underlying cryptography is cracked?

texts:
Lets say someone started making real viable quantum computers that were affordable enough that large companies could buy one. And lets say a quantum algorithm was devised to crack the private keys of bitcoin public keys in days rather than years.

Is there a plan for that possibility? What would happen? Would there be a smooth migration to another system? Would bitcoin be able to update somehow to protect itself from such a breach?


texts: Bitcoin Transaction Fees When Buying and Selling

texts:
After dipping my toes in the water with Bitcoin, turning £ into BTC, I immediately noticed around a 10% loss through transaction fees. This seems high firstly. Is this normal?

Secondly, with the rate of raise for BTC at the moment, this 10% loss has repaid itself after around 24 hours (which in itself is crazy and unsustainable), but this value is currently stored purely in BTC. If I want to turn the BTC into £ again, I'm guessing this is going to result in ANOTHER transaction fee of around 10%.

All in all, meaning that the value of BTC would need to raise by at least 20% purely to cover the transaction fees when converting between £ to BTC to £ again.

Have I understood all of this correctly? And here I was thinking that PayPal had some expensive transaction fees!


texts: How to install the latest bfgminer binaries directly from terminal without 'aptitude' on a raspberry pi 4 8gb running raspbian?

texts:
months ago I found an entry on StackExchange or somewhere else on how to install the latest (!) bfgminer binaries directly from terminal. I can not find the stackexchange post, no matter how deep I search here / on Google.
I do not remember if it was a download directly from luke-jr's website via terminal or from somewhere else. I only remember that it was done via the terminal and it created an executeable shortcut in the /bin/ and/or /usr/bin/ folder.
Visiting the website from luke-jr triggers my anti virus software telling me the website is infected or hosts infected files. So I can't visit it directly sadly.
Months ago I tried it out on my old RPi and it worked just fine. But now that I had to switch to a newer RPi I can not find or remember the correct terminal command for installing bfgminer binaries directly.
More details about why I need the binaries:
Compiling prints out LOTS of errors for me.
Using 'sudo aptitude install bfgminer' needs "aptitude" installed, so I tried to install it and it returned lots of errors, most of the package files where not downloadable (my Internet connection is fine by the way).
Can you help me out with a terminal command that let's me successfully install bfgminer on raspbian?
On my old Pi I managed to install it without aptitude and without compiling it first.
Thanks so far!


texts: Is there a pro vs con chart comparing Bitcoin's Rootstock vs Ethereum Smart Contract system?

texts: Is there a comparison chart where one compares Rootstock to Ethereum? What are the pros/cons of each system?


texts:
I have a small Python program I'm writing to generate BIP32 keys, including child keys. I've gotten to the point where I can correctly generate a master extended key pair, but I'm not able to correctly derive a child private key and chain code. I've copied my code below:
import hmac
import struct
from hashlib import sha512

def CKDprv(chain, data):
  data = data.to_bytes(33, 'big') + struct.pack('>L', 0)
  return hmac.new(chain.to_bytes(32, 'big'), data, sha512).digest()

def split_key(key):
  length = len(key) // 2
  return key[:length], key[length:]

pub = 0x0339a36013301597daef41fbe593a02cc513d0b55527ec2df1050e2e8ff49c85c2
chain = 0x873dff81c02f525623fd1fe5167eac3a55a049de3d314bb42ee227ffed37d508

digest = CKDprv(chain, pub)
new_prv, new_chain = split_key(digest)
print(f'Chain code: {new_chain.hex()}')

I am using some BIP32 test vectors and trying to derive m/0' from m.
I am deriving a child key with index 0, so I am hashing the parent compressed public key appended with the index represented in 4 bytes.
According to the test vectors, the new chain code I should be deriving is:
47fdacbd0f1097043b78c63c20c34ef4ed9a111d980047ad16282c7ae6236141

but the chain code I receive from my function is:
d323f1be5af39a2d2f08f5e8f664633849653dbe329802e9847cfc85f8d7b52a

I've tried variations such as changing endianness, but nothing seems to get me the correct hash. I know I've probably made a small programming error that is throwing me off completely, and I've been staring at this problem with no progress for a few days now. If anyone can point out the flaw in my algorithm I would be greatly appreciated.


texts: Can you register a .com domain with namecoin?

texts: Namecoin is a generic name-value store, so I'm wondering if its possible to register .com domains in namecoin. The answer here seems to suggest you can register any domain you want How do I register a .bit domain name with Namecoin?


texts: Nicehash autoselected algorithm with very high difficulty

texts:
I'm new at this so please bare with me

I have a couple gtx 750 lying around so I decided to give mining a try.

I used nicehash, according to the site "NiceHash Miner autoselects the most profitable algorithm for your GPU/CPU".

Nicehash autoselected Cryptonight for me. With 80,000 Diff

While observing the result, I noticed I get "yes!" / "yay!" only every after 5-10.

I tried to used other algorithms such as NeoScrypt and it gives "yes!" / "yay!" every 2 mins.

BTW neoscrypt only has 32-64 diff

So my question is which algorithm should I try?


texts: How do Open Source Blockchain companies Stay Competitive?

texts:
I understand the importance of having secure code and your customers trusting your brand. What I do not understand is how do open source blockchain companies like Wallets stay competitive when their competitors can fork their code? Also, is this standard different for closed source exchanges because they do not show source code, however some of them are not regulated.

If I was not clear, I am confused about the whole concept of "Open Sourcing" everything and building a competitive business.


texts: why is the blockchain necessary if bitcoins utilize cryptography

texts:
Mainly I am proposing the idea below because I feel that the blockchain is overkill, but I assume I must be missing something. So if someone could pick out the flaw below, I would greatly appreciate it.

Suppose there is an alternative architecture:

Every user holds a complete ledger, not of all historical transactions, but the current balance of every other user. To send a coin, I would simply send out a message to every node saying who the money is going to and how much. Then using my address (public key), all other nodes can determine if the message actually came from me, and if so alter their copy of the ledger. As a fail safe against double spending, before this alteration takes place, every node would then query other nodes and see if if the majority have received the same message. If two transactions are present, it would enact the earliest timestamped trade (or whoever the majority thinks is first), then accept or reject the later based on balance.


texts: Why pose limit on update ratio of network difficulty

texts:
The Developer Guide on Bitcoin.org says:

If it took fewer than two weeks to generate the 2,016 blocks, the expected difficulty value is increased proportionally (by as much as 300%) so that the next 2,016 blocks should take exactly two weeks to generate if hashes are checked at the same rate.
If it took more than two weeks to generate the blocks, the expected difficulty value is decreased proportionally (by as much as 75%) for the same reason.

Why there is such limit on increase or decrease ratio? Updating difficulty every 2 weeks is not enough to cover abrupt changes?


texts: Storing private key in apps and softwares that are local

texts:
Im new to butcoin. I installed an app in my phone called Bread. And another in my computer called Electrum.

Both of them generated a seed(12 words) for me and it seems that seeed is my private key in the bitcoin network.

My question is: these softwares has my private key and i dont know if they stored it in remote servers. This means someone other has my private key and can access my money? This is a safe way in bitcoin culture? They are really local?

I want to use safest way to work with bitcoin and i dont want store my info in any website or app that can access my account, delete my account or any other intervention.

For safest way should i have my own copy of public ledger in a personal server? What is the safest way?


texts: What software can I use to calculate my private key from a seed (e.g. Trezor or Ledger)?

texts:
I want to make sure I can use my seed from Trezor or Ledger (or others) in a backup process without using an actual Trezor or Ledger to do it.
I have to find out my private key. I probably also need to calculate the addresses I used for receiving bitcoin.
How can I do this?


texts: I was under the impression that BCH did not fork untill 2017.  How was i making transactions in 2011?


texts: creating a hash that starts wtih 9 zeros

texts:
I am working on a school problem and want to generate a hash starting with 9 zeros, it is assumed to be the first block with only your name and the previous hash is 64 zeros.

Can anybody help me or show me how to mine/create a 9 zero hash?


texts:
I saw some addresses in blockchain that the format look "too pretty" to be valid:
- 1fuLL1xxxx1power1xxxxxxxxxxzatvCK
- 1xxxxxxxxxxxxxxxxxxxxxxxxxy1kmdGr

I assume these addresses are actually valid ones, but must never and will never get the private keys from which they are generated (i.e. No one can get the coins on these addresses). Am I right?
If I'm correct, why this guys even send (very little) coins to these "invalid addresses"? For Ad purpose? For fun?


texts: have can i retrive my bcc (bitcoin cash) from bitcoin address?

texts: bittrex says i set bitcoin cash (bcc) to a bitcoin address ..i had made numerous trans actions before using bcc bitcoin cash ,,as i was transfereing i saw the screen change and so did the deposit address to the bitcoin address ..when i contacted bittrex they said it was my fault and said they couldnt do anything and said it was a matter to go to cross chain recovery ...i cant find anything to contact them ..can any help


texts: What was the design decision behind that the coinbase field can have arbitrary data?

texts:
From what I learned, the coinbase field in the block reward transaction can carry any data (As long as smaller than 100b).

Why that actually? Was it easier to implement in the beginning? I would just have defined that the coinbase transaction may have no input. I know it is useful now to carry more information (see BIP34). I'm just not sure what was Satoshi's intention here, although he included himself the famous

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

Further it seems that this is missing in the transaction db and is unspendable, but I may confuse things here.


texts: Ripple Singapore states -34.86 XAU balance, but RippleCharts shows 51.9 (September 2014). How come and what does it mean?

texts:
As of September 6, 2014, Ripple Singapore's (RS's) IRBA page states -34.86 XAU balance and 40 XAU in reserves. Ripple Charts (Capitalization, XAU) shows about 51.9 at this time. Why the difference? (Or does Ripple Charts' Capitalization mean something else?)

I imagine this might come from rippling, though don't know exactly how. I'd still imagine that someone's (eg. RS's) new IOU's can only be issued when they explicitly send the currency to someone else; rippling should only swap different peoples IOU's and not create new ones, right?

Does the difference in balances mean that RS, in addition to bullion in their safes, also holds other peoples XAU IOU's to cover for the difference?


texts: does extended public key derivation go both directions

texts:
I understand that unhardened extended public child keys may be derived from any unhardened extended public key without access to any private keys.

Is the reverse also true -- can a parent extended public key be derived from a child extended public key?


texts:
Bitcoin on-chain transactions are not best option for payments because of fees and there are no confidential transactions on-chain so most of the darknet markets only use Bitcoin for multisig and some don't use Bitcoin anymore. If privacy and payments will never be possible on-chain, are there any efforts or projects related to darknet markets that use LN?
This thread on dread http://dreadytofatroptsdj6io7l3xptbet6onoyno2yv7jicoxknyazubrad.onion/post/a069e66ecbc428fafe0b/ is about BTC, LTC and XMR
There is a hackathon and bounty for developing XMR multisig solution http://dreadytofatroptsdj6io7l3xptbet6onoyno2yv7jicoxknyazubrad.onion/post/a6af0c08fb92560e44de


texts: I sent a Bitcoin transaction to myself using Bitcoin Core and it is not broadcast?

texts:
I am not asking why the transaction is not confirmed, I am asking why it does not show as being broadcast even though it is in the log.

I sent a Bitcoin transaction to myself some time ago using Bitcoin Core, and it just says it is in the mempool after 55 days - I just noticed. Usually, it says broadcast through x nodes. The balance is, of course, showing in my wallet.

Status: 0/unconfirmed, in memory pool
Date: 1/12/17 20:48
Total debit: -0.00004551 BTC
Total credit: 0.00004551 BTC
Transaction fee: -0.00001001 BTC
Net amount: -0.00001001 BTC
Transaction ID: 766dd7ea920a7f40579ee805e649a2fc886e89e9b514f653837b8ab219825af9
Transaction total size: 225 bytes
Output index: 0

I know that the fee might seem a bit low but I did use the fee recommendations, and another transaction with the same fee sent elsewhere at the same time confirmed some time ago.

In my debug.log this time after restarting the node I see:
AddToWallet 766dd7ea920a7f40579ee805e649a2fc886e89e9b514f653837b8ab219825af9

Previously I used to see a debug.log message for rebroadcasting transaction after node restart, which I assume now was this one even though there is no broadcast count, but I cannot see that message yet this node restart. EDIT: log message took a while and looks like this:
2018-01-24 10:51:10 Relaying wtx 766dd7ea920a7f40579ee805e649a2fc886e89e9b514f653837b8ab219825af9
2018-01-24 10:51:10 ResendWalletTransactions: rebroadcast 1 unconfirmed transactions

What needs to be done to resolve this?


texts:
i have run through this tutorial but when i run:

c:\ltcminer\minerd.exe -a scrypt -r 1 -t 4 -s 6 -o http://127.0.0.1:9332 -O pete345234.2:1

i get errors:

json_rpc_call failed, retry after 30 seconds

do i need to use the litecoinpool.org url instead of 127.0.0.1? also does the password matter for minerd.exe

i'm a bit stuck...

edit 1

i changed the command to this:

c:\ltcminer\minerd.exe -a scrypt -r 1 -t 4 -s 6 -o us2.litecoinpool.org:9332 -O pete345234.2:1

but still the response is the same error message.


texts:
This Android application for Bitcoin wallet, claims offline payment as a feature. It says,

  When you're offline, you can still pay via Bluetooth.

A payment is concluded only when the transaction is broadcast to the network and confirmations are made for the transaction in a certain block as mined. So, how does one "pay" via Bluetooth?


texts: What value of nMinimumChainWork and powLimit should I choose for my altcoin?

texts:
// The best chain should have at least this much work.
        consensus.nMinimumChainWork = uint256S("0x000000000000000000000000000000000000000000000005c13f99f6d0b1a908");

how to calculate this parameter, i little not understand. It's not block in blockchain, how find this value if altcoin exist end i update sources with exist blockchain end for new blockchain.

consensus.powLimit = uint256S("00000fffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");

end about this value , how it convert to diff xxx for understand what diff is it. example diff 1, 20, 1000 etc...


texts: storing bitcoin's database directory on an external drive?

texts:
I have a new-ish powerful laptop with SSD, limited to 128GB.
It came with a RAID which somehow didn't work for installing linux, so I had to disable the RAID and now I have actually two 64GB disks really.

That's just not enough to run the bitcoin client on it, the arch linux wiki recommends 80GB of disk space, and even ignoring that rather generous amount, it would fill up my disk.

Is it possible to run the client with a local wallet and all that but having the bitcoin DB on an external drive?


texts: Anyone concerned that, by individuals getting rich too fast, crime towards cryptocurrency holders will also increase?

texts:
Given the potential for such a gigantic paradigm shift, something so accessible and so global could displace enormous amounts of value to large groups of people that previously had very little capital. Not everybody may understand the underlaying technology and how to protect their assets making them easy targets for fraud or exploitation. It's everyone's responsibility to protect them selfs but it on the other side there will be equally or smarter people trying to gain access to their entries on the ledger.

I guess anyone has the ability to protect their wealth in the digital network, but I wonder if we will start seeing more cryptocurrency thefts in the more physical violence context (kidnapping to make someone release their private keys, hardware seizures,...).

Anyone thought of how this will have an impact in terms of crime in the coming 5 or 10 years? Is there going to be a lot of money to protect and a lot of incentive to steal it?


texts: I have been paying amounts of bitcoin, with the promise from Howard Jones in Texas that I will get my private key to get the bitcoin, but when it was time to give me the key, communication went quiet, and the WhatsApp number got deactivated. Now the amount in my Blockchain wallet is going down. Have I been scammed?


texts: Is it possible to track physical objects on a blockchain?

texts:
I am currently working on a project for school in which we have to come up with a product. I won't go into the mechanics of my product but essentially what my group has come up with is using tracking devices to track any object through a mobile/desktop application. When looking through tracking technologies, the idea of using blockchain technology to track physical objects came to mind.

However, I am not entirely sure if this is possible so I would like to know if it is and could it work in theory and in practicality? Has this already been done yet?


texts:
Some 5 years ago I stored some Bitcoins on Blockchain.info, I remembered a few days that I still had a tiny amount left which would be worth something today, around 0.20 BTC in total which makes around $9,500+ with the currents Bitcoin value.
I decided to check my wallet which I did not log in for years. For my surprise the wallet address did not exist, and I was redirected to blockchain.com instead of .info
The login had an input to use the wallet ID, which I did. It then emailed me for authentication which I confirmed, it then asked for my second factor authentication which I entered but for my surprise it then asked me for a second password (besides my normal one). I had a second password stored, but that was only used while spending bitcoins, it was a spending password. I entered that, and it said incorrect, then again, and again and again. I tried multiple times with errors, this was already strange since they never asked this before on login, finally for some reason the page was blank and in a surprise, I was finally logged into my account.
But bigger was my surprise when by BTC balance was 0. Instead, I had around $147 something in the account and my balance is now showing as Bitcoin Cash. Bitcoin Cash did not even exist back in 2017, I never received any email from them about any conversion ever, or I would have moved by balance out. In fact, I don't remember receiving any email from them in years about anything.
I contacted their support, 2 days later no reply. No explanation.
Did they just steal my bitcoins, or I'm missing something here? I found another person here on Stack Exchange that asked the same thing. Is blockchain.com a legit company or are they fraudsters stealing people's Bitcoins?


texts: If someone wanted to pretend to be Satoshi by posting a fake signature to defraud people how could they?

texts: If a random fraudster wanted to post a bunch of mysterious ECDSA signatures that the public would believe came from Bitcoin's creator, in order to disrupt the Bitcoin market, extract money from people, or otherwise convince people to listen to them.  How could they do that?


texts: What is the O(n^2) signature hashing problem and how does SegWit solves it?

texts: One of the many benefits of SegWit is that it solves the O(n^2) signature hashing problem. What exactly is the O(n^2) hashing problem and how segregating signatures to separate witness field solve it?


texts: What's the easiest way to create a backup node?

texts:
My node recently had a data corruption and I had to re-sync it which was painful.
Presuming I don't use the node as a wallet, what's the easiest way to have a backup with the fully sync'd blockchain? Is it as simple as copying over the files from one external hard-drive over to the other?


texts: Why is bitcoin-qt not launching?  Using linuxmint-12-lisa

texts:
i'm using LinuxMint-12-lisa and installed bitcoin-qt as described

Installing Bitcoin-Qt on Ubuntu

sudo add-apt-repository ppa:bitcoin/bitcoin

sudo apt-get update

sudo apt-get install bitcoin-qt

bitcoin icon appeared to Application list and available to execute, but nothing happened after start. Please help


texts: Where is the bitcoin wedding transaction?

texts:
There has been some buzz in the news about a wedding that put a statement in the blockchain declaring their message. Here is one source that reported on the news.

Can anyone provide a link to the actual transaction in a block explorer such as blockchain.info?

I'm looking for a link to an actual transaction in a block chain explorer that has the ASCII text in it that was described in the article, or an explanation of why one doesn't exist.


texts: Can someone with 51% computing power earn more than he deserves?

texts:
See also What can an attacker with 51% of hash power do?

This may have been discussed elsewhere, but I'm not sure what the answer is - if someone owns 51% of the hash power, can't he just ignore the rest of the network, and only focus on his chain, thus earning more than 51% of the rewards (100% in fact)? Will he in fact earn 100% of the reward?

Also - is it possible that several attackers working independently could achieve this scenario? If two people have 34% each, won't one of them always out-race the legitimate chain? Of course, they can't both win, but for some period of time, won't the stronger one among them gain more than his fair share of block rewards?


texts: Since we're just trying to produce a specific hash output, couldn't the nonce also include letters or otherwise random bits?


texts:
The mobile application cashapp specifically says I can send bitcoin to any address anywhere in the world for free.
Coinbase also says they can do off the network transactions instantly and for free as long as both parties have a coinbase address...how does this work ? Does a miner check these transactions ?
Where does the concept of average transaction fee come into place ?
https://ycharts.com/indicators/bitcoin_average_transaction_fee


texts: Security implications of removing CHECKSIG in a test

texts:
If I conduct an htlc transaction on testnet that does not include OP_CHECKSIG will it still cost an attacker more than (say) $10 in processing power or storage to subvert my tests?

Details: I'm tinkering with BIP-0199 htlcs, the last step of which is CHECKSIG. Now, bitcoind does not (yet) expose htlc functionality through RPC, so in order to tinker I've had to implement BIP-0199 via RPC requests myself. To date I've implemented everything I need up to the final CHECKSIG. I understand of Pieter Wuille here that I would need to implement the signing logic for CHECKSIG myself, which seems logical. However, I'm not interested in the role of CHECKSIG in a htlc as I believe it indistinguishable from the same opcode in any standard transaction so I propose to skip implementing it while my tinkering remains on testnet.

Obviously an htlc without CHECKSIG is not secure. For my purposes is it secure enough: Logically,
1. While it remains on testnet, a successful attack obtains no more than testnet coins;
2. The testnet coins that could be obtained are limited to the funds committed to the p2sh address;
3. An attacker who somehow knew that a redeemscript did not contain CHECKSIG would still have to brute force a script whose sha256 hash matches that of the redeemscript in order to redeem funds;
4. An attacker who sees the seller's redeemscript has to obtain matches for the digest and public key (perhaps through hash tables) and still has to get his copy of the transaction mined first in order to cheat the seller;
5. An attacker seeing the buyer's transaction 'only' has to match on the public key then get his copy mined first to cheat the buyer;
6. An attacker that's too slow to get mined first could nevertheless succeed by getting the block containing the transaction orphaned.

And so, an attack on an testnet hashed time-locked contract that does not include CHECKSIG will still require either processing power and/or storage space well in excess of $10. Is my reasoning sound, and if not, what have I missed?


texts: What information is available from the blockchains of privacy currencies?

texts:
Some currencies such as Monero and Zcash focus on protecting user privacy as much as possible. What information is available from the blockchains of these currencies?

Number of wallets? Transaction details? Anything else?


texts: Transfer bitcoins from one wallet to another

texts:
We have started building a bitcoin exchange. Now we basically want to create and address that let users keep their bitcoin asset on that address and we will charge minimal fees to them when they withdraw it.

Now I have api key for my blockchain.info account now if we create an address for user let them deposit bitcoin and then transfer the assets to an address given by user, using api url below

http://localhost:3000/merchant/$guid/payment?password=$main_password&second_password=$second_password&to=$address&amount=$amount&from=$from&fee=$fee

Where will the fee be received?

Please suggest


texts: What's the minimum setup to mine a block alone?

texts:
What's the minimum setup that you guys know, that can, today, mine at least 1 block alone, without the use of mining pools?
I know I wouldn't be able to afford it, but just by curiosity...


texts: Mining on Nvidia(i know it's bad, but it's a start)

texts:
So, I have this nvidia geforce fx5200 d256m gpu in an old box, I want to start it out as a no-cost minig rig(laugh all you want, I'm starting base and hoping to spend zero out of the pocket). I wanted to know what the expected hashrate would be, and what kind of settings I should set it up to use with in cgminer.
Remember people, the question is about the card, not my ideas of what I'm doing. Also this is planing to be done in my basement, which is always cold. So airflow/temp isn't an issue either. It's mining litecoins NOT bitcoins.


texts: can somone create guaranteed future transaction?

texts:
How to create a transaction in Bitcoin that can be spend after a certain period (e.g. 1 month) such that:
1. It is guaranteed that the transaction will be valid after 1 month (the account has enough BTC in it).
2. The amount to be withdrawn is not locked for that period.

Lightning network will allow this to happen. However, the amount must be locked, which violates the second condition above..


texts: What is the practical link between the hashing power in the bitcoin network and its security?

texts: Several books claim that as the hashing/computing power increases, the bitcoin network is securer. How can a non-techie sees that from a practical standpoint?


texts: Buy and selling Bitcoin in different currencies

texts:
If I were to purchase one Bitcoin in Australian (AUD) that is in the tens of thousands of dollars as of this moment, would I be able to sell this bitcoin in American (USD), which is in the thousands? Subsequently making profit from the process as the US dollar is worth more than the Australian.

Thanks


texts: Bitcoin Core software on 2 hard drives with one Wallet

texts:
The answer to this may already be out there, I just couldn't find it.

The issue: My SSD has a few problems, I got the nasty "Disc Read Error" on boot up and while trying to sort that out, it occurred to me that my Bitcoin software is installed on that drive.

I did have the common sense to locate my Bitcoin wallet on my storage hard drive, so all that info is safe and I was able to boot off a spare drive that I use as a back up.  It doesn't have the Bitcoin Core software installed though.

The question: Can I install Bitcoin Core software onto my spare drive without any hick-ups and then access my wallet, or will I run into some issues? Will I have to go through the whole huge initial download thing again?

I didn't want to try until I asked, just in case there is something to look out for.

Thank you in advance


texts:
I was wondering if it is possible for me to obtain data about the Lightning network mainnet, particularly the nodes and the edges (channels) in the network. I know that the graph is visualized in explorers such as https://lnmainnet.gaben.win/ and https://graph.lndexplorer.com/. I wish to obtain the data itself so I can reconstruct the graph and run some network simulations for my research. I understand that the standard way is to run a Lightning node yourself and then sync for the network's topology through your node. However, I do not have access to the computational resources and memory to run a full Lightning node.

If anyone knows of a way I can obtain the data without having to run a Lightning node, or has the data and is willing to share it for purely research purposes, it would be of tremendous help.

Thank you!


texts: Bitcoin Cash accidentally sent to Bitcoin segwit address starting with 3. Can I get them back?


texts: Is every bitcoin transaction (eventualy) validated by every miner?

texts:
I can see that my bitcoin transfers becomes real when my exchange detects 2 or more confirmations.

I believe each confirmation is a validation. Am I correct? If so, How many confirmations will have my transaction? As many as miners does exist? If not, how many?


texts: How do I make payment with a wallet by copy & pasting an address?

texts: I purchased bitcoins, I added the wallet, but I do not know how to make a payment? I was told by the website to make a payment by copying and pasting the address? Now what do I do with the address?


texts: Getting "N5boost10filesystem16filesystem_errorE" error when running bitcoin-cli

texts:
Backstory
I'm running Bitcoin Core 0.20.1 on a Raspberry Pi 4 (running Raspberry Pi OS standard).
It's just a standard install of Bitcoin Core, I built from source and installed into /home/pi/.bitcoin (looking back, I should have created the 'bitcoin' user first).
I created a new user 'bitcoin' and mounted an external HDD (under /mnt/bitcoin), now when running bitcoind I specify this location as the datadir. I had initially added this location in the bitcoin.conf file but was getting errors and someone mentioned not to add the datadir in the conf file.
Bitcoind runs just fine and uses the correct datadir when using the following command (whilst logged in a bitcoin user)
bitcoind -daemon -datadir=/mnt/bitcoin

The issue
The issue is when I try to access a bitcoin-cli command.
I'm currently getting the following error when running
bitcoin-cli getblockcount

************************ EXCEPTION: N5boost10filesystem16filesystem_errorE
boost::filesystem::create_directory: File exists: "/home/bitcoin/.bitcoin"
bitcoin in AppInitRPC()

It can definitely access bitcoin-cli, as when I run the command without any parameters, it returns the help screen.
Can someone point me in the right direction to fixing this please?


texts: Why does my freshly installed lightningd not show funds that I transferred to it?

texts: I have a box with Ubuntu, bitcoin: fully indexed, and c-lightning.  I made several new addresses, and put money into one of them.  The money was transferred to it in block 655761.  I see the bech32 address when I run dev-listaddrs, it was sent to the right address.  Why would list funds show no outputs?


texts:
I am getting this error when I type getbalance:

error: {"code":-1,"message":"std::bad_alloc"}

Basically, I type getbalance and wait for about 2 minutes and this error appears finally.

What does it mean?


texts:
Is there a particular reason fees higher than the transaction volume are allowed?

What about imposing this:

Smallest output must be at least 10 times the fee.

Might reduce Spamdice transactions (thinking of losing bets notification).


texts: How do I determine whether an input or output is segwit?

texts:
I'm trying to go through the transactions in a block and determine how many segwit inputs or outputs there are.

I've noticed in getrawtransaction that segwit inputs seem to have a 'txinwitness' field. Is that a good way to classify them?

For outputs I know I can't just look at the 3* address because not all p2sh are segwit. So what's the best way there?

EDIT:
I just found this page about 3* addresses. Difference between a SegWit address and a P2SH address

Am I correct in interpreting this to say that you can't determine whether an output is segwit? Only an input?


texts:
It seems that the most widely used symbol for Bitcoin is a B with two vertical lines through it1. It makes sense, as a single letter with a line or two through it is common for many currencies. Is there a plain text printing for this symbol, or perhaps a font that can insert it into documents and the like? What about a hex code or something for HTML printing? I'm looking for other ways to denote the currency without using an image.

With the symbols found here, it looks like a circle around it might become part of the official symbol as well. Maybe I should ask that separately.


texts: Entropy gathering from already generated bitcoin keys?

texts: Say someone has generated n bitcoins. Now, these are from very good entropy. When regenerating new keys, would it be a good idea to take the keys for entropy improvement? On the one hand, the entropy is already destinated on the other hand, it comes from the best sources? As special case, would talking only parts of it be a better idea?


texts: Can you get the seed phrase of a HD wallet from the private key of one of the wallets?

texts:
Let us say I have a HD wallet. Can I get it’s seed phrase from the private key of one of its wallets?
Also are seed phrases just easy to remember private keys? If so does that mean that from the seed phrase private key you can get a public key? And if this is true if I send cryptos to this public key in which HD wallet is it going to appear in? The first one?


texts: How to recover from a double spending attack?

texts:
I found myself incapable of answering what would happen in this case, so here it is:

A hacker (Mr Hacker) spends UTXO_1 and UTXO_2 in TX_1, depositing the monetary value of all TX_1's outputs into a Service (eg a payment processor).
A legitimate user (Mr Legit) spends UTXO_3 in TX_2. Again, TX_2's outputs targets the same Service
Both TX_1 and TX_2 make it into the same block and get one confirmation by the network.
The Service immediately spends UTXO_1 and UTXO_3 in TX_3 to pay Mr Legit and UTXO_2 in TX_4 to pay Mr Smith.
Mr Hacker then decides to double-spend TX_1 and for that reason he creates TX_5 which "redirects" all outputs to himself. Mr Hacker is a miner so he is able to perform all the hashing work to make the double-spend successful. He is also lucky and the double-spend succeeds.

So the question is:

Have all TXs before TX_5 (TXs: 1,2,3,4) been invalidated or just TX_1, TX_3and TX_4 (TX_3 and TX_4 spent an output previous controlled by TX_1 which was double-spent)?
Mr Legit could see 1 confirmation for TX_2 before the double-spending. What does he see now? What does Mr Smith see in his wallet, before and after the double-spending?
The Service realizes that a double-spending took place and needs to recover from that broken state. What does it have to do to get back to normal operation? Does it have to re-send all the TXs? Does it still have in place the deposits made by TX_2 after the double-spending or does it have to do something to re-claim these outputs?
How can the Service prevent Mr Hacker, who also has plenty of money to spend, from repeating the same process forever just to ruin the Service's smooth operation, rather than (the Service) waiting for more confirmations before sending out the payments?


texts:
I saw a recent article supporting Craig Wright's claim to being Satoshi Nakamoto.  Other articles about him suggest that most of the community believes he's a scammer, and not actually Nakamoto.  The evidence he provided was some signature that apparently proved nothing.  On the other hand, Bitcoin developers challenged him to reveal the private key.  That seems pretty extreme, as it would allow anyone to spend all his BTC, no?
Wouldn't an appropriate demonstration be to announce that you are going to transfer a very precise but token number of BTC to some wallet, say, a charity?  This would preserve everyone's private information, but demonstrate that he has control of Nakamoto's BTC, no?  I assume anyone who is unwilling to make such a demonstration would automatically be assumed to be a fraudster.  What am I missing?


texts: Install 2 Electrum wallets in a same computer

texts:
I have an Electrum Wallet in my computer, and I'd like to transfer my BTC to another Electrum Wallet, with a new seed and new adresses.

Is it possible to have 2 Electrum Wallets in a same computer? If so, how can I install it?


texts: How to determine public keys that were used to generate a multisig address?

texts: How can I verify the public key that I provided was actually used to generate the multisig address I'm funding for say escrow?


texts: Why are a majority of the namecoin sync messages "ConnectInputsHook() not in pending - must be someone elses"

texts:
I'm comparing the run time debug logs of namecoin and bitcoin and noticed that much of namecoin's initial sync processing is dominated by the following command:

ConnectInputsHook() : connecting inputs on bd3dd490663d35b1bb4f196335e84d84148c7f5573acb0f7c993dcfffe6fdf35 which was not in pending - must be someone elses
ConnectInputsHook() : connecting inputs on 93a1fc009d5bda3f2670c3b8a40eebaead3128d83762346106fba6af4bd87b45 which was not in pending - must be someone elses
ConnectInputsHook() : connecting inputs on d654e34b29e1cbd2c14b8437b020b7bf24b0366a39acb0eb7e754581e7100af8 which was not in pending - must be someone else's

... of course the inputs vary, but I'm at block 4300 and I'm getting tons of these "errors".  What causes these messages and is that normal going forward?  (what are the conditions that cause these messages)?


texts: What exactly is a private key and public key in relation to Bitcoin? What are they, how are they used, and how does one find out what their private and public keys are?


texts: How to minimize risk when accepting zero confirmation payments?

texts:
I'm trying to setup a way of accepting Bitcoin payments in real life situations, where waiting for confirmations is typically not an option. I understand this is never 100% risk free (especially with crap like bitundo.com around), I just want to minimize the risk.

I've got a Bitcoin Core wallet with a bunch of unused addresses. I show the customer an address, he sends the money, and now I can do a few things: (all automated, i.e. through some kind of application or script)

Check if the (unconfirmed) transaction appears on my own node / in my wallet
Check if the (unconfirmed) transaction appears on sites using online APIs like blockr.io and blockchain.info
Check if I don't see a similar transaction (from the same input address, but to another output address, i.e. a double spend attempt) on either my node or API sites.

If 1 or 2 are OK and 3 doesn't occur for e.g. five to ten seconds, how (un)certain is the transaction at this point?

I noticed that payment providers like bitpay and coinbase can sort of accept payments immediately, how do they tell legit transactions from double spend attempts?


texts: How to synchronize with the bitcoin blockchain via bitcoinJ

texts:
I'am writing my very first application using bitcoinJ api and I got a bit stuck. Maybe somebody can tell me what I am missing.

My practice app wants to write a sample contract in the bitcoin blockchain, but it seems like, when I try to do so. I get a message from bitcoinJ that says:

  java.lang.IllegalStateException: Cannot call until startup is complete

I think I need somehow to wait for the blockchain to synchronize, so I can send stuff to it right?

This is how my java code looks like:

import org.bitcoinj.core.*;
import org.bitcoinj.kits.WalletAppKit;
import org.bitcoinj.params.RegTestParams;
import org.bitcoinj.script.ScriptBuilder;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class SimpleExample {

    private WalletAppKit bitcoin;
    public  NetworkParameters params = RegTestParams.get();

    public SimpleExample() {
        bitcoin = new WalletAppKit(params, new File("."), "testfile" + "-" + params.getPaymentProtocolId()) {
            @Override
            protected void onSetupCompleted() {
                // Don't make the user wait for confirmations for now, as the intention is they're sending it
                // their own money!
                bitcoin.wallet().allowSpendingUnconfirmedTransactions();
            }

        };
    }

    public void timestamp(File doc) throws IOException, InsufficientMoneyException {
        // Hash it
        Sha256Hash hash = Sha256Hash.of(doc);

        // Create a tx with an OP_RETURN output
        Transaction tx = new Transaction(params);
        tx.addOutput(Coin.ZERO, ScriptBuilder.createOpReturnScript(hash.getBytes()));

        //Check if the Blockchain is synchronized before you do anything!!!!!!

        // Send it to the Bitcoin network
        bitcoin.wallet().sendCoins(Wallet.SendRequest.forTx(tx));

        // Transaction proof
        Proof proof = new Proof();
        proof.setTx(tx.bitcoinSerialize());
        proof.setFilename(doc.getName());

        // Grab the merkle branch when it appears in the block chain
        bitcoin.peerGroup().addEventListener(new AbstractPeerEventListener() {
            @Override
            public void onBlocksDownloaded(Peer peer, Block block, FilteredBlock filteredBlock, int blocksLeft) {
                List<Sha256Hash> hashes = new ArrayList<>();
                PartialMerkleTree tree = filteredBlock.getPartialMerkleTree();
                tree.getTxnHashAndMerkleRoot(hashes);
                if (hashes.contains(tx.getHash())) {
                    proof.setPartialMerkleTree(tree.bitcoinSerialize());
                    proof.setBlockHash(filteredBlock.getHash());
                }
            }
        });

        // Wait for confirmations (3)
        tx.getConfidence().addEventListener((confidence, reason) -> {
            if (confidence.getConfidenceType() != TransactionConfidence.ConfidenceType.BUILDING)
                return;
            proof.depth.set(confidence.getDepthInBlocks());
            if (proof.depth.get() == 3) {
                // Save the proof to disk
                String filename = doc.toString() + ".timestamp";
                try {
                    proof.saveTo(filename);
                    System.out.println("Proof complete - Saved to " + filename);
                } catch (IOException e) {
                    System.err.println(e);
                }
            }
        });
    }
}


texts: How do I register a .bit domain name with Namecoin?

texts:
I have several namecoins and would like to register a name.  That name could either be for TOR, DNS, or any other purpose.

What are the steps needed to spend these coins?


texts: Where are the most realtime (up to date) stats for exchanges like mtgox? For basic stats like exchange rate and volume, what is the best, average, and worst-case reporting delay and what's the URL?


texts: Can I regenerate blkindex.dat from blk0001.dat?

texts:
My copy of blkindex.dat became corrupted, but I still have the whole blk0001.dat file.

Is it possible to reconstruct the blkindex.dat file from the blk0001.dat file or do I have to delete both files and redownload the whole blockchain from scratch?

Edit: Pieter's answer is working for me.  It's taking many hours to run, but at least it isn't using any bandwidth.  I'm wondering, as a related question, whether this bitcoind -loadblock=blk0001.dat.bak technique is a way of being able to get a trusted copy of the blockchain from an untrusted source.  If I download a blk0001.dat from a random website, then import it using this -loadblock command, does that ensure it's correct, and ask the network for anything the download was missing?

While running, the command just said:

SetBestChain: new best=00000000000004411998  height=174305  work=284206530118085534778
SetBestChain: new best=00000000000009a01d64  height=174306  work=284213516218692473063
InvalidChainFound: invalid block=000000000000038181de  height=174307  work=284220502319299411348
InvalidChainFound:  current best=00000000000009a01d64  height=174306  work=284213516218692473063
SetBestChain: new best=00000000000007e352ec  height=174307  work=284220502319299411348
SetBestChain: new best=00000000000006b4b91c  height=174308  work=284227488419906349633

Is that normal, representing an orphaned block?  Or possibly the result of the same disk error that caused the blkindex.dat to become corrupted initially?


texts: Is offline Bitcoin transaction signing safe?

texts:
How can offline transaction signing ever be safe? I'm relativly new to bitcoin and this is one part that I cannot understand.

Lets say I create a transaction at my watching-only wallet. Then I sign it on my offline wallet. That means I just "toggle something"/"add some data that says signed" when I'm signing my transaction at the offline wallet.

Isn't that easily hackable so that everybody can easily sign transactions without knowing the private-key? I mean the watching only wallet has no clue of the private key so there must be some information that is != private-key in the data that comes back from the offline wallet.

Even if I sign it at the online-wallet somebody could just change the sourcecode of the client that he does not need the private-key to sign something.


texts: What is a good analogy (which a layperson would understand) for the process of Bitcoin mining?

texts:
I will be explaining Bitcoin to a non-technical group and I am hoping somebody can provide me with a very basic visual analogy of the crypto-currency mining process.

My half-baked idea, was to somehow describe the mining process as partaking in a complex word search. Hopefully getting my group to visualize a large pool table sized word search (block) and have them imagining searching for a 30 alphanumeric character identifier (wallet). Describing the blockchain as a city sized word-search on top of 21 million pool tables?

Is this a good analogy to use, or is there a better/more applicable one?
Using (and adding to) the best analogy, how can I explain the difference in mining with CPU/GPU/ASIC and why the ASIC hardware is the quickest?


texts: Decoded transaction hex without enough signatures?

texts: Can someone show me the output of decoderawtransaction when the transaction requires multiple signatures, but it hasn't been signed by enough people, and the transaction was created using createrawtransaction?


texts:
I found Block 507570.

There are only 51 transactions in this block but its size is almost maximal, there are 3,964 input adresses with exactly 0.0001 BTC.
The sender paid only 10$ for 61,602 Bytes here for example and there are 19 similar transactions in this block.
Is this an attemp to waste space of the blockchain?


texts: Why don't nodes resume all existing outbound connections at restart?

texts:
The Erebus attack can, according to the authors, be accelerated by causing the victim node to reboot* at opportune moments. This is because the node will pick new outbound peers from a list that's been compromised by the attack.

What's the reason nodes don't frequently store their current outbound peers to disk and reconnect at restart?

* by causing it to crash, which nodes are hardened against as much as possible


texts:
So i have retrieved an old wallet.dat file. When i open it in bitcoin-core i can only see the adress as an watchadress. I went to the console and typed - listunspent and this shows up.
I understand why the bits are unspendable due to the fact that it only shows as a watch-adress. But how is it possible that it says "solvable -false" since i accessed with the wallet? Am i missing something very important here?
"vout": 14,
"address": "-------------------",
"label": "",
"scriptPubKey": "----------------------",
"amount": 0.60790000,
"confirmations": 257190,
"spendable": false,
"solvable": false,
"safe": true


texts:
I'm experimenting with Segwit transactions.

Is it possible to restore redeem script, if I know
1. Address (Segwit)
2. Public key
3. Private key

Thank you.


texts: How do I print unspent transaction outputs of an address using pybitcointools

texts:
I am a beginner looking to write a simple program that takes an input (address) and prints the unspent amount in it.

I copied some code from chapter 4 of Mastering Bitcoin to generate a random keypair, and the last lines Andreas had in the code I copied were:

>     # Generate bitcoin address from public key
>       print "Bitcoin Address (b58check) is:", bitcoin.pubkey_to_address(public_key)
>
>     # Generate compressed bitcoin address from compressed public key
>       print "Compressed Bitcoin Address (b58check) is:", \
>           bitcoin.pubkey_to_address(hex_compressed_public_key)

I added the following bit at the end that prints the UTXO. It is currently printing "[ ]" because there are no UTXOs because I'm generating a new address, but it at least works when I do this and prints something.

>     #Print the UTXO for the given address
>     print bitcoin.unspent(bitcoin.pubkey_to_address(public_key))

However, when I type an address instead of the "(bitcoin.pubkey_to_address(public_key))", like so:

>     print bitcoin.unspent(16jn6k2FJqwrNLDpbZmmmpf4TCW7uM6LED)

It gives me an error ("SyntaxError: invalid syntax) and points to the "D" at the end of the address. I really want to use this specific bit of code to enable me to enter an address and have the UTXOs returned. (Please note, I just found that address on blockchain.info by clicking addresses until one with unspent coins came up! Also I am a complete novice so please go easy on me!)

Thanks in advance


texts: Can I use walletnotify or blocknotify remotely with a NodeJS application?

texts: I'd like to get information from my bitcoin node running on a cloud server to be used to make changes in my NodeJS app running on my computer. So, in the bitcoin.conf file, should I have something like walletnotify=curl http://My.IP.Address:PortAppUses/walletnotify.js?tx=%s? If that's right, what do I write in the walletnotify.js file to simply save the incoming transaction id as a variable?


texts: Fixing "Block not found on disk" rpc error

texts:
I have a full node with txindex enabled that I've been trying to use for an electrum server. However, whether I use ElectrumX or Electrs, I hit the same error on initial indexing of "Block not found on disk". With a bit of digging, I found out this error comes from the getblock rpc call, and the comment in the code for when this error is thrown is as follows:

  Block not found on disk. This could be because we have the block
  header in our index but don't have the block (for example if a
  non-whitelisted node sends us an unrequested long chain of valid
  blocks, we add the headers to our index, but don't accept the
  block).

I'm not sure how I got to this state. This is a node I initially spun up several years ago and reindexed to use txindex earlier this year, I've never had any issues with it for other purposes or any data loss/corruption issues that I can recall. If anyone has a theory/explanation, I'd be interested to hear it.

My question is: Can I fix this error without starting over from scratch? I'd like to avoid even a reindex if possible, although I'm not even sure if that would fix it because as I understand it reindex uses the blocks on disk and apparently I'm missing a block on disk. Is there a way to get only the block or file(s) that I need? I have a friend with a full node who would let me copy files if needed.

I don't know exactly which block is missing yet, although I could probably figure that out with some more digging if it would be helpful.


texts: I have a 12 word passphrase and password from blockchain.info.  Trouble is that I can't remember the email I used.  Is there a way to retrieve the email with these two pieces of information?


texts: What are the downsides of proof of stake?

texts: I am very skeptical about the security of the proof of stake system. Is it really that secure? Are there no disadvantages?


texts: Does submitblock require the wallets private key?

texts: I would like to know if invoking the submitblock RPC is supposed to work if the daemon that handles the RPC does not have the private-keys for to the coinbase output address?


texts: Possible race condition(double spend) on HTLC-Timeout in the lightning network?

texts:
From the offered HTLC Outputs,

# To remote node with revocation key
OP_DUP OP_HASH160 <RIPEMD160(SHA256(revocationpubkey))> OP_EQUAL
OP_IF
    OP_CHECKSIG
OP_ELSE
    <remote_htlcpubkey> OP_SWAP OP_SIZE 32 OP_EQUAL
    OP_NOTIF
        # To local node via HTLC-timeout transaction (timelocked).
        OP_DROP 2 OP_SWAP <local_htlcpubkey> 2 OP_CHECKMULTISIG
    OP_ELSE
        # To remote node with preimage.
        OP_HASH160 <RIPEMD160(payment_hash)> OP_EQUALVERIFY
        OP_CHECKSIG
    OP_ENDIF
OP_ENDIF

With the following conditions,

a locktime is set to be 600900 in the HTLC-Timeout transaction.
the remote node has the payment_secret.
the local node wants to timeout the latest commitment transaction.

From my understanding, to timeout the latest commitment transaction, the local node has to,

broadcast the commitment transaction at blockheight 600900;
immediately broadcast the HTLC-Timeout transaction;
wait a few days to spend the HTLC-Timeout transaction once the specified timelock value has passed.

Meanwhile, the remote node with the payment_secret can spend the commitment transaction too. Will this cause a race condition/double spend in the Bitcoin network? If so, how can it be resolve?


texts: Why doesn't the Bitcoin core team develop official Bitcoin mining software?

texts:
If I am right, the Bitcoin Core just maintains the software necessary to run a full node. Essentially it's the code for the Bitcoin wallet, which just verifies blocks, but doesn't mine. But mining is an important part of the Bitcoin network, and the most widely used software is the unofficial BFG miner written by Luke DashJr.

So why is it that the Bitcoin Core team does not develop an official Bitcoin miner as well? Also I believe the first version of Bitcoin core released by Satoshi was full node software as well? How did mining happen then?


texts: List of crypto currencies built with java?

texts: Is there a list of crypto currencies that was built with Java?


texts: Is it safe to create a Bitcoin account for another party? Is this a scam?

texts: A guy I have been talking to says he is having trouble accessing his account and asked me to make a wallet in blockchain and then wants my login, password, and wallet id so he can use it in another country. I have $0.00 in my wallet. Is this safe to do? I’m trying to figure out if this is a scam and if so how ? I also have no intentions of buying any bitcoin for myself now or in the future


texts: Stop bitcoin-qt from retrying transaction

texts:
I sent some bitcoins, forgot to uncheck "no-fee" checkbox. The transaction started, but never got confirmed. In the blockchain after some time it was "purged". I expected my bitcoins back, however, what I believe is, the client tried to send them again - because the transaction appeared on the blockchain.info just after I turn the client on. And this cycle repeats now.
Is bitcoin-qt really retrying transaction? If so, how can I stop it?


texts: NBitcoin - how to set RBF to true in order to give higher fee for transaction

texts:
I have a few transactions staying unconfirmed - been a few days now.

I suspect the minimum  mining fee was upped - 15 minutes prior I was still doing hundreds of transactions a day at that fee - but now it is not enough.

All documentation indicates this is an easy process - simply use the same TX as you used earlier.

I am now feeling that this is more involved.

I took the unconfirmed TX - and goot its prev_hash.

I loaded the TX of this prev_hash and resubmitted it to BlockCypher - and get the message :

Error sending transaction: Unable to lock an input of transactions xxx, likely already spent by yyy..

It correctly identifies that unconfirmed transaction in yyy placeholder.

Thus it does not want to spend it as its already spent.

Now there is a Readonly RBF property on NBitcoin.Transaction class.

RBF means "Replace by Fee" which is what I want to do - but I can't set it as it is read only.

How do I go about to indicate this is a RBF?


texts: Can one _see_ one's private key in, and _transcribe_ it out of ... a laptop wallet?

texts: Suppose I download bitcoin wallet software, or Armory, and create a new account, on my laptop. Can I see and transcribe the newly-created private key?   Then suppose I receive some Bitcoin into this new wallet-on-laptop. If I transcribe the private key I can see onto durable media, (a paper wallet, coldsteel device, or some other durable material), then I could remove the wallet software from my laptop completely and be left with a hard wallet, offline and very secure.  But does the latest Bitoin Core wallet or Armory wallet show (display), or let the user see that private key?


texts: I keep hearing people say that 0 confirmations are safe at small dollar amounts because it would take more money to do a double spend hack. At what value does it start to become unsafe to trust a 0 confirmation transaction?


texts: How exactly does short selling with Bitcoins work?

texts:
Bitcoinica does (or did) offer short selling, but the question is how?

If I fund my account with 100 BTC and I want to short BTC, can I do that, or do I need USD to do that?


texts: Is there a remote, trustless bitcoin API that doesn't require anything (blockchain/SPV headers) to be stored locally?

texts:
This question asks about how to work with bitcoin via an API without requiring a local blockchain. The only answer is about blockchain.info's JSON API, but it appears that unlike the web version of blockchain.info, the JSON API requires the account passwords to be sent to the server.

Is there another remote API that allows one to perform various bitcoin operations without compromising security - without sending private keys anywhere, but rather signing transactions locally? The API should not require any downloads - SPV does not fall under this category - but should just be a remote API to the bitcoin network that doesn't require any state / bootstrap from its client.

If I recall correctly then Stratum was supposed to be this API. Did it ever take off?


texts: What are some affordable options for running a full node?

texts: I would like to start running a full node so I can start building bitcoin/lightning applications, but my laptop doesn't have the storage to do so. Does anyone have any suggestions on how I can affordably run a full node? I was thinking of running it on a remote server, but I'm also not sure of what I should look for in a service.


texts: Will Bitcoin copy Best Features of Litecoin, Ripple, if its Open Source?

texts:
Proponents of Bitcoin always mention that Bitcoin is Open Source, so if any better cryptocurrency comes along, Bitcoin can just copy those features in their open source.
Both Litecoin and Ripple have faster transaction speeds and more transaction capacity.
So why hasn't Bitcoin just copied those features, to improve itself?
We already know Bitcoin has current feature pull requests, and many of the nodes are agreeing to the changes. So why can't they upgrade speed/and capacity immediately?
Who approves the feature and bug code reviews in Bitcoin?
https://github.com/bitcoin/bitcoin/tree/4405b78d6059e536c36974088a8ed4d9f0f29898


texts: What benefits does Bitcoin have that other cryptocurrencies do not?

texts:
I have heard several times Bitcoin being called "the king of crypto." It makes sense when you look at how the coin surpasses all the altcoins in terms of market capitalization and trading volume. No doubt that BTC is dominant in the crypto market.

Why? Why do people prefer to buy Bitcoin over other cryptocurrencies? If you disregard the sheer popularity of the coin, I don't see what other value it has and why there is such a high demand.

The most notable argument is that people buy BTC for international money transfer and buying/selling. However, it seems that BTC would not come close as a perfect candidate for that. Stable coins (ex. Tether) having less volatility would be much better for such transactions. It seems pretty obvious that people and stores buying and selling in stablecoin would be so much better. Using such alternative can provide trust for customers and sellers that what they thought they paid or accepted will actually be what they thought of the upcoming day.

There are a lot of perks for using cryptocurrency. Transaction fees are minimal and transfer is speedy. There is potential for international money transfer, and it is not really tied down to massive regulation and manipulation. However, I'm just not finding the perks of why BTC is the best coin to do all these things.

If Libra is introduced as a stablecoin with a company like Facebook supporting it, why would there be a demand for BTC? Why is there still demand today when Tether can serve as a stable medium of transaction?

Ultimately, is BTC mostly only bought for investment/speculation or is there a real use for using this currency today where there are so many other altcoins to choose from?