texts: Can separate Bitcoin chains be merged back?

texts: After a fork in a given chain, is it possible to merge the two chains back together so that they share the same blockchain?


texts: What is the most widely distributed crypto currency?

texts:
I've been doing research to find a crypto-currency that is "fairly" distributed among the population. Being "fair" is quite subjective. We can all agree that 10 people that control a coin is not fair, but what about 100? or 1000? or 10,000?

So the question is, which crypo currency or currencies have the most distribution? And the other question is distribution the same as adoption?


texts: I sent some USDT Tether to a Bitcoin Paper Wallet. Can I still claim it back?

texts: I sent some USDT Tether to my bitcoin paper wallet. I have the private key, but how do I extract my USDT from this paper wallet? I also have some left over BTC too.


texts: How can I get my peer's ban score for my node?

texts:
If I call getpeerinfo through RPC on one of my nodes, it gives me a list of info about my peers, including my peer's "banscore" for each of its peers.

I would like to do the reverse. Can I get my peer's ban score for my node?

Or maybe there isn't a way to do this because it would allow peers to misbehave in small ways and keep track of how close they are to getting banned.


texts: Does a LN route with N channels at most require N-2 fee payments?

texts: Assume we have a route n1 -> n2 -> n3 -> n4. My intuition here is that n2 charges n1 a fee and that n3 charges n2 a fee for routing payments. However, there's no fee for the last hop where n3 forwards the payment to n4. Is this correct? And if so, is this just an implementation detail, or is this somehow enforced on the protocol level?


texts:
Does anyone know whether exchanges usually round values or truncate them instead?

Different exchanges support different resolutions for prices and amounts. For instance, BTC China supports 2 decimals for prices and fiat amounts (in CNY) and 4 decimals for BTC amounts.

Now, if I buy, say, 0.625 BTC at price 1621.37, I would get 1013.35625 CNY, but since fiat amounts are allowed to have only 2 decimals, that number will lose the extra digits. But will it become 1013.36 or 1013.35 (that is, rounded or truncated?).

This can be verified empirically for any given exchange, but I was hoping someone already knew the answer, either for specific exchanges or a general rule that most exchanges follow (if that were the case).


texts:
When I try to send BTC i get error: BitcoindException(super=com.neemre.btcdcli4j.core.BitcoindException: Error #-26: 66: mempool min fee not met, code=-26).
My wallet is on blockchain.info, I set hight fee: priority, 1000,2000 and 3000 sat/b. And i get same probleb. Help me plz. Why can not I send btc??


texts: Coinotron wont show updates from cgminer

texts:
I type this into command on windows

C:\Users\developer\Desktop\cgminer-3.7.0-windows\cgminer.exe --scrypt -o stratum+tcp://coinotron.com:3334 -u exploithb.1 -p x

and it looks like its working, Im getting 1.4 MH/s for lite coin. But when i log into coinotron i don't see my workers Speed value and It stays at 0.0 KH/s. Could it be that I'm doing something wrong? I let it sit for a half hour to see if i see any updates and nothing ever shows up.


texts: Why is the Schnorr verification formula working and actually verifying the validity of a signature?

texts:
Reading the bottom of page 2 of the Musig Paper we can find that a Schnorr Signature for a cyclic Group G of prime order p with generator g is a tuple (R,s) where

R = gr for a random secret r and
s=r+cx where c = H(X,R,m) for a message m, some Hashfunction H and the public key X = gx corresponding to the private key x.

It is further stated that such a signature (R,s) can be verified using the equation gs = RXc
I would like to know why that last equation proves the validity of the signature?


texts:
Is the wallet ID you use in your blockchain.info wallet the same as your public address where others can send bitcoins?
And the 'Backup Phrase' is the same as your private key?
Maybe if someone could explain all the levels of authentication in the Blockchain.info wallet?


texts:
My question is should I allocate another ~140 GB of disk space for BCH full node?
Thanks!


texts: How can the wallet identify public addresses are linked to a private address

texts: As the wallet can generate many public addresses from a private address. How does the wallet know that any transaction from or to the wallet is for that private wallet if the in and out can be any number of public addresses.


texts: How can I view the Blockchain locally on my machine?

texts:
I'd like to view the blockchain on my Windows 7 machine. Right now I'm looking under roaming/Bitcoin/blocks, and trying to open blk00000.dat . I can't read any of it though, it seems the text is garbled. How can I change the format/open it in a program that makes it look more like the raw block data from blockexplorer or something similar?

Thanks.


texts:
I am doing some tests for an application that signs Bitcoin transactions. I already downloaded the binary files bitcoin-cli,bitcoind and bitcoin-wallet from bitcoin.org. I need to know that the seed of the wallet created by regtest. It is available when the bitcoin-wallet -regtest info command returns:

Wallet info                                                                             │
===========                                                                             │
Encrypted: no                                                                           │
HD (hd seed available): yes                                                             │
Keypool Size: 1999                                                                      │
Transactions: 103                                                                       │
Address Book: 2

I need that seed for run recovery on my app and check if it sign correctly a Bitcoin transaction.

Thanks in advance


texts: Posted elsewhere but I'll paste here too: I just tried to transfer BTC from Exodus to Coinbase but accidentally used the BCH address on coinbase and now I've lost all my funds. Any one got any sort of help whatsoever??? I'm an idiot I know and i'm freaking out


texts: settling timelocked contracts based on amount of time elapsed in Lightning network

texts: Suppose in a payment route A->B->C, A desires to pay 0.01 BTC to C. It locks in 0.01 BTC with B in the HTLC having timeout period of say 2 days and B locks 0.01 BTC with C in HTLC having timeout period of 1 day. Now can something like this be done that if C delays in revealing the preimage say takes 1/2 day, then it gets 0.005 BTC and 0.005 BTC is returned to B. Can the contract support such dynamic settlement of payment based on amount of time lost? In the worst case, if C doesn't respond then B gets back full 0.1 BTC.


texts: How is a Ripple address constructed? Is it similar to how a Bitcoin address works albeit with a different net byte, or are there some more differences?


texts: Setting up my BFGMiner with two AMD GPU's

texts: I have two AMD Radeon 7770's in my rig. I am able to get the command prompt of BFGMiner to run fine up, to the point where I need to add my devices (GPU's). I am not sure what commands to use or where I can find the instructions I need. Any advice would be helpful. Thanks.


texts: How do I get Avalon Miner Temperature from console?


texts: Converting NodeID and BitcoinKey from Lightning Network (LND) logs

texts:
From the LND logs I have something like this (I changed some characters for privacy):

NodeID1: ([33]uint8) (len=33 cap=33) {
 00000000  02 19 8b 61 42 18 89 24  74 fc 95 ed 64 c4 77 91  |.9.a@(.$t...d...|
 00000010  e9 94 97 50 42 d0 bd 7e  95 91 b0 ec 41 28 ab ac  |...PB..~....A(..|
 00000020  e4                                                |.|
}

BitcoinKey1: ([33]uint8) (len=33 cap=33) {
 00000000  02 63 a4 ca a4 63 8c 3c  43 fc 65 8a e5 7c b5 f8  |.c...c.<C.e..|..|
 00000010  a7 8f f5 a4 d8 2e ad 0a  83 3a 17 e1 e8 1e c8 c8  |.........J......|
 00000020  91                                                |.|
}

I read and checked some docs and services, but the result is wrong.

What are the steps to obtain the node pubkey and the Bitcoin address?

I fear that similar questions have been already answered, but I'm still not able to answer mine.


texts: Can you create a valid p2sh transaction with the redeem script in the scriptsig alone?

texts:
From my understanding, for a p2sh transaction to be valid the redeem script must hash to the same value as the output script being used to fund the transaction.

So can't you just put the redeem script of your address in the scriptsig and the transaction will be valid?


texts: Running Bitcoind as a service on windows 10

texts:
So I am trying to run bitcoin daemon as a service on windows 10, so I don't have to keep starting it.

I have tried the following command:

sc create BitcoinServer binpath= "C:\Program Files\Bitcoin\daemon\bitcoind.exe -regetest" start=auto

Which creates a service, but when I try to start that, I get an error:

Is there any way to create a bitcoind regetest service?


texts: Bitcoin client on OpenBSD - compile error(s)

texts:
I am trying to install/compile from source BITCOIN 13.1 on OpenBSD 5.9 or 6.0. Based on the document build-openbsd.md I followed the step by step description, but fell on an error at the end of bitcoin compilation:

gmake[2]: /obj: Command not found

Makefile:9028: recipe for target 'obj/build.h' failed

gmake[2]: *** [obj/build.h] Error 127

gmake[2]: Leaving directory '/home/volker/Bitcoin/bitcoin13.1-src/src'

Makefile:8626: recipe for target 'all-recursive' failed

gmake[1]: *** [all-recursive] Error 1

gmake[1]: Leaving directory '/home/volker/Bitcoin/bitcoin13.1-src/src'

Makefile:558: recipe for target 'all-recursive' failed

gmake: *** [all-recursive] Error 1

I can see it complains "/obj" directory, but this directory for sure does not exist. There is a "./src/obj" directory, but this is empty...
Not sure were the error comes from. I can also see some issues with boost. I have a logfile, that I can provide on demand...


texts: How many FPGA can be attached to one computer?

texts:
I am looking at this. Dual FPGA X6500 Mining Card Rev 3 (Without Heatsinks)

So we connect the card via USB and the card will mine?

Should I buy one FPGA or several ones? Where do I attach the FPGA? PCI? USB?


texts: How do I buy something from someone with bitcoin?

texts: I want to meet with someone in person to buy an item with bitcoin. What's the best way to go about this transaction?


texts: Is it possible to mine Peercoin and Litecoin simultaneously on the same machine?

texts: Using GPU(s) for Litecoin (scrypt, Cudaminer) and a USB ASIC for Peercoin (SHA-256).


texts:
If I wanted to close my bank account and perhaps set up a direct deposit through my employer, is that possible?

Also, will there or are there any Bitcoin debit cards?

I am still trying to understand this.


texts: in PHP how to calculate full uncompressed public key from a short 02/03 pubkey?

texts:
in PHP how do i create the full public key from a compressed one?

my test key is
026a04ab98d9e4774ad806e302dddeb63bea16b5cb5f223ee77478e861bb583eb3

and the uncompressed one is
6a04ab98d9e4774ad806e302dddeb63bea16b5cb5f223ee77478e861bb583eb3
36b6fbcb60b5b3d4f1551ac45e5ffc4936466e7d98f6c7c0ec736539f74691a6

can this be done via openssl?

thanks for any helpful answer!!


texts: Fees from portals like coinbase or bitestamp to Bank/Credit Card

texts:
there is something not really clear to me in the buy/sell process.

When I sell bitcoin on sites like coinbase I am requested to pay a 1% fee. What about the fees to transfer the money back to my bank account (or Credit Card)? Are they included in the 1%?

Thank you


texts:
My friend transferred 0.00369135 BTC from coinbase to my zebpay , but i received only 0.0028 BTC . Why the difference in numbers ?

Please let me know

Thanks


texts:
At current exchange rates, it looks like the standard transaction fee is on the order of tens of cents (USD).  Inclusion of the standard transaction fee means getting the transaction picked up within minutes.

Conversely, zero transaction fee transactions may not be picked up for days.  It also seems to be the case, at least for now, that transactions in limbo like this may be double spent by reissuing with a higher transaction fee.  See earlier discussion here:  Could any standard fee transaction be double spent by using a higher fee?

One can imagine that in the longer term there might be a market equilibrium in which a certain floating minimum transaction fee is required by miners to guarantee processing, and that sellers might not deliver/perform unless that fee were included in a payment.

Are there ways to estimate what the minimum fee might be?


texts: Creating a bitcoin/litecoin miner with Javascript

texts:
I am a web developer and looking for well written technical documents about how bitcoin/litecoin works, what is the workflow, what is the algorithm and how can I write a miner from scratch by using JavaScript (or similar).

It will be a kind of hobby/portfolio project, so I am not worrying about the performance and the other possible issues.

Thanks in advance.


texts: Opening channel with whole wallet balance in LND

texts: I was looking at help output of lncli openchannel and was wondering is there a way to open channel using whole current wallet balance, so that wallet balance minus opening transaction fee is commited to the channel? In c-lightning I can use all as a value for satoshi argument of lightning-cli fundchannel to do that.


texts: Does GDAX have weekl buy and sell limits?

texts: I understand that CoinBase has weekly buy and sell limits. Does GDAX have this as well?


texts: Transfer BTC between two wallet in two different devices?

texts: I have to format my pc, so I have downloaded a BTC wallet also on my tablet. Is there a way to send BTC without commission fees?


texts: Using Bitcoin or another Altcoin for Decentralized Database Storage

texts:
I was wondering has there been any attempts on using the blockchain as a decentralized database storage system? Would it be feasible to use it on Bitcoin or another Altcoin and if so which altcoin would suit it best? I would imagine Bitcoin would have the most redundancy as it has the most nodes.

Say for example I have my CMS and I wanted to store my user records in a blockchain. Or is there another practical example when using blockchain for storing database records?


texts:
I understand with Ripple that anyone on the network can offer their own currency.  Someone cited the example of airline frequent flier miles.

Airline miles, in my experience, come in whole numbers.  I.e. 2000 miles, not 1999.5 miles.

If I start trading miles on Ripple, someone could easily offer to buy or sell in fractional units.  So balances in ripple wallets could be 1999.5 miles, right?

Is there any way in Ripple to force the units of a particular currency to be integers?

I'm asking about what appears in the wallets.  I know that within the system the units are integers.  I.e. 1 XRP = 1,000,000 drops.  I'm asking about the balances shown to users in their wallets.


texts: In Bitcoin Core, are compact blocks pre-filled with more than just the coinbase?

texts:
In the "How are expected missing transactions chosen to immediately forward?" section of https://bitcoincore.org/en/2016/06/07/compact-blocks-faq/ it states that "To reduce the number of things that need to be reviewed in the initial implementation, only the coinbase transaction will be pre-emptively sent."
I found https://github.com/bitcoin/bitcoin/blob/master/src/blockencodings.cpp#L23 which still lists pre-filling more than the coinbase as a TODO. I was wondering if that was in fact correct or whether it was an erroneous TODO. If not, is anyone working on that functionality or is there a reason it was never implemented?


texts: Understanding default bitcoin wallet in bitcoind

texts:
I am new to block-chain, so please bear with my questions. I need to understand the basics of a bitcoin-wallet.
So I have setup a bitcoin full node using bitcoind in running in testnet mode. As I understand that by default a wallet is created. Now when I am trying to get the address of the wallet by this command bitcoin-cli -testnet getaccount "", I am geeting an empty list.
So is there no default wallet as such, also how do I create a new wallet? As I understand that a bitcoin wallet is basically a pot which holds several child addresses?


texts: 19 out of 24 words of BIP39 passphrase (brute-force last 5?)

texts:
I have managed to lose 5 words of my 24 word Ledger Nano S recovery phrase. I have words 1-19 but I am missing words 20-24.
I have significant holdings on the wallet so would very much like to recover it if possible.
The passphrase is a BIP39 mnemonic (see https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki).
I have the bitcoin and ethereum public addresses for this mnemonic. I am wondering if it's feasible to brute force the passphrase.

Each word is 11 bits (2^11 = 2048 possible words).
The last (24th) word of the passphrase is of the following form [3 random bits][8 bit checksum].
Therefore I only have to check 2^(55 - 8) = 2^47 = 1.4x10^14 combinations.
I would have to compute SHA-512-HMAC with an iteration count of 2048.
As far as I understand, that means I'd have to compute 1.4*10^14 * 2048 = 2.87*10^17 hashes in total.

Is there any hardware out there designed for this? I am aware of ASICs that compute sha-256 hashes but not sha-512 hashes.
Perhaps I could tweak one to work with sha-512 since they are very similar.

Assuming a fairly typical ASIC hashrate of 1TH/s (10^12 hashes per second), I could exhaust the search space in 2.87*10^5 = 287000 seconds = 3.3 days. I'd probably get there sooner, of course (expected 1.65 days). Time is not something I am worried about. Even if I have to wait months, I don't mind - so if I can get 10GH/s at a reasonable price, that would be great.

I would really appreciate any help/information you could provide to help me out and make sure I haven't missed anything.
I could also use GPUs for this (I calculate I can run them at roughly $1/10TH - so it would cost me $28.7k to exhaust the search space, which I will do if there are no cheaper options).

Many thanks,
James


texts: if bitcoin miner(s) changed the UTXO set would the bitcoin nodes reject the blocks?

texts: if so, would this cause a Fork? or what would happen?


texts:
I have a little bit confusion about addresses segwit and not segwit.

I can see P2WPKH and P2WSH from this link https://en.bitcoin.it/wiki/BIP_0173, and they are segwit and start with bc (mainnet) or tb (testnet).

But I can see even P2SH, start with 3 nested P2WPKH or P2WSH, and that address start with 3.

Then When we speak about P2WPKH and P2WSH we mean Native and start with bc, or We can have even P2WPKH start with 1 and P2WSH start with 3?

when I create

bitcoin-cli getnewaddress "segwit" "p2sh-segwit"

which kind of script I have? P2PK?


texts: Original bitcoin core has one script.cpp.where is interepreter for it?I want to write hello world compiler to understand this.?

texts:
How to understand script.cpp and its interpreter.I understand register and postfix operation.
I want to understand how script is parsed into machine code.Can i write hello world such as only pushing value into the stack.


texts:
To speak the truth, I don't really know what getmemorypool did before, I'm having a hard time trying to figure out.

And why is getmemorypool obsolete? What replaced it for internal work generation?

I don't find much documentation about it in search engines.


texts: How do hierarchical deterministic wallets work transaction-wise?

texts:
As far as I know (and as explained here) hierarchical deterministic wallets keep a master key pair (private and public). When using them the public key is newly generated in every transaction. I understood that child keys are generated by elliptic multiplication of parent keys. Benefits associated with HD wallets are claimed to be:

Better privacy because new public keys are generated in each
transaction;
It is only needed to store one master private key, as
all the other keys can be derived from it; and
It is possible to
store the master public key on an insecure server and still generate
as many addresses as needed without having to leave the private keys
on that server.

While I do more or less understand the theoretical concept, I struggle with the practical implementation of the process, and in particular with how does the system associate the balance from several transactions (allocated to different derived public keys) to the same bitcoin "account" or master public key?

Anyone able to make a "for dummies" clarification?


texts: Bitcoin Core - When is fAllowWitness evaluated to true?

texts:
In Bitcoin Core, when is fAllowWitness evaluated to true?

transaction.h

const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);

In particular, I cant figure out the value of s.GetVersion()

Thank you


texts: Bloom Filter Response Processing In terms of Full-node

texts:
A SPV node have to work somethings to see whether his transaction is exist or not.

Construct his filter with hash of transactions {his transactions, other1, other2, ..., otherN}
filterload is filled to process his filter by full-node (by BIP-0037)
Send to full-nodes

Okay, these are responsible for SPV node and let me take a view of full-node received the filter.

Lookup chain to find transaction(K) with filterload

What...? hold on.. how can the full-node know that transaction(K) is what? filterload has no any information of transactions(K).
filterload = { filter, nHashFuncs, nTweak, nFalgs }
Nobody doesn't explain about this in the web, including BIP-0037. Just explains only what is a bloom filter.
I think that full-node must know what transactions(K) are to find on his ledger, otherwise full-node have to see entire chain and this doesn't make sense.

So.. I'd like to know the proper procedure on full-node received the filter by SPV node.

Sorry for my English.


texts: How to check Bitcoin wallet balance without any API

texts:
I am building an application and that will involve large set of bitcoin wallets and need to keep on checking for balance. I don't want to use any third party APIs as they all have hourly/secondly limits.

Is there any way I can check bitcoin wallets balance without any API? I am not sure is Bitcoin Demon and Bitcoin Core is for this purpose. Can anyone please suggest me the best way to verify bitcoin balances and transactions without any limits.


texts: Why are there not mnemonic-seed words in Turkish especially considering the increasing rate of bitcoin adoption in the country?

texts: How come bitcoin doesn't have Turkish words as wallet seeds especially considering the increasing rate of bitcoin adoption in the country ?


texts:
Apologies for the noobie question.
I was wondering how a range of wallet addresses (eg. BTC address 33ELbMhwHw5AaKHU4u3MzVSFvvK7aa7HZL) is algorithmically converted into seeds (eg. 12 words). Any help?

I tried to google around but I only find articles related to ledgers, wallet recovery and so on.

Thanks


texts: Bitcoin miner's earnings from transaction fee per block?

texts:
I understand the basic concepts of Bitcoin and Blockchain.

As I understand, any bitcoin transaction has a transaction fee that is user adjustable. This needs to be above a certain value which can change over time for the transaction to be recorded on a block. Currently this value is about 300 satoshis/byte.

What I can't understand is how the miner is paid this amount?
If a miner mines one block which is 1 MB in size, then the miner can record ~4424 transaction on that block (assuming ~226 bytes per transaction).

If everyone who did those transactions used the 300 satoshis/byte transaction fee this translates to ~ 3 Bitcoins.

A bitcoin block is worth 12.5 bitcoins currently. Does this mean that the miner gets ~15.5 bitcoins per block? (assuming the mining is mining solo and not in a pool)

P.S. I obviously tried searching this online and while I am sure the answer is out there but because of hot keywords like bitcoin and blockchain, most result eventually end up to articles, "What is Bitcoin?" xD


texts: Will reinstalling bitcoin core give me access to the previous wallet?

texts: If I reinstall Bitcoin Core, will my previous bitcoin wallet still be accessible or will I get a new wallet? The previous wallet backup became corrupted. Will reinstalling give me back my old wallet or is my wallet lost forever? I don't have a wallet backup.


texts:
I had a fraction of BTC on blockchain.info before the 1st of August and I didn't touch them at all afterwards.

I never got my private keys (nor the 12 words) from my blockchain.info wallet (or if I did god knows where they are).

Question: if I try to get my private keys (bip39) now will they be the same so that I can get BCH following this guide http://www.coinpurveyor.com/how-to-claim-bitcoin-cash-from-blockchain-wallet/?

Thanks

(PS. another useful guide: https://coinomi.freshdesk.com/support/solutions/articles/29000013719-how-to-get-bitcoin-cash-from-many-wallet-software-services-with-coinomi)

UPDATE - THE ULTIMATE SOLUTION:
https://www.coindesk.com/couldnt-claim-your-bitcoin-cash-btc-com-now-has-a-tool-for-that/


texts: Is the Bitcoin Transaction ID also the "Hash of things to sign" for the signature generation?

texts:
As a random example, is the transaction id:

114be7fea4d3dd0cf2e88a8fa9a56d4ea741efbabd07d61d08cf0810be2254fd

Also the hash that was used as the "hash of things to sign" for the "signature generation" for this transaction?


texts: What is extended master key fingerprint on coldcard?

texts:
On coldcard on
Advanced -> View Identity, there's
extended master key fingerprint
I though this was the xpub from my seed, but even after I changed seeds, it remained the same.
What is it?


texts:
I recently backed up my blockchain to an external drive and restored my computer from Windows 10 to XP. Afterwards, I copied the blockchain back to my hard drive and downloaded a portable copy of Bitcoin Core and ran it. It said it had many hours to sync, and I left it overnight. When I came back, it had crashed with XP's message about it needing to close. I opened it again and it said that some part of the blockchain files were corrupt and started syncing from 2009. I restored my backup again and it only had 34 hours to catch up on.

Today I got up and the same error was displayed. But this time when I reopened it, it only has to catch up on 2 hours. If it works then that's great, but does anyone know what's happening?


texts: Path notation for extended public key of hardened child?

texts:
Typical path notation for a BIP44 child private key would be something like:

m/44'/0'/0'

The public key is

point(m/44'/0'/0')

Where point is the ECC multiply function. Is there any better notation than this? It would not be right to use M/44'/0'/0' as this path is not derivable.

Is there any standard notation for the xpub calculated from a hardened child private key?

(Note: I'm looking for notation that would be useful to parse and then re-derive this key, not necessarily the type of notation that would be intuitive in an academic paper.)


texts: Turing an old laptop into a bitcoin miner

texts:
So I have an old laptop that was passed down to me, and I want to turn it into a bitcoin miner, I don't have any experience with bitcoin mining; its got 2gb of ram and some pentium. it will be running all the time.

Thanks in advance
Holden


texts: why can I not recreate my blockchain.info addresses?

texts:
I'm trying to generate a list of all my Addresses ever used on blockchain.info wallet with balances prior to august 1st,2017. i used the tool below to do this:
https://github.com/iancoleman/bip39
But when I feed this with my Twelve word backup phrased from blockchain wallet, It does not work and gives the error "one word is not listed in dictionary!"
what's the issue? what should i do?


texts:
I'm looking to sell bitcoin from a paper wallet into fiat.
So far my research is suggesting that a good way of doing this may be to transfer the paper wallet to LocalBitcoins wallet and sell from there. As I understand it, this incurs a fee to bring into the LocalBitcoins wallet, and then a fee to sell. In order to get the paper wallet BTC into the LocalBitcoins account, I would surely have to import the paper wallet into a software wallet first in order to transfer them to LocalBitcoin.
This means it would be something like:
Paper Wallet > Software Wallet > LocalBitcoin Wallet > Sell on LocalBitcoin
The above seems quite convoluted. I don't mind convoluted if it saves on money and is relatively secure. But it would be good to get some advice on either reducing the number of steps in this process or an improved method of selling from a paper wallet. Note that I want to spend all of the BTC in the paper wallet (which is a fraction of a BTC) so the software wallet does not need to be trusted beyond the importing/spending part of the process.
Also, if I must do the software wallet first, would be good to get recommendations on good software wallets. I assume I can spend bitcoins from a software wallet that I have "imported" my paper wallet into rather than "sweeped"?
I'm using the term "software wallet" to include online hosted wallets and local computer wallets alike here. But will play close attention to any advice given on this.
I also have a Bitcoin.com account, if that's any use.


texts: Help in understanding block header input data for scrypt

texts:
I am an computer engineering student trying to understand how the Litecoin scrypt algorithm works. I downloaded the Github cp-uminer. Can someone give me some examples what the input data look like for the miner's scanhash_scrypt function input argument work.data? I know it is a 640-bit (80 byte) header. But I can't find any document that describes the fields of the header, little-endian/big-endian etc.

Also, some comparison with bitcoin's SHA confuses me. In the cpu-miner's scrypt.c, it takes input argument data and runs SHA256 transform on it. For Bitcoin, I would see that there is a conversion to big-endian before running the SHA256 transform. Is this expected?

Thanks!

Regards,
SC


texts: How do I set CPUminer to Scrypt instead of SHA256?


texts: Feasibility of a "High horsepower" attack (based on difficulty -4x adjustments)

texts:
This is really Part 3 of this earlier question.

Given that the QT client is hard coded to never adjust difficulty more (or less than) a factor of 4...

What realistic scenario would cause the difficulty to decrease by a factor of 4?

If the hashrate were to decrease by a factor of 4, then that means current miners are trying to keep up with a difficulty that is incredibly hard given their relatively weak horsepower.

When network hashrate drops this way, I envision:

Transaction confirmations will take a very long time
The interval between blocks would get exceptionally long
It will take a very long time until 2016 blocks are mined before the target is adjusted back.
It is relatively easy for the attacker to turn on his hardware at the 2017th block and DOS the network again.

Bottom line, I doubt the -4 difficulty would ever be reached... but could be exploited for malicious purposes.

So assuming a big loss in mining power occurs:

How much horsepower must be added and then lost for a 4x difficulty to be realized?
How long will it take a transaction to be included in a block/confirmed (worst case)?
How long will it take for the chain to return itself to normal levels?

Finally,

Are the effects of a "high horsepower user" who intentionally switches on, then off a massive mining rig enough to disrupt Bitcoin network operations?  To what end?

Disclaimer: I know that 4x is not the only disruption that can occur, since lesser magnitude attacks would be equally annoying but want to forecast worst case scenarios.


texts:
Any of a kind Bitcoin wallet need to share private key on the internet-connected machine.

Bitcoin client has no responsibility for to keep private key secure. If your's machine connected to the internet, your keys can be hijacked, because your machine can be hacked before you import keys.

The questions is, how to trust any of existing wallets to store private keys?


texts:
I've been running bitcoin core on an android device (nexus 5x) and emulator, and sync on testnet always fails at around 3% progress

the last thing logged is

“pre-allocating up to position 0x900000 in rev00006.dat”

core crashes and when restarting the sync process never restarts getting stuck at

“Failed to open mempool file from disk. Continuing anyway”

Prune is set to 550mb and the device has 2gb ram but 70% seems to be taken up by the OS

Is this issue caused by a lack of ram? Or likely something else?


texts: Can decentralized blockchain technology like bitcoin be used to store medical information?

texts: For example patients get private key, providers get public key?


texts: Retrieve all Unspend Output given a priv key

texts:
Is it possible to retrieve all Unspend Output transaction given the private key?
I have noticed that different wallet give me different balance for the same Private Key. For instance, Atom and BitPay give the same result but they use BIP44. Exodus and Defi Wallet give the same result and they use BIP84. On these wallets I have given the same Private Key but every wallet sees part of the Unspend Output. Hence my question.
Thanks
https://bip39.org/


texts:
I have a technical question regarding the signrawtransaction function in Bitcoin core when signing a partially-signed transaction.

I have tested different scenarios and signrawtransaction will always sort the signatures in the correct way in the scriptSig, regardless of the order the transaction is signed one-by-one.

Is this achieved by analyzing the scriptSig of the partially-signed transaction when signing, and then verifying each signature in the partially-signed transactions scriptSig against all public keys in the redeemscript and finally ordering them correctly? Or is there a better way of doing this?

Unfortunately I don't understand how this is done by reading the C-code of bitcoin core.


texts:
Well, I am starting now with bitcoin in Brazil (realizing my country is a non-concern in terms of the answer), I noted that final value change depends on exchange used.

So, if I buy a bitcoin in MERCADOBITCOIN (Exchange 1) for R$ 2383,00, I can sell this in FOXBIX (Exchange 2) for R$ 2500,00 in same minute. Is this difference in value normal ? Why does bitcoin have different values across different exchanges?


texts: Using ZeroMQ of bitcoind to monitor addresses?

texts:
I'm developing a system which should monitor incoming transactions for the local addresses (addresses in this node's wallet).

It would be great to use high-performance ZeroMQ for this. Is it possible?

I know I can receive notifications about new transactions from it. But notification only contains transaction ID. How do I know if it's related to one of the local addresses?

Do I need to make RPC call for each transaction to find it's output address? This seems extremely ineffective, cause there a lot of new transactions and by making so many RPC calls I will just flood the server.

Is there a better option?


texts: How does a filterload client that recieves an incoming transaction retrieve the transaction it's spending?

texts: Suppose that your SPV client receives an incoming transaction. How can it tell whether it spends a real outpoint? If you knew the block, you could add the txid to filterload and request the block again, but I'm at a loss for how to implement it otherwise.


texts: For 5 days now my block download has been frozen at 57%. I tried downloading a new wallet to a different computer (which did download all the way), but I can't figure out how to pull the information from my frozen wallet to this one so I can recieve my bitcoins. Or how to get the blocks to finish downloading on my original wallet. Any help would be much appreciated, I need my money asap!


texts: decoded raw transaction size & vsize mean?

texts:
I have decoded my raw transaction using decoderawtransaction, I got these value

"size" => 259
"vsize" => 259

is that block size ?
if it does, is that byte or killo byte ?
I want to calculate miners fee based of block size


texts:
I am an accounting student and I recently read about bitcoins, I was wondering if anybody could clear up my questions from my basic understanding of the bitcoin system.

Since Bitcoins on a whole, derive its uniqueness from the system of maintenance of a public ledger and an important part of this, are the miners, who are provided an incentive in bitcoins for for their hash creation. The cost of hashing and recording it in the public ledger is technically, the bit coins paid to the miner. My questions are

- Who bears the burden of the cost? Is it the user or is it the network?

- If its borne by the network, wouldn't this cause an increase in circulation      of bitcoins in a network and lead to reduction in their value making them unstable?

- If the this cost is borne by the user, then how does it make it an alternative to native banking transaction cost?

2) Based on what I have read online, so far, the circulation of bitcoins is capped of to a certain limit to prevent deflation but my question is

- If the mining of bitcoins also lead to circulation increase, how can the system handle the volume of transaction relating to a global economy? How would this effect the public book keeping system and the miners ?

Can somebody please help me understand this ?


texts: Did I lose my Bitcoin cash sending from an exchange to a Bitgo bitcoin wallet?

texts: No transaction is showing up on the blockchain or at Bitgo Bitcoin wallet.


texts:
I'm sure this will be simple to experienced Binance users...but I cannot figure out how much I actually lost after my Binance Loan got liquidated after the latest crash.
Here are screenshots of what happened:

Can someone tell me:
How much bitcoin did I loose through this liquidation?
Thanks!


texts: Why the timestamp component of the block header?

texts: What is the reason for the timestamp field in the block header? Surely the nonce should be the only property that changes? Should the nonce reset to 0 everytime the timestamp changes?


texts: How to get private Keys from Wallet using bitcoin-qt

texts:
createwallet "MyWallet"
getwalletinfo
{
  "walletname": "MyWallet",
  "walletversion": 169900,
  "format": "bdb",
  "balance": 0.00000000,
  "unconfirmed_balance": 0.00000000,
  "immature_balance": 0.00000000,
  "txcount": 0,
  "keypoololdest": 1617197424,
  "keypoolsize": 1000,
  "hdseedid": "4da0242dbf5124f4f05e6ffaf6bd94c51a9d7858",
  "keypoolsize_hd_internal": 1000,
  "paytxfee": 0.00000000,
  "private_keys_enabled": true,
  "avoid_reuse": false,
  "scanning": false,
  "descriptors": false
}

But I don't know what to do next. A lot of commands are deprecated.


texts: Is it possible for a slow computer to beat the world mining Bitcoin?

texts:
I've heard it is not profitable to mine bitcoins on a regular computer via CPU anymore. I accept that.

However, if you did install a miner onto a regular computer and that computer randomly generated "guesses" 24/7 (in a non-sequential fashion). Isn't it quite possible that it could make a lucky guess and beat everyone else mining?

Or, is that absolutely impossible?

I'm thinking about trying my luck at this (without joining a pool) (for fun) if it is possible. If impossible, then please explain why.


texts:
We know that the hash of the previous block is included in the header of the next block. So, if an adversary change the data in the block no. 10, then they hash of it will be changed and the header of the block no. 11 will be no longer  true.
But, in the textbooks that I read to understand the blockchain, the said that the change in block no. 10 will change the whole blocks till the header of the genesis block prevent.
Why the change of the data do backward from no 10 to the first not from no. 10 to 11 and so?

See this for example:
Imagine this for a second, a hacker attacks block 3 and tries to change the data. Because of the properties of hash functions, a slight change in data will change the hash drastically. This means that any slight changes made in block 3, will change the hash which is stored in block 2, now that in turn will change the data and the hash of block 2 which will result in changes in block 1 and so on and so forth. This will completely change the chain, which is impossible. This is exactly how blockchains attain immutability.


texts: How to create raw transactions with custom fees?

texts:
I have a website where users can send and withdraw funds using Bitcoin. I would like to give them the possibility to use different fees (low, medium and high) instead of a fixed fee or to let bitcoind choose the fee. I can't setup  a default fee or be changing it at runtime because then if a user decides to use a high fee and a lower one, it could happen that the user with the high fee is assigned as low or vice versa.

Therefore, after researching I have come to the conclusion that it is necessary to build the transaction from the UTXOS that my node has. However, it is difficult for me to finish understanding how to carry out this task. I will give an example to explain my problem:
If the node UTXOS is 1BTC, a user has 0.1 BTC in the service wallet and wishes to withdraw 0.07 BTC. I understand that the steps to be taken would be the following:

List all unspent transactions
Select one or more inputs to create the transaction
The fee is calculated as the subtraction between the total of the inputs and the outputs

My doubts at this moment would be:

If I understand correctly, for each incoming transaction we have, we will have an unspent transaction that will allow us to spend the available funds; Then, as long as you have in a database the correct balance to each user (updating that balance with the corresponding fees when withdrawing  funds), so I should only use the same UTXO generated by each user when depositing btcs Or is it possible to use other UTXOs as long as the quantity is the same?
I have read in bitcointalk that the inputs of a raw transaction must be less than or equal to the outputs of that transaction. Is it not possible to use inputs higher than the outs and "return" the surplus funds again to a wallet of my node?
How can I calculate the fee used? I mean, I can decide that I want to use X satoshis/kb but how can I calculate the fee that the transaction will need before I create it? Because if I understood correctly, the size of the transaction I get once I have created such transaction. I do not know if there is a way to perform the calculation that the transaction will occupy in bytes / kilobytes

I have not found too much information about it, so if anyone can help me I would appreciate it.


texts: Does a bitcoin exchange transfers my bitcoins to a "temporary address" when an order is placed (and not yet executed)?

texts:
I am using a digital currency exchange platform to swap between cryptos (Bitfinex, although the specific Exchange shouldn't matter I guess) and noticed something that I wanted to confirm. I started by transferring some Zcash from my desktop wallet to my "Exchange Wallet" on Bitfinex (the t-addr was generated using Bitfinex's "Deposit" functionality). When the transfer was confirmed and my Total Balance showed the correct amount, I placed an order to swap all of the Zcash for Bitcoins; the order is still active (not executed nor canceled). I then incidentally checked my balance on explorer.zcha.in and noticed it was zero, even though the order has not yet being executed. Indeed, by exploring the chain itself I found an actual transfer of my Zcash to another t-addr, with the corresponding transaction being inserted on a block and mined. The questions/comments are:

1) Does the Exchange (to avoid double spending?) temporarily transfer the money to an escrow t-addr until the order is executed? (And when that happens it both clears my Zcash Balance and increments my Bitcoins balance I assume).

2) If the order is indeed executed, I am assuming the Exchange does a second transfer, this time sending the Zcash from the escrow t-addr to the buyer's t-addr. This means two transactions on the chain for a successful trade.

3) On the other hand, if I cancel the order I assume the Exchange transfers the Zcash back to my t-addr, creating another transaction on the chain that needs to be mined. Similarly, if I instead modify the order (price or amount) does the Exchange need to refund my Zcash first, and then do another "escrow transfer" with the updated order parameters? (meaning additional transactions on the chain).

4) Item "3" above implies that several modifications in a given order will create many transactions back-and-forth the chain which need to get mined. Do these "pseudo-transactions" require a fee as well? Also, if I end up canceling the order after several order modifications, will I have generated some "useless" work on the chain for the sole purpose of speculative trading?

Is this the way Exchanges actually work? If so, is there a (safe) way this type of control can be done without creating various transactions which are not "real transactions" in a sense?

Hope the question is not confusing, thank you for any help.


texts:
suppose for the sake of argument that each individual miner has the same amount of hashing power of one hash per unit of time (a "tick").

the probability that a miner solves their block in the next tick increases with the number of hashes already checked, since the nonce space is finite.

colluding miners could agree to pay the coinbase transaction to the same address and thus work on solving exactly the same block.  they could divide the nonce space amongst them and thus exhaust the nonce space faster than solo miners.

by agreeing to redistribute the rewards of their mining amongst them, the colluding miners have an expected payout for the next tick that increases faster than that of solo miners, since they are exhausting their nonce space faster.

so isn't it rational for miners to collude?  could this create a tendency to monopoly in mining?


texts: Possible to restore an Electrum wallet with partial (12/13) seed?

texts:
Long story, but I need to restore an Electrum wallet (version 2.x). I have the seed, except the first word which got ripped off a legal pad.

So with 12 of the 13 seed words, what can I do to restore the wallet? I've tried to look at the word list and test possible 1st seed words, but haven't had any luck. Is there another way to skin this?

Any ideas / help would be very much appreciated. Hoping this isn't a costly mistake.


texts: Use case for multiple inputs in a single transaction

texts:
Is there a way to ascertain a pair or more of Bitcoin addresses belong to the same wallet on the basis an address pair was used as input for a single transaction?

Can I verify the address pair input is not part of a createrawtransaction or fundrawtransaction transaction, for instance from a blockchain explorer?

In which case besides createrawtransaction and fundrawtransaction would multiple inputs within a single transaction belong to different wallets?


texts: Can someone please explain to me if mining with a rented rig is worth the investment. I recently mined but the server went down. Also where does the hashed data go and is it available for my viewing? Thanks so much..


texts:
I've created a docker container of an ubuntu machine, loaded it up with all the dependencies specified in the unix build doc and then built bitcoin and run it with the following command:

./src/bitcoind

after that there's no output or evidence that anything is happening, the terminal is just hanging there, clearly something is going on- but I don't know/can't see what it is.

how can I examine the activity? For instance, see the coins that are being generated in my wallet, etc.

I've tried this proposed solution, i.e. to write

bitcoind getinfo

but I got the error

Error: There is no RPC client functionality in bitcoind anymore. Use the bitcoin-cli utility instead.

Regarding -regtest

I tried with:

./src/bitcoin-cli -regtest &

and I got the error:

too few parameters (need at least command)


texts: I have a Linux machine with an Nvidia GPU (GeForce GTX 760). Is there a tool, rather than writing your own, that can currently mine Bitcoin using CUDA on Linux?


texts: What's the deal with OP_RETURN and length?

texts:
It seems like most OP_RETURN transactions include length as the first byte after the OP_RETURN code. Is this specified anywhere?

Also, the length is sometimes the entire length of the rest of the output, and other times, such as with memo.cash, it is only 2, but there are many more bytes than that.  What is it supposed to be?


texts: Can I cancel an unconfirmed transaction?

texts:
I made a transaction by mistake, fortunately it is still unconfirmed.

Can I cancel it?


texts: What ways does a miner differ from a wallet?

texts:
I'm trying to understand how transactions are broadcast, the time is synchronized, and the chain extended.

I have a wallet on OSX that required me to fully synchronize with the network.  Contrasting with this is the BitMinter client that doesn't need the historic chain.

Can someone help me understand how a wallet and a miner work in a P2P environment with respect to

Network (port) requirements and what protocol
locating peers
The actions taken with each peer


texts: blockchain.info: bitcoin cash from fork no longer visible

texts:
I was previously able to see the bitcoin cash here:

Get BCH from blockchain.info after fork

This no longer works and I'm unable to find it.

Anyone have insight?  I was in the process of moving the BCH the past week and the link has disappeared.


texts: How to download bitaddress.org to use offline?

texts:
The site does not have a download option.

I can save the page using Google Crome by CTR-S, but the version I have saved in this way does not work.


texts:
How to store full blockchain on server and run Bitcoin Core as client only?

I want to run Core wallets on 2 or 3 or even more computers on my local network. The best way to store the full blockchain is to put it on one server on my local network.

I want the Core client to read only the blockchain data and listen for changes from the server but not write anything to the server, like a read-only directory. The server should be the only one allowed to write updates to the blockchain data.

The Core client should write private data to %AppData%\Bitcoin as usual but segregate the blockchain data onto the server.

How do I do this?


texts: blockchain.info API response is coming with a big delay

texts:
I'm using blockchain.info API on my shop. Everything was fine until about 2 weeks ago. The whole procedure and the issue is:
- When a customer place an order, a btc address is created and customer must send a certain amount of funds to this address.
- When funds are received on this wallet, blockchain.info is sending a response to my site that funds are paid.
- Automatic confirmation emails are sent to the customer when I receive this confirmation from blockchain.info.

About 10 days ago, I noticed that the "paid" reply comes with a big delay from blockchain.info. Log shows that there is a difference of about 4 hours between creating the invoice and paid responce. At the same time, I see that customer paid his order (3 confirmations) in 25 minutes (for example) after invoice was created.

As to mention, there were no such issue before. Something changed and I cant understand where.


texts:
I have requested some bitcoin from my friend and gave him the adress that is displayed in the "receive" tab in the electrum client.
After he sent them, I made a request for that amount in electrum and it is apparently "paid", as you may see below.
However, it does not show up in my history as an incoming payment. How do i get it to show up there?


texts: How do the blue encrypted bitcoin paper wallets work?

texts: Via https://www.bitaddress.org I saw you can get a paper wall but with encryption and a passphrase. What are the steps of using the wallet with the passphrase? It seems the address is on the left while the private key is on the right.  So I am guessing the private key is what's encrypted with the passphrase? How would you decrypt it with the passphrase?


texts:
On that date, some erratic out-of-spread trades appeared on MtGox.

The explanation given says that accounts may have been compromised by the CosbyCoin attack on bitcointalk.org. I do not understand how this can lead to out-of-spread orders being executed.

He says the issue is resolved and proceeds to give us a speech about password security and says that we should keep trading "in confidence".

That does not satisfy me at all.


texts: Disappeared xPubs from Blockchain Wallet

texts:
I am using Blockchain Payment API. To overcome the gap limit problem, I created a couple of xPubs. Suddenly I realized some xPubs had been disappeared from the wallet. I can't delete them. I can only archive them. But before their disappearance, the system got some payments. Unfortunately, I can't access that money at all. I opened tickets on blockchain.com Support Page. But for months no solution to my problem.
I shared that xPubs' transactions as an attachment. How can I solve my problem?
xPub's Transactions:
xPub's Transactions


texts:
Let us consider, if someone found a bitcoin block using his pc, then how he can get reward BTC to his bitcoin wallet?
I really don't know how a miner get reward of 12.5BTC to their bitcoin address. Does bitcoin header address contains miner address? if any one know please tell me.


texts: Large pool of addresses means more anonymous? how?

texts: For an average end-user, if bitcoin-qt is configured with a large pool (1 billion) of Bitcoin addresses, then will it increase user / transaction anonimity?


texts:
I've read that addresses alone are a "confusing" way to think about "where" bitcoins "are".  Nonetheless I was formerly (2018) able to correlate what I got from bitcoin-cli commands with what I saw on blockchain explorers like https://www.blockchain.com/btc/address/
e.g. back in 2018 getaccountaddress would list 1 address, getaddressesbyaccount would list that plus a 2nd address, getaddressesbylabel would list those same two addresses, getwalletinfo would show a 0.0003 balance, and listaddressgroupings would also show that balance.
Now in 2020, that online explorer still shows that 0.0003 BTC balance, as it did in 2018, but due to deprecated cli commands, how can I confirm that with bitcoin-cli?
Background... I have been running a full bitcoin node on Ubuntu 16.04, kept updated, so currently Satoshi:0.18.0, and just to experiment and educate myself, I played around in 2018 with a bitcoin faucet until I managed to get 0.0003 BTC.  Then I had the faucet site transfer it to one of the addresses in my bitcoin node's wallet.
For non-deprecated commands I've also found
bitcoin-cli scantxoutset "start" "[\"addr()\"]"
from this question
https://bitcoin.stackexchange.com/questions/92342/how-to-quickly-get-the-balance-of-any-bitcoin-address-with-no-third-party-api however that too shows a zero balance for the two addresses that I can list from getaddressesbylabel.


texts: What new peer services do segregated witness nodes need to implement? In particular, if you want a node to relay both a block and its witness data, how do you request that?


texts: How to integration Blockchain Payment API in Asp.Net?

texts:
I am new to using the Blockchain API. I have tried several times to use
https://blockchain.info/merchant/$guid/payment?password=$password&second_password=$second_password&to=$to&amount=$amount
but it always redirects me to https://blockchain.info/api/blockchain_wallet_api instead.

I don't understand why it doesn't give any response.


texts: How would AML techniques work in Ripple?

texts: Can anyone explain how AML rules, alerting, and FinCEN reporting would work under Ripple?


texts: How do you extract the sending and receiving addresses, and the amount, from a Bitcoin transaction?

texts:
I'm trying to write software in Elixir to do it. I have the source code for BitcoinJ, but it's quite laborious figuring out what it does. If I look on bitcoin.info, I can see this block

https://blockchain.info/block/00000000000000000028d1186d6dc9191a6ec93624141031e31814e22e75e0c5

has transactions including 2c1a83d5a511399f151571ff26925764ef73081251c239dd2eb6904304d7bcba

from which blockchain.info has deduced

1PSfpNCcY9uNh1QEitLLLGaDX5LicnBJhx sent 12 BTC to

3PK9abqzd2oK3yWgESSZ6Ps1wPBBu222VW and 0.0789 BTC to

12AE3fQj1CsSGL9c3aZpkSDz991KUxntvB

I want to find out how it deduced it. Thanks for any information.


texts:
I have read that Previous Block hash takes around 32 bytes in the Block Header. Since it is a SHA256 hash which is 64 characters long, shouldn't it take 64 bytes as well? Similarly, Merkle root and other parameters.

Take a look at the following:
    010000009500c43a25c624520b5100adf82cb9f9da72fd2447a496bc600b0000000000006cd862370395dedf1da2841ccda0fc489e3039de5f1ccddef0e834991a65600ea6c8cb4db3936a1ae3143991

Length: 160

Apparently, it is x2 of what is actually written everywhere.

What kind of encoding is used here?


texts: Would it be possible to generate a memorized wallet address by using a batch of phone numbers?

texts: I was wondering if I was able to generate a bitcoin wallet by using a bunch of phone numbers i remember. I'm sure everyone can recall at least 5 or 10 phone numbers by memory. So in theory I can reference the wallet by just remembering the people thats associated with it. Say my wallet would consist of: john, sam, eva, jesse, and ben. but it would be referenced as phone numbers and in turn gets converted to a bitcoin wallet address.


texts: Is there any way to move the Blockchain?

texts:
I'm using a solid state for my boot drive, I'd like to make sure the blockchain goes to my data drive, any way to acomplish this?

Edit: I am using easyminer and bitcoin-qt, it is about moving the blockchain. I looked for something similar. When you don't know what you're looking for it's hard to find answers about it.


texts: How is a multisig transaction transferred between multiple signers?

texts:
I'm trying to learn more about doing multisig transactions.
The examples I've seen show the signing of the transaction with 2-of-3, or 3-of-3, where the signatures are added, essentially, at the same time, and same place.
I'm wondering how does one, using rpc or cli, perform a multisig spend from physically separate machines?
How does a signer know that there is a transaction that he/she needs to sign?
Can a 2-of-3 transaction, that initially only contains 1 signature be broadcast, then updated by the 2nd or 3rd signatory?


texts: How can I generate addresses for all altcoins?

texts:
I want to develop my own exchange website having all the altcoins addresses. I am doing research from past few days and I came to know that I need a copy software client of all the altcoins, and then address can be generated by making rpc calls to these clients.

Do i need to setup these clients on my server (i.e VPS, AWS etc)?

If yes ? then what would be the best server configuration to handle the exchange and do I have to download these client one by one and then implement each ?

If no then how can I implement this ?

Currently I am running a bitcoin client on vps.


texts:
Almost a week ago I sent .05 BTC from my coinbase account to what I thought was my jaxx address, but I haven't received it.

The transaction (here) says that some of the output of the transaction was spent. Does that mean that I sent my BTC to the wrong address and the receiver spent it?


texts: In a mining pool, it says that there are active workers and active users. What is the difference between them? And does the block get divided per worker or per user?


texts:
What makes cross input signature aggregation complicated to implement? Other than for design space reasons why didn't it make it into BIP-Taproot? (Key aggregation within one input can be achieved with MuSig, MuSig2 etc but signatures cannot be aggregated across different inputs with BIP-Taproot.)
This questions was asked by Thorkil Vaerge on Twitter.


texts: Sending Bitcoin to Bitcoin Cash address. Restore without private key

texts:
I need help.

I use blocktrail.com for accept payment in my site by bitcoin cash.

Steps: 1. Generate bitcoin cash address 2. Sending bitcoin cash to generated address

One of customer sent bitcoin (BTC) to bitcoin cash address, and the address is available. Look at https://www.blocktrail.com/BTC/address/35HSWxagkcWxsEgDh3EWE6A1n3THyM1mqC/transactions

Question. How can I get these bitcoins?

I haven't got private key from bitcoin cash wallet, but I have got restore-file "Bitcoin Wallet Recovery Data Sheet". I guess that file can be use to restore only bitcoin cash wallet.

Any ideas?

Thanks


texts: What's a good resource explaining the best ways to buy Bitcoin (noob friendly)?

texts:
We have a slew of questions about specific regions ... but I couldn't find a general, concise, good resource on how to buy Bitcoins.

This article offers too many choices and isn't noob friendly.

I want to link to the answer from the Newbie Guide I'm making.

An answer to this question should not be a specific way to buy (it will get stale, Stack Exchange does not handle staleness issues very well), but rather an external resource that is maintained and up to date (and will likely remain so in the future). I suggest a new Wiki entry that is noob friendly.

Update: I've opened up a new wiki entry for this, you can help edit it.


texts: Why does bitcoind say "error: couldn't connect to server" for the first few minutes of boot-up?

texts:
After starting bitcoin from the command line, with:

./bitcoind -daemon

I immediately run the followup command:

./bitcoind getinfo

which gives me the following error:

  error: couldn't connect to server

This error lasts from a few seconds to a few minutes depending on the machine.

Two questions:

What is Bitcoin doing during this time, that causes this error (i.e. prevents the client from returning the results of getinfo)?
Are there any steps I can take that will minimize this start-up time?


texts:
I noticed something queer about cgminer, when I first started using it I got an ok amount of shares, but over time that number has been slowly dropping. it's the same difficulty,same temperature,but slightly less wu/m. it runs under the same conditions software  wise every day(i.e. no extra programs are running,Windows is not updating,etc) but yet it's still slowly dwindling away. not by huge chunks like suddenly stopping, but in general it's receiving less accepted shares(still 0 rejected shares, so it's not just failing at calculating them)
why is this happening, and is there anything I can do to help it?


texts: I transferred some ltc coins from gdx to binance. Binance shows that I have the transferred amount in my profile. But btc balance for trading is always shown as 0.000000. How much time will it take to reflect. I am trying to buy xrp and unable to buy because of that. what may be the issue?


texts: Lost my Bitcoin wallet and have only 11 out of 12 mnemonic seed phrase words. How can I get my Bitcoins?

texts:
I am new to the whole Bitcoin thing, and I am having my first attempt almost going sour. I lost where I created my wallet. I have my Bitcoin address and only 11 of my mnemonic seed phrase words (of 12). I attempted using a word I thought was it and then recovered a wallet on bread wallet, but after sync in, it was still zero balance for hours. I contacted the support group and they told me that I had probably made a mistake.

What can I do?


texts: Proving two public keys are derived from the same seed, without revealing the xpub and the path?

texts:
Let's think about the following scenario:

Key0 is derived from SEED at path m/44'/0'/0'/0/0
Key1 is derived from SEED at path m/44'/0'/0'/0/1

I am wondering if there's a way to prove that Key0 and Key1 share the same seed WITHOUT having to share the SEED or any Xpub along the way.
Basically I want to be able to prove two keys are somehow related without risking security (Where if you share an Xpub and one of its child private keys gets leaked, the entire sibling set is compromised).
It doesn't have to be exactly this, but my goal is to prove that two keys are related without sacrificing security, so if there are ways to do this, I would appreciate those solutions too.


texts: Create a 2-of-3 multisig raw transaction

texts:
I would like to create a Bitcoin transaction with a single input and a single 2-of-3 multisig output that pays 1 BTC to any 2 of the following 3 keys:
02983a79d2de8e504d00ddd2343b582acef7e17ed91b308ade8dff027a92e7716d, 03548ca1916957bc06dd1c6e3639ebf7b2c3c8b1715915433c1d37cab56fb26ef0, and
0218a240a599ba437cb1458966eb456d9f848e5bdef45ea0ee4ec31fc40aa4ffa8.

I just want a syntactically valid transaction, the reference to the UTXO does not have to exist.

Could you please guide me through the steps?


texts: Transactions are verified by miners. What happens when the last BTC has been mined?

texts: Let's say we're X years in the future and we the last bitcoin has been minted. Since you can no longer incentivize mining new nodes of the blockchain, how will transactions continue to be verified?


texts: What exactly does the scary option "Allow incoming connections" do in Bitcoin Core?

texts:
Software authors seem to enjoy consciously freaking me out by having vaguely or entirely uncommented options in their software with very ominous labels.
In Bitcoin Core's settings, it says "[X] Allow incoming connections", which has an entirely meaningless "elaborate description" on hover which just repeats what it already said with a couple more words: "Accept connections from outside."
What does this actually do? My first thought is that this enabled-by-default option somehow allows people from all over the world to connect to my computer and freely grab Bitcoins from my wallet.dat and look through and download files from my computer. Naturally, it doesn't mean that, but the way it's so vaguely described does not make me feel good, to put it that way.
My serious guess is that it has some kind of hard to understand technical explanation, but why is it an option to begin with if it's crucial for Bitcoin to function? Is there some privacy/security benefit to me unchecking it? Does leaving it on pose some sort of privacy/security threat*? Why is it an option?
(* Usually when you ask that kind of question, people will lie to you and claim that there is no security/privacy issue, when in fact there actually is. For example, PHP developers told me that there's nothing lost by keeping the expose_php and other configuration options on, but to me, there definitely is as it sneakily lets the world know that you use PHP and even which version. It seems that, whenever something is bad for users, but good for the authors of something, they claim that it doesn't pose a security/privacy threat.)
Would appreciate some clarification.


texts: I’ve been reading and researching bitcoin recently because I’m interested in the idea and would like to participate. My question is, since each bitcoin user is anonymous, if I bought something from someone else, how will they know where to send it? Also, if I’m transferring money to and from another person, how do I know it it going to the right person?


texts: Transaction hanged on 1 peer, did reset and now balance is 0 transaction is gone

texts:
I did an transaction to BTCe but it remained on 1 peer for a very long time.
I then reset my blockchain and transactions in Multibit but now the transaction is gone and my balance is 0. The adress on BTCe also says 0.

What can I do?


texts: Why is the data format for block height in coinbase scriptSigs inconsistent for heights 1-16?

texts:
BIP-34 claims that in coinbase transactions, the scriptSig should contain the block height. It says the format of this is "serialized CScript", i.e. a byte indicating the length of the number (n), and then n bytes in little-endian format.
This works if you look at e.g. the most recent block as of this writing—block 640037—whose coinbase scriptSig begins with these 4 bytes: 0x0325c409. 0x03 indicates the length, and then we have (0x25=37 * 256^0) + (0xc4=196 * 256^1) + (0x09=9 * 256^2), or 37 + 50176 + 589824 = 640037.
For obvious reasons mainnet and testnet will never need to encode heights 1-16 in their coinbase. But regtest nodes will. When I run a fresh regtest node (v0.19.1) and generate a couple blocks, I get coinbase scriptSigs that look like this:
height 1: 0x510101
height 2: 0x520101
...
height 16: 0x600101

Clearly it's not serialized CScript, at least in the format described in BIP-34. If it were, those first bytes would indicate data lengths of 81, 82, and 96 respectively, clearly ridiculous. The actual encodings of 1, 2, and 16 in serialized CScript are 0x0101, 0x0102, and 0x0110. It looks to me like the format is height+80 followed by 0x0101. And for some reason this only persists for the first 16 blocks, as 17's scriptSig is 0x01110101.
I tried looking through the bitcoin source code, but I don't write much C++ so it's hard to tell what's going on. No documentation—in the source (as far as I can tell) or the PR for BIP-34 or in the BIP itself seems to indicate that heights 1-16 would have a different format from every other height.
Why is this happening?


texts:
I'm looking for the historic circulated supply of Bitcoin.  I'm aware I can get the current supply by creating my own node.  But I need the supply at a given date.
Does anyone know of an API to get it.


texts: Help sending bitcoin to bitcoincash wallet

texts:
I've used an UPHOLD wallet to buy an AntMiner S9 from www.bitmain.com.

Bitmain provided a bitcoin cash address for payment.  However, by mistake, I sent bitcoin worth $1450 USD to their bitcoin cash wallet. Now, they have not confirmed the payment. And now I do not know what to do?  Where is my money?

Uphold gave me a BlockChain confirmation address and the transfer appears but as (not spent).  Neither bitmain.com nor Uphold has given me any reply.

I did this on Friday, November 17 and today, Monday, November 20, I have not received a response.

What should I do?  Can someone help me? I cannot afford to lose $1450 USD.


texts: Why are broadcast checkpoints considered bad?

texts:
warren, a LiteCoin dev, said of Peercoin:

Good Luck Removing PPC's Centralized Checkpoints
Regarding PPC... these amount to empty obfuscating defensive excuses.  Sure he wants to remove the broadcast checkpoints.  Novacoin's Balthasar made similar promises because he too knows that it is indefensible.  Unfortunately for PPC, in the age of ASIC's it will be impossible to keep a sha256d network stable without it, so I would be highly surprised if it is actually removed.

Why are broadcast checkpoints so indefensible? It would seem to make sense to have a protocol-level mechanism whereby the nodes agree not to go back past a certain number of blocks (say 10 or 20 blocks). What about the mechanism is flawed? It sounds like it's able to keep a network stable without requiring as much hashing power.


texts: Rules of the mining pools for mining software and weight blockchain Litecoin

texts:
What rules must a mining software fulfill in order for a pool to allow mining with the ?, example of a pool please.
How heavy is Liteco's chain of blocks at this moment or where can I consult it?


texts:
I was exploring recent crypto news and it seems that i don't get a point in the stable coins trading.
Is there any logical reason to trade (with leverage) stable coins over fiat?


texts: If I wanted to imprint the blockchain data on a database, with the purpose of performing complex or just different than the RPC-based queries, how would I do it? Would I have to go for a relational database or a NoSQL one? Eventually the database would be filled with hundreds of millions of records, which databases would perform well (respond quickly) to these gigantic numbers?


texts: the bitcoind daemon doesn't respond to commands

texts:
For some reason, the daemon doesn't accept commands neither RPC, nor command-line.
I'm running the prebuild 64 version of the bitcoind. It already downloaded all blocks etc and as is happyly running in the background, however it doesn't allow any commands to be sent. For example:

./bitcoind getinfo
error: couldn't connect to server

I tried with a config file having only the rpc user and pass, then I extended it with different params, and of course have restarted the daemon each time. Still - no luck.

The debug.log is not telling anything either. It just dumps the normal intensive communication, like…

 2013-12-07 22:01:40 received getdata for: tx
 593f4528895f75bcd3df12fb09eedb7e5e6659a7a8a999d7e127eb131afde417)

but no trace from my attempts to call a simple command.

I tried to google the problem without luck.


texts: Error transferring bitcoins to another wallet

texts:
I'm a beginner in the bitcoin context.
I opened an account online with Bitpanda and I have a wallet on my computer with Bitcoin core.
I bought some bitcoins for testing and I want to move them into my Bitcoin core wallet.
But everytime that I try the transfer, bitpanda says me that my internal wallet does not have enough bitcoin but I did not specified any amount of bitcoins to transfer.
From what this may depend?


texts:
I sent 1500 from my wallet address last 2weeks transaction faild to confirm transaction id
1624600252fd611c8d07ae4f6a7922850ea52014d93265fa7340979e8fd55647


texts:
My config file is similar to this:

testnet=1
blocksonly=1
rpcport=5000
server=1
listen=0
prune=1000
dbcache=16000
rpcallowip=0.0.0.0/0
rpcuser=someuser
rpcpassword=somepass

I have started the node sync in testnet mode and I tried to check the status by using the command

$ tail -f testnet3/debug.log

Ouput: 2018-04-08 04:09:51 Potential stale tip detected, will try using extra outbound peer (last tip update: 46620 seconds ago)
2018-04-08 04:20:21 Potential stale tip detected, will try using extra outbound peer (last tip update: 47250 seconds ago)
2018-04-08 04:30:51 Potential stale tip detected, will try using extra outbound peer (last tip update: 47880 seconds ago)
2018-04-08 04:41:21 Potential stale tip detected, will try using extra outbound peer (last tip update: 48510 seconds ago)
2018-04-08 04:51:51 Potential stale tip detected, will try using extra outbound peer (last tip update: 49140 seconds ago)
2018-04-08 05:02:21 Potential stale tip detected, will try using extra outbound peer (last tip update: 49770 seconds ago)
2018-04-08 05:12:51 Potential stale tip detected, will try using extra outbound peer (last tip update: 50400 seconds ago)
2018-04-08 05:23:21 Potential stale tip detected, will try using extra outbound peer (last tip update: 51030 seconds ago)
2018-04-08 05:33:51 Potential stale tip detected, will try using extra outbound peer (last tip update: 51660 seconds ago)
2018-04-08 05:44:21 Potential stale tip detected, will try using extra outbound peer (last tip update: 52290 seconds ago)

...and keep on getting the same

Again I tried this command to see the peers info

$ bitcoin-cli getpeerinfo
output:
[
]

It means there are no peers, so I want to know what is wrong.

The syncing is happening from more than 13 hours, but still headers and blocks are 0 only.

$ bitcoin-cli getblockchaininfo
{
  "chain": "test",
  "blocks": 0,
  "headers": 0,
  "bestblockhash": "000000000xxxxxxxxxx",
  "difficulty": 1,
  "mediantime": 1296688602,
  "verificationprogress": 5.667000646249453e-08,
  "initialblockdownload": true,
  "chainwork": "0000000000000000000000000000000000000000000000000000000100010001",
.......


texts: I am new and using multibit 0.5.14. I have received 2 bitcoins in one transaction, and 0.005 in another. However, after over an hour they are still not spendable. I checked the status and it says "seen by 4 peers Pending/Unconfirmed. When I check on blockchain.info, there are 17 confirmations for that block. How do I know if something has gone wrong? Is there something else I should do to make my bitcoin 'spendable' or do i just have to wait it out longer?


texts: What can you do in case the number of blocks becomes greater than the maximal number of files that can be stored in a file system (ext4, FAT, etc.)?

texts:
In this case (which has actually happened to me), if I sync all blocks, they fill up the whole file system table of the volume.

What is the best way to solve it? Using one directory that is split over multiple volumes? How can you achieve that? Using symlinks or junctions?

There is also a limit of files per directory. This means that the entire copy of the blockchain database should be split over a double amount of directories each time it reaches this threshold (like dynamic hashing).

I tried to search for solutions that address these issues, but I simply couldn't find anything, like nobody has ever thought about these situations.


texts: Which mobile clients allow payments using Near Field Communications (NFC)?

texts: Which Bitcoin apps (or mobile-enabled websites) support the ability to pay using Near Field Communications (NFC)?


texts: bitcoind: How to find the block from a TXID?

texts:
I'm using bitcoin-cli. I have a TXID, and I'd like to find which block it is in. Either the block hash or block count would be fine. What's the best way to do this?

I've tried using gettransaction < txid> and going from there, but I get this error:

error: {"code":-5,"message":"Invalid or non-wallet transaction id"}


texts: Where in the Bitcoin Cash code is the retargetting period defined?

texts: I'm specifically looking for the difficulty retargetting period of Bitcoin Cash, but since it is a fork of Core it should be the same code.


texts: generating a private key for a blockchain wallet

texts:
I hired a broker to make forex and crypto profits for me.  They did and put it in my broker account.  the only method to get the profit out was to put it in a blockchain wallet.  After they did this, they told me to get the private key from them to withdraw the profit was to pay a very expensive fee.  I do not have that money at the present time or in the near future.  Is there an easy way to generate my own private key from my blockchain app on my Samsung to withdraw the money and put it in my bank account? I feel it is my bitcoin, why can't I withdraw it without buying a private key from them? I would like to have someone
walk me through a simple process to generate my own private key.  I read online that if you do not do it right, you can lose that bitcoin forever.  I don't want to do that.  Let me know if you can help me with this problem.  Thanks.


texts: Is Bitcoin Core required for wallet projects?

texts:
My team wants to create a cryptocurrency service provider platform to Sell/Buy BTC and something else in form of web/mobile app. It's about one month that I have been studying different articles about its requirements. The crucial things we need in this project are:
1- Creating wallet for customers
2- Let customers to send/receive BTC from/to their wallets

I found both API providers, and something else like Bitcoin Core, Bitcoind, etc.
We prefer to build our own platform and avoid depending on 3rd party vendors.  May you tell me do we need Bitcoin Core to do our project needs? If your answer is yes, can we install it on a server and access to it remotely via API?


texts: Determining sender/receiver address in transaction

texts:
Suppose that I were given a wallet address, i can retrieve all the transactions for the particular address.

My question is:

1) Assuming the wallet address is sender, how could it determine the receiver of the address? Vice versa if the wallet address is receiver, how could it determine the sender address from transaction detail? I have seen few transactions but couldn't think a full proof solution to it.

Taking this transaction as example, how could i know which address actually initiate send bitcoin transaction to the wallet address mz95VxTekXHVZCPVjtK7pF2dMa7yF8QMkM.

2) Using the same transaction id, how could i know the miner fee paid by a particular sender? I know that the both sender address pay a total of 0.000035 BTC fee, but how do I know how much each of them paid initially (the miner fee each of them set before sending transaction)?


texts: Solve problems using bitcoin smart contracts

texts:
Been trying to ask this to few people on different platforms but nothing was helpful so trying here and will keep trying because I don't even know what else can I do to learn more and contribute.
What will be the best way or resources to refer if someone has an idea and want to implement it using bitcoin smart contracts?
For example: If I want to create a decentralized insurance product which might even need external data so won't be completely decentralized but trust minimized, non custodial, non kyc and better than present solutions. Users will have to regularly pay some amount which should be locked in some multisig setup and used in a way that it gets interest so maybe provide liquidity in joinmarket, create a lending/borrowing thing using discreet log contracts or something else, these profits can be used to cover life and release amounts after verification on claims
How would I approach solving this problem using bitcoin?
What are best resources to learn more about discreet log contracts, it's examples?


texts: What is the algorithm of block selection using Target Difficulty?

texts:
Suppose below is target difficulty:

0x0000CDEF0A000000000000000000000000000000000000000000000000000000

So result value must lower than target to select block.

So, If Miner 'A' found:

0x000000000000000000000000076898778ABEFDC34798734590349843BDCAE854

Will miner 'A' can satisfy target difficulty or not?

And if not then please tell me the reason.

Thanks


texts: What are the key features of eMunie, a crypto-currency that's not a Bitcoin fork?

texts:
https://bitcointalk.org/index.php?topic=220530.0

The ANN is not super clear. From what I understand, the supposed key features are:

Immunity to 51% attack
"protection against hoarding" ??? (someone please explain this)
A built-in messaging system

Can someone explain/elaborate?

  So whats different

  eMunie has similarities to current crypto-currencies by way of a
  public ledger, blocks and transactions.  These however, are where the
  similarities end and innovation for a better system comes into action.

  The network is composed of clients, seeders and hatchers, the
  functions of which will be explained in this announcement.  Any node
  can take task in one, or any combination of these roles dependent on
  the users wishes.

  The network is resiliant to any type of "51%" attack, as the models
  required to perform such an attack are not present.

  Currency generation within the network is a collaborative effort, and
  created currency is distributed according to a set of requirements.
  This distribution should help to ward against hoarding, which can
  further lead to volatility of the currency.

  The network performs extensive verification of itself, more so than
  the BitCoin algorithms, to ensure that all participants are honest
  nodes and for additional security overall.

  A secure, anonymous peer 2 peer messaging system is built into the
  network, allowing secure, untraceable communications between 2 or more
  parties.


texts: Why isn't Bitcoin using public key extraction from signature to reduce the blockchain size?

texts: Why doesn't Bitcoin use public key recovering from the signature in order to reduce the Blockchain size? This would save 32 bytes per transaction input.


texts: Is there incentive for those who run lightning nodes?

texts: This is likely very much a noob question, but I would like to know if there are fees or incentives for those who are running a lightning node? Of course, other than having access to lightning network?


texts: HTLC (Hash Time Lock Contract) using bitcoin-qt

texts:
Is it possible to manually create a HTLC using the bitcoin-qt command line?

I know how to manually creating createrawtransaction/sendrawtransaction using the bitcoin-qt clients command line, and wanted to know how to manually create a HTLC.

When  I say "manually", I mean, really getting your hands dirty, like using notepad to construct the contract, putting the values into bitcoin-cli, to convert it into a hash, ready for it to be sent using sendrawtransaction.


texts: Bitcoin transaction with dust output stuck

texts:
I made this transaction more than 24 hours ago, and it still has no confirmations at all.

What should I do? This transaction was created by the mobile Blockchain.info wallet. At the time, it didn't warn me that transaction was problematic. However, I later noticed that one of the outputs of transaction is dust, using Blockchain.info's block explorer.

Any suggestions how to solve this issue?


texts: Does the Taproot update benefit all bitcoin users? or is it for a selective amount of people

texts: I came across a blog post where it mentions that the taproot update is promised to speed up BTC transactions, lower their fees, etc. but does this mean that literally, anyone sending or receiving BTC will benefit from it? will it require special software to operate?


texts: Where can I find some guidelines on how to program a merged mining transaction?

texts: In answer to question "How does merged mining work?", we can read that in order to merged mine, we need to create a Bitcoin transaction containing a Namecoin block hash and put it on the tip of the merkle tree. Where can one find some guidelines or specification on how to create such a transaction?


texts: Encrypting Bitcoin private keys instead of printing out paper

texts:
I follow the procedure of making a cold storage wallet: downloaded copy of bitaddress.org using an off-line computer booted with Ubuntu from CD.

Instead of printing out the private keys and corresponding addresses for my bitcoin, I simply use a JavaScript file (http://prgomez.com/ursa/) to encrypt the private key, while I am using Ubuntu. I then keep together the address and encrypted bitcoin private key safely so I don’t lose it, but with no need for special security. All I need to keep in paper is my 80 bit plus password for the encryption of the key.

Logically, this seems to me safe, though I have so far only entrusted small sums of money to this procedure.

Is it safe?


texts: Monitor all transactions on bitcoin network - API

texts:
I am searching for a solution to monitor all bitcoin transactions (or for first ties at least for addresses inside my bitcoin client).

I found http://blockchain.info/api_websocket is this really reliable? What happens if my client is offline?

Is perhaps the better way to run a bc-client an use a poll - every second?


texts: Possible to do recurring payments with Bitcoin?

texts:
I'm a developer and using the Coinbase Ruby API to attempt to build a Coinbase application.  I'm still coming to grips with how it all works.  My question is, is it possible to set up recurring payments with Bitcoin?  If so, how does that work?

I would prefer not to lean on a solution where I'm waiting for the customer to submit a payment every month, but for regular one-time payments, it was mentioned to me on this forum that the only way to accept them is to give the customer an address and hope they submit a payment.


texts: Difference between block hash and transaction hash in bitcoin-core

texts:
Is there a logic based on which one can determine if a given 32-bit hash corresponds to a transaction or a block without enquiring a bitcoin-client?

In other words, how do I differentiate or validate a given 32-bit hash as a transaction or block identifier?

I understand, that a valid block hash is restricted by the difficulty limits (that offer lower and upper bounds). Is there something similar to validate a transaction hash?
Reference: How is difficulty stored in blocks?


texts: "BitCoin-QT" Core Upgrade - PRIOR Steps?

texts:
I plan an upgrade of an old "BitCoin-QT" Core client wallet from 'V0.7 2-beta' to the latest Bitcoin Core 0.15 (Oct 2017).

I've got good instruction on the upgrade path - but my questions is:

Besides backing up my ‘wallet.dat’ (in case something goes wrong in the upgrade) - is there anything ELSE I should consider in this big Upgrade leap ? Thanks


texts: 19 out of 24 words of BIP39 passphrase (brute-force last 5?)

texts:
I have managed to lose 5 words of my 24 word Ledger Nano S recovery phrase. I have words 1-19 but I am missing words 20-24. I have significant holdings on the wallet so would very much like to recover it if possible. The passphrase is a BIP39 mnemonic (see https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki). I have the bitcoin and ethereum public addresses for this mnemonic. I am wondering if it's feasible to brute force the passphrase.

Each word is 11 bits (2^11 = 2048 possible words). The last (24th) word of the passphrase is of the following form [3 random bits][8 bit checksum]. Therefore I only have to check 2^(55 - 8) = 2^47 = 1.4x10^14 combinations. I would have to compute SHA-512-HMAC with an iteration count of 2048. As far as I understand, that means I'd have to compute 1.4*10^14 * 2048 = 2.87*10^17 hashes in total.

Is there any hardware out there designed for this? I am aware of ASICs that compute sha-256 hashes but not sha-512 hashes. Perhaps I could tweak one to work with sha-512 since they are very similar.

Assuming a fairly typical ASIC hashrate of 1TH/s (10^12 hashes per second), I could exhaust the search space in 2.87*10^5 = 287000 seconds = 3.3 days. I'd probably get there sooner, of course (expected 1.65 days). Time is not something I am worried about. Even if I have to wait months, I don't mind - so if I can get 10GH/s at a reasonable price, that would be great.

I would really appreciate any help/information you could provide to help me out and make sure I haven't missed anything. I could also use GPUs for this (I calculate I can run them at roughly $1/10TH - so it would cost me $28.7k to exhaust the search space, which I will do if there are no cheaper options).

Many thanks, James


texts:
In bitcoin wallet that support bip39 mnemonic code, is there a way to get the 12/24 words from the seed generated by them?
Or the translation is one-way only (from words to seed)?


texts: Bitconnect balance not showing on my wallet

texts:
I sent from Bitconnect platform to my QT wallet and still showing 0.00 BCC, even though the transactions is confirmed and sent since yesterday. Could anyone help me with this? This is all the info I have for the transaction in case it helps.

Bitconnect Wallet Address: 8QDhQ1vWkuR4L5h7E6vKm1tGVmsFzWUyW3
Transaction: 58066e3767dbc02c219d24ab2995723f88f552889c0e60385f607487c10b0acc
Block: 289640
Day/Time: 1/17/2018 14:06
Amount: 3.35790826


texts:
Conceptually, even if the network doesn't have any "real" transactions, the very act of mining creates new transactions to be mined. Self fulfilling prophecy.

So, what is the real purpose of mining if the network is virtually dead? I suppose at that point the currency would be worth nothing and no one would mine it.

This is a bit of a philosophical question :-)

Likewise, is this similar to how pre-mining works? Where the creators mine the coin ahead of it's release?


texts: who is sending all the 120-140 satoshi/byte transactions?

texts:
In the last few weeks, the mempool size has grown significantly. You can see with a mempool fee viewer such as this one that overwhelmingly, transactions are growing at the 120-140 satoshis/byte fee range.

Why would this particular level grow so much faster than any other level? Is there any activity that is more likely to be in these transactions? (like sending money to exchanges, activity from certain wallets, certain blockchain services, etc...?)


texts: Do physical bitcoins or altcoins actually carry value?

texts:
This question establishes that there are physical bitcoins that can be bought and I recently just bought a physical Dogecoin as a trinket but I can't help but wonder if there's a solid value related to these coins.

Bitcoins can be found for 1, 10, and 25 BTC and I just bought my Dogecoin coin for 10 USD (18947 Doge after shipping and handling). If someone were to hold onto these coins for years and attempt to sell later on, what would they be worth? Is a 1 BTC coin always worth 1 BTC or, like a collectible, is it only guaranteed to be worth what somebody will pay for it?

I know it's not officially backed or anything, but is it reasonable to think that if I bought it for 1 BTC that somebody else would pay me 1 BTC for it later even if the value of BTC changes?


texts:
Regarding the serious bug found (CVE-2018-17144) I am note sure if I understand the full scope of it correctly.

As far as I understand, any block containing a double-spend of a transaction output that was spend in any block prior to the mined one would not have been catched as an invalid block?

If that is the case I wonder if the test suite of bitcoin core does not have a test case implemented for this situation?


texts: I'm wondering if there is a flag that allows running bitcoind without using an obfuscation key for the chainstate. I haven't been able to find it.


texts:
I have mtgox account, and once I changed my android software i forgot to link another google authenticator, so to access mtgox I had to unlink it of OTP.That wwas two weeks ago
Last week, i still didn't linked new OTP, and I had my BTC funds stolen and widthdrawed to another account. I know that transactions canot be undone by can I do anything to find where are my BTCs?

Regards


texts: How to verify a signed message by bitcoin core?

texts:
I want to verify, in Java, a signature produced with bitcoin core's signmessagewithprivkey (equivalent to the verifymessage). I noticed a bitcoinj method similar to the bitcoin core's verifymessage - org.bitcoinj.core.ECKey.verify. What follows is my implementation attempt and its test.

For testing I will generate a signature and check it in bitcoin core:

>bitcoin-cli signmessagewithprivkey $(bitcoin-cli dumpprivkey 1CwKH9PQPkFPjQagEv483FUM5ngk57L3Pp) ""
H2wp/+5N2+OQwP6a5GFRbt8S+EfML1Szx4uhWPfiO0e/QcY2rZQOkLOR+unknNl4NgDWBacRRXOLjr+m53V0xic=
> bitcoin-cli verifymessage "1CwKH9PQPkFPjQagEv483FUM5ngk57L3Pp" "H2wp/+5N2+OQwP6a5GFRbt8S+EfML1Szx4uhWPfiO0e/QcY2rZQOkLOR+unknNl4NgDWBacRRXOLjr+m53V0xic=" ""
true

So, signing an empty message with the RPC using the address 1CwKH9PQPkFPjQagEv483FUM5ngk57L3Pp (public key: 021c3be5fb7820c56d881ea2d02a906d87540ec8888bbe819b7abd2e39f6f6e512), produces the signature H2wp/+5N2+OQwP6a5GFRbt8S+EfML1Szx4uhWPfiO0e/QcY2rZQOkLOR+unknNl4NgDWBacRRXOLjr+m53V0xic=.

My Java implementation attempt:

import org.apache.commons.codec.binary.Hex;
import org.bitcoinj.core.ECKey;
import org.bitcoinj.core.Sha256Hash;
import java.math.BigInteger;
import java.util.Base64;

public class Notebook {

    public static BigInteger[] ParseSig(byte[] sigBytes, int sigOff) {

        BigInteger r = new BigInteger( 1 ,sigBytes, sigOff, 32);
        BigInteger s = new BigInteger( 1, sigBytes, sigOff + 32, 32);
        return new BigInteger[] { r, s };
    }

    public static void main(String[] args) throws Exception{

        // Signature
        String signatureString = "H2wp/+5N2+OQwP6a5GFRbt8S+EfML1Szx4uhWPfiO0e/QcY2rZQOkLOR+unknNl4NgDWBacRRXOLjr+m53V0xic=";
        byte[] signatureBytes = Base64.getDecoder().decode(signatureString);
        BigInteger[] signatureRandS = ParseSig(signatureBytes, 1);
        ECKey.ECDSASignature signature = new ECKey.ECDSASignature(signatureRandS[0], signatureRandS[1]);

        // Public key
        String pubKeyString = "021c3be5fb7820c56d881ea2d02a906d87540ec8888bbe819b7abd2e39f6f6e512";
        byte[] decodedPubKeyString = Hex.decodeHex(pubKeyString.toCharArray());
        ECKey publicKey = ECKey.fromPublicOnly(decodedPubKeyString);

        // Message
        String message = "Bitcoin Signed Message:\n";
        Sha256Hash messageHash = Sha256Hash.of(message.getBytes());
        Sha256Hash messageDoubleHash = Sha256Hash.of(messageHash.getBytes());

        // Test
        boolean result = publicKey.verify(messageDoubleHash, signature);
        System.out.println("Result: " + result);
    }
}

Notice that I used the salt Bitcoin Signed Message:\n before hashing the message - this is done by signmessagewithprivkey as shown here and here. The problem is the above implementation doesn't pass my test and I don't know why...

EDIT:

Thanks to Septem151 I was able to fix this. The code passes the test, if the message section is replaced with:

        // Message
        String message = "Bitcoin Signed Message:\n";
        byte[] messageBytesEncoded = new byte[message.getBytes().length + 2];
        messageBytesEncoded[0] = 0x18;
        messageBytesEncoded[messageBytesEncoded.length - 1] = 0x00;
        for(int i=1; i <= message.getBytes().length; i++) messageBytesEncoded[i] = message.getBytes()[i-1];

        Sha256Hash messageHash = Sha256Hash.of(messageBytesEncoded);
        Sha256Hash messageDoubleHash = Sha256Hash.of(messageHash.getBytes());


texts: I would like to introduce a number of people that are not necessarily tech-savvy to Bitcoin and instruct them how to make their first payments. Is there some "Bitcoin for dummies" guide that I could be referencing that would be understandable to anyone capable of using a computer and the internet payments?


texts: What algorithm do bitcoin miners use to choose which tx to include in their block?

texts:
I understand it's in the miner's best interest to receive as many fees as possible for his hopefully-accepted block, hence it should include the most rewarding (fee / size) txs - up to the 1MB limit.

However, what algorithm do the miners use? It seems like a knapsack problem, which is NP-Hard, so I doubt miners actually go for the optimal solution.

Thanks!


texts: Is it possible to share blockchain data between multiple nodes?

texts:
I'm planning to create a Raspberry Pi Cluster in order to run several bitcoin nodes. Can I share parts of the ~/.bitcoin/ folder in order to not have to store the entire hundreds of GB for each of the nodes? My idea would be that one of the nodes has an external hard drive with the bulk data and the others make use of it over nfs or smb.

Any ideas or even experience on this?