texts: how to prevent losses after a hard or soft fork

texts: i learned about hard and soft forks from this question; now i have a basic understanding about forks; but the answers of that question did not say what happens to transactions on the stale chain; if i understand correctly those transactions are simply given up? but this looks like people would lose their money if they received payments on the stale chain; how does the bitcoin protocol protect them in this case? (there is a timer for confirmation of transactions but i am still not sure how it is being used and why it is adequate;)


texts: Bitcoind crashes directly after starting

texts:
I'm am trying to solo mine. My first problem is when I try to launch bitcoin client as server with guiminer I get this error

Invalid -rpcallowip subnet specifications.* valid are a single ip.

I looked around and it seems that I need to open bitcoind and change my rpcallowip from what I understand.

My problem then is, when I try to open bitcoind, it pops up for 1 second then crashes. I have tried to run it as admin, I have downloaded a new wallet, but I couldn't get it to work.

From what I have seen my guess is it looks like rpcallowip=192.168.0.* I have seen I need to change it to rpcallowip=192.168.0.1/24. The problem is I don't know where to change it. Also I don't know if this is even the problem. I am trying to take this one step at a time. .

I thought it was in bitcoin-di. And like I was saying every time I try to load it, it crashes.

My goal is to get guiminer to solo farm with bitcoin core as my wallet. I thought it would be an easy process.

I'm on windows 8.1 with bitcoin core v0.10.2. Using guiminer. I set up with slosh pool and got that to work. My gpu is not strong enough to do any good tho so I figured I would give a shot with solo.

I'm not sure of I'm way off. Where so I go to change it?

Thank you for the response.


texts: What happens when NameCoins stop being generated?

texts: When Bitcoins stop being generated it won't be a problem: prices can gradually be lower. Namecoins, however, have a more-or-less set price, which is the domain register price. If Namecoins stop being generated, but people of course still want to register domains, what happens?


texts: In the sourcecode, what does this line mean that recovers the key from the signature?

texts:
I understand that the public key (Q) can be extracted from a signature (r,s), but I'm having trouble understanding this line:

if (!key.Recover(hash, &vchSig[1], (vchSig[0] - 27) & ~4))

The third variable is called "rec" and must 0 through 3.

What is the purpose of this parameter (3rd one)?
Why is the signature starting a byte1 and not [0]?  Perhaps I'm not properly understanding "where" r and s is located in the Bitcoin signature.

By any chance is the signature format encapsulated in any standard? PKCS..? etc.


texts:
Under the bitcoin Protocol rules here:
https://en.bitcoin.it/wiki/Protocol_rules#Transactions
in the "block" messages section
There is the pseudo-algorithm for validating a given block.
On Point 16-2 It says:
"Reject if coinbase value > sum of block creation fee and transaction fees"
If we keep it simple,

I know that the block creation fee is calculated using 64 bit integer operations (in satoshis) as:
(50 * 100000000) >> (height / 210000)

And I also know that transaction fees are defined as:
the sum of input values minus sum of output values for a given transaction.

So the overall transaction fees on a block would be the total sum of all transaction fees in that block.
But how do I 'calculate' in pseudo-words, the coinbase value and what is it referring to?
I seem to not understand something here...
Thanks in advance


texts: What is the rationale for the Lightning network's path length limit (20 hops)?

texts:
A sender in the Lightning network can choose a path with up to 20 intermediaries (BOLT4).

Tor is another network that uses onion routing for anonymity. However, in Tor all paths have 3 intermediaries, and longer paths are explicitly advised against (source 1, source 2). The sources make a point that attacks mostly rely on compromising the first and the last nodes, and increasing the number of nodes in between doesn't improve anonymity, but increases latency.

Do similar arguments apply to Lightning (maybe for path of slightly higher lengths but still under 20 hops)? Where does the number 20 come from? Would it be a good idea to decrease it?


texts: Do miners receive a reward when solving the hash for the next block or when validating the block, or both?

texts:
Let's say I want to make a transaction to my friend Bob.

When I send 10 BTC to Bob, a transaction is signed with my signature and sent to the network.

What happens next?

Do miners check if this transaction is valid (check if I have enough funds)?

If they do, do they receive a reward for this?

When the transaction is considered valid it gets sent to a block with other transactions.

This block is then mined (miners try to find the correct hash from the previous block by solving the problem) and once a miner solves this first, he sends the block to the blockchain.

My question is, if the block is invalid and gets sent to the blockchain, why other miners check if said block is valid?

Does the first miner that "solved" the block wrong get a reward?

What if the block that was solved by this miner validated correctly and was sent to the blockchain.

Why would other miners check if it's correct when the miner already received the reward.

What do they get from checking the solved block if they are already working on the next one?

I'm sorry for the long post but this part confuses me quite a bit.
Thank you


texts: Is it correct to say that continuous transactions are on different blocks most of the time?

texts:
I'm new to the idea of bitcoin and I'm taking an introduction course about it. Given the following picture from the original bitcoin paper, is it correct to say that continuous transactions are on different blocks most of the time?
If this is true, after a miner receive a broadcast of some transaction, how did he find those predecessor transactions for these to be processed transactions, so he can form his own block containing these transactions? Does he have to browse through all the transactions in the world to find these "predecessors"?


texts: What standard is used for the ECDSA to verify transactions?

texts:
Bitcoin used Elliptic Curve Digital Signature Algorithm. (see here). I'm wondering what standard is actually used for this Algorithm: which curve? which prime? Can anybody give me a reference? (Wiki gives this, is this the standard that the ECDSA in Bitcoin?) Anywhere I can find an update on this?

Edit: A bunch of curves are given in page 87 of this. Is bitcoin using one of these?


texts: (CHECKSIG) Why is the ScriptPubKey from tx-inputs part of the signature?

texts:
I was checking OP_CHECKSIG today and see that the signature of a transaction will be computed from the transaction but copying the ScriptPubKey from the transaction referenced as input into the SigKey of the new transaction.

I guess this has something to do with tx malleability, but I cannot see in what case this would really help? The tx-inputs already reference IDs that can be changed implying malleability.

It would only make sense to include the inputs ScriptPubKeys if it would be possible to keep an ID while changing its ScriptPubKey (which is not possible), or am I missing something?

I am refering to this graphic Step 7 + 8:
https://en.bitcoin.it/w/images/en/7/70/Bitcoin_OpCheckSig_InDetail.png


texts: Does an Invalid Transaction persist in the mempool?

texts:
My basic understanding is that a transaction will continue to exist in the MemPool until it can be completed, (or eventually gets evicted due to the size of the MemPool).

To me, this leads to a strange situation:

A Wallet tries to spend more BTC than it current has
Miners reject that transaction (or more properly, fail to confirm it). But the transaction remains in the mempool.
At some much later point, the Wallet gets more value.
The previously rejected transaction can suddenly be confirmed.

This is roughly equivalent to bouncing a check with your bank, and then having the check clear days, weeks, or months later when you eventually get the money!

Is this actually how BTC works?  Or is there point where a transaction can be officially and completely rejected, just as at it can be confirmed?


texts: I am new to this Bitcoin thing but I have a closing next week and will have $50K that I am looking to wire to someone to purchase Bitcoin.  Where is the best place to do this?  What about one that does not require ID as well?  Thank you for your help


texts:
I don't understand if each full node has different mempool inside.

With RPC command getblocktemplate I can Get the information about candidate block.
I can Find all transaction verified but unconfirmed
And I can find even bits and target, the value for mining.

My mempool is different from another node?
I have to Update my mempool before build candidate block ?


texts: Is ethereum related to bitcoin? does any one know weather they are related or not.


texts: bitcoin:uri for sending payments to multiple addresses

texts:
Lets say I want a donate bitcoin button/QR code to send to multiple recipients in different ratios.

As in send 50% to wallet 1.
Send 25% to wallet 2.
Send 25% to wallet 3.

Is there any way to do this in a single transaction, IE, make a single bitcoin:uri to pay multiple people?

Thanks in advance.


texts: If my phone is powered off will i still receive my bitcoin

texts: I sent someone Bitcoin but they said they didn't receive it because their phone is powered off but I got a complete transaction confirmation


texts: How can I add an old Bitcoin wallet address from Bitcoin Core to MultiBit HD?

texts: I have a wallet with Bitcoin Core.  I have used that address on various sites to receive payments from them.  I want to add that address to my account on my MultiBit HD program so it will just carry over to the new program but I cannot seem to figure out how to do it.  Please bear with me I am fairly new to all of this and I am still getting familiar with how things work.  Thank you in advance for any help you can offer


texts:
Does anyone know how to decrypt on a mac? I used openssl enc -aes-256-cbc -md md5 -a -in /Users/adriangonzalez/Desktop/bitcoin-wallet-backup-2019-06-26-22-20 -out ~/Desktop/file.txt, but the resulting file does not show mnemonic 12 words.

I'm using Bitcoin Wallet for Android.


texts:
i have created watch wallet
Wallet wallet = Wallet.fromWatchingKeyB58(params, tPub, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
How can i link this with block chain
i am using WalletAppKit class

kit = new WalletAppKit(params, walletFile, APP_NAME);
kit.startAsync(); kit.awaitRunning();

after that i add wallet in PeerGroup kit.peerGroup().addWallet(wallet)
after that i print address of a wallet System.out.println(kit.wallet().currentReceiveAddress());
but this address and System.out.println(wallet.currentReceiveAddress());
this is not same.
i am using bitcoinj for this, i have sent multiple transaction on wallet.currentReceiveAddress()
but did not receive any of them, i don't know what i am doing wrong here, kindly help!


texts:
I think I understand multisig wallets: X out of Y signatures are required for a transaction to be made.

My question is: is there such a thing as a multisig wallet where any ONE of the allowed signatures can complete the transaction? So we have a ring of 5 people, and any one of the five can take any action with their unique on the wallet, essentially sharing it.


texts: Unable to broadcast native P2WPKH (SegWit) TX; malformed, but how?

texts:
I'm trying to add SegWit functionality to my app but am running into trouble building my transaction. I've read BIP143 so many times I virtually have it memorized, and I've followed it to the letter. But for whatever reason my TX is being rejected.

Here's how my transaction is structured:

input #1
AF83F3F0EA5D11C3824C336250325D7597F891384282F73362AF0D7A70A94713, index=1, amount = 1000000

This is a P2WPKH input corresponding to address bc1qe9p5qmlqwhaxtmjkrdfp8lyswyww8ur5pzkg3c

input #2:
E85B128C57AD00E7439D25E1ED1BA18E74886D45E45DEE7F4C196566946D0BC9, index=1, amount = 3571510

This is a standard P2PKH input

output #1:
bc1q5ss6h56zsv56q3w2axwwv2v9zqgajtr5ud5llr, amount = 1071200

output #2:
bc1qj2r7lu7g3tccv4zsg54c08ptgescaxt8u8tfvs, amount = 3471510

I've built my transaction according to the specifications presented in BIP143. Here's the transaction in hex form:

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

Now, if you take that transaction and plug it into a deocder like the one here, you'll see that everything is parsed properly. Everything looks good. Still, everyone rejects my transaction. For example:

Pushing through Blockchain.info or using the raw transaction pusher in Electrum yield the following error:

Validation Error: BitcoindException(super=com.neemre.btcdcli4j.core.BitcoindException: Error #-26: 64: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation), code=-26)

Pushing through BlockCypher yields a different error:

af83f3f0ea5d11c3824c336250325d7597f891384282f73362af0d7a70a94713 at 1: Script was NOT verified successfully..

The errors are a bit cryptic but that second error seems to be pointing the finger at my first P2WPKH input. It says the script wasn't verified. The thing is though, P2WPKH inputs don't have a SigScript. By definition, the SigScript is supposed to be empty. So presumably it's referring to my witness which, as you can see if you used the decoder, contains two items: a signature and a public key.

I swear I've checked that signature 100 times. It verifies. Perhaps what I'm signing (the sighash, also described in BIP143) was improperly constructed? But again, I've looked it over and I'm following the 10 step sighash generation procedure precisely.

which brings me back to the error generated by Electrum:

Error #-26: 64: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation), code=-26)

I haven't a clue was this means. The only reference to non-mandatory flags that I can find is here and code '64' seems to refer to a constant named SCRIPT_VERIFY_MINIMAL data. There's also code "-26" in the error message. I haven't a clue what that refers to.

I feel like this must be signature related somehow but like I said, the signature verifies just fine. I've made sure that the sig has a "low S value," which has caused me some problems in the past. Not sure where else to look. I'm totally stumped.

Any ideas?

UPDATE:

I figured out the source of my error. See comment below. Sysops can delete this question since it's now resolved.


texts: How to generate a Bitcoin Private Key Checksum

texts:
I want to understand how a bitcoin private key is made up.

Looking at this graphical generator
https://royalforkblog.github.io/2014/08/11/graphical-address-generator/#hello

I understand step 1, how the private key is generated:
2CF24DBA5FB0A30E26E83B2AC5B9E29E1B161E5C1FA7425E73043362938B9824

I can see the prepended version number 80, and that I should append the compression flag  01

My question is around step 4, which is simply detailed as "Append checksum. Checksum is the first 4 bytes of double sha256 hash of whatever is being checkedsum'ed."

So I take 802CF24DBA5FB0A30E26E83B2AC5B9E29E1B161E5C1FA7425E73043362938B982401 and double SHA-256, and I don't get anything like the expected checksum of F29E9187

Can anyone help me understand how F29E9187 is derived?


texts: autogen.sh not working on Ubuntu on Windows

texts:
I installed Ubuntu on Windows, then cloned https://github.com/bitcoin/bitcoin in.

cd bitcoin
./autogen.sh

Which returned this:

: not foundh: 5: ./autogen.sh:
./autogen.sh: 6: set: Illegal option -

What am I doing wrong here? Have I missed something, or do I need to raise it as an issue on GitHub?

Thanks!

EDIT: Here is a screenshot:


texts: How can you sign a transaction without that signature being forged in the future?

texts:
So thinking here about an offline transaction. Both myself and the receiver sign it, and then at a later time that transaction is broadcast to the network in the block.

What is stopping me from taking your "signature" and signing another transaction with it in the future? How does this signature prevent itself from being forged by a malicious actor.

I'm assuming this has something to do with hashing / encryption or something alike. Somehow, I have to know that your signature is authentic without knowing the exact phrase or seed used to sign it, but a little confused on how that works.

Thanks!


texts:
Using Litecoin-QT

First I created wallet a. Then I sent 2 LTC to that wallet's public address.

Then I imported a private key in Litecoin-QT and wallet a was gone?! Aren't all .dat files  that has been used stored somewhere, or do they get overwritten everytime you import a new key to your wallet?


texts: Why are transactions grouped into blocks?(puzzle creation)

texts:
Why are transactions grouped into blocks (PART 2)?

Let's say we have just put a block on a chain. At that moment does a protocol create a new unique puzzle to be solved? Is the new puzzle known before that moment? Can different puzzles coexist at the same time (so that users solve different puzzles in parallel)?

EDIT: Puzzle in this sense means a combination of target (that changes every 2016 blocks), a hashing function, and other protocol imposed requirements miners use to guess the solution.


texts: Can I save mining fees when doing transitive transactions?

texts:
If I create two transactions:

Send BTC from output X to Y, no fee is attached.
Send BTC from output Y to Z, fee is attached (this depends on the previous tx).

Would nodes propegate these two transactions? Would miners mine them?

In other words, if transaction T2 depends on T1 and I want to broadcast both together - can I save some fees on T1?


texts: Has the nonce used in mining been sized?

texts: In the mining process, everytime a block has to be confirmed, a certain hash with an incremental nonce is generated: If the nonce is a 32 bit number it can assume a value between 0 and 2^32 - 1. It gives about max 4.000.000.000  attempts on the same block to find the right hash. But if the target begins with 13 zeroes why isn't 2^32 too little to find the correct hash?


texts:
I am attempting to get two nodes to talk to each other on the testnet, both nodes are on the same LAN.  After starting both nodes with the other node's ip address I get the following error when I check the status:

error: couldn't connect to server

In the debug.log file I have the following output:

msghand thread start
dumpaddr thread start
trying connection 192.168.1.121:8272 lastseen=359579.6hrs
init message: Done loading
connected 192.168.1.121:8272
send version message: version 70001, blocks=0, us=0.0.0.0:0, them=0.0.0.0:0, peer=192.168.1.121:8272
Added time data, samples 2, offset -18 (+0 minutes)
receive version message: version 70001, blocks=0, us=0.0.0.0:0, them=124.3.14.162:8272, peer=192.168.1.121:8272
getblocks -1 to 0000000000000000000000000000000000000000000000000000000000000000 limit 500
trying connection 124.3.14.162:8272 lastseen=2.5hrs
connect() failed after select(): Connection refused
trying connection 124.3.14.162:8272 lastseen=2.5hrs
connect() failed after select(): Connection refused

Public IP: 124.3.14.162

If two nodes are on the same LAN and they both get the same public IP, will that cause this error?


texts: Bitcoin fork! can I gain access to the coins

texts:
I wanted to know - I got some 1.18 BTC on blockchain.info and I noticed just now that there are allot of hard forks happened till now.
how is it possible to gain the coins from those hard forks ...and are those still live?

Name---Fork from---Fork height

Clashic Bitcoin 478559
Gold    Bitcoin 491407
Cash    Clashic 504032
2X  Gold    494784
Diamond Bitcoin 495866
SuperBitcoin    Bitcoin 498888


texts: what is wrong with this litecoin transaction? getting "tx rejected: (code -22")

texts:
raw hex:

0100000001390210797248b4f5a4a6c0fbcbde14a3ea132bdbfedb07aea35bff5cfc0766b1000000008a4730450220035db00b2bed0e4e97b92b9ee3610587110041c0e71f99b4563fe990d1a5a2b0022100ded70700477d36e7867dfb11842e86ef95e06e5fe910f4334730195493b362da41041862f45bcd7f2a0a8b2f1d24effdcede809ba4f46a78e5baac43ae0c0f6c651ceb02db5a9527ca9e722a4aca51284d6ee36408625b3463c68abfe3b5740aa42cffffffff0140420f00000000001976a914bee3bbfdad113a061739375edcfe6a908c096c7088ac00000000

I got this handcrafted tx from somewhere. I want to know why it is not being accepted.
From sendrawtransaction in litecoin-qt, I get TX rejected (code -22)

EDIT: I missed a zero in the beginning. Fixed it

Here is what I get using decoderawtransaction

{
"txid" : "a3de612bfa175d4c688648e205644305561f7d2cd96ae6a4ad23cabac4e3b887",
"version" : 1,
"locktime" : 0,
"vin" : [
{
"txid" : "b16607fc5cff5ba3ae07dbfedb2b13eaa314decbfbc0a6a4f5b4487279100239",
"vout" : 0,
"scriptSig" : {
"asm" : "30450220035db00b2bed0e4e97b92b9ee3610587110041c0e71f99b4563fe990d1a5a2b0022100ded70700477d36e7867dfb11842e86ef95e06e5fe910f4334730195493b362da 041862f45bcd7f2a0a8b2f1d24effdcede809ba4f46a78e5baac43ae0c0f6c651ceb02db5a9527ca9e722a4aca51284d6ee36408625b3463c68abfe3b5740aa42c",
"hex" : "4730450220035db00b2bed0e4e97b92b9ee3610587110041c0e71f99b4563fe990d1a5a2b0022100ded70700477d36e7867dfb11842e86ef95e06e5fe910f4334730195493b362da41041862f45bcd7f2a0a8b2f1d24effdcede809ba4f46a78e5baac43ae0c0f6c651ceb02db5a9527ca9e722a4aca51284d6ee36408625b3463c68abfe3b5740aa42c"
},
"sequence" : 4294967295
}
],
"vout" : [
{
"value" : 0.01000000,
"n" : 0,
"scriptPubKey" : {
"asm" : "OP_DUP OP_HASH160 bee3bbfdad113a061739375edcfe6a908c096c70 OP_EQUALVERIFY OP_CHECKSIG",
"hex" : "76a914bee3bbfdad113a061739375edcfe6a908c096c7088ac",
"reqSigs" : 1,
"type" : "pubkeyhash",
"addresses" : [
"LcdHTvKV5PNBbhcHrd1h3QRNcJLsxkfUfd"
]
}
}
]
}

EDIT: could be a problem with signatures. Can someone verify if the signatures are correct. I don't know enough about the litecoin protocol to do it myself.


texts:
I'm keeping a simple log of blocks, and storing them in an array. When a new block arrives, I add it to the array.

Let's say this is my block chain array:

E    <- tip
D
C
B
A

Now, say a new block arrives, extending a branch:

     Z    <- new tip
E    Y
D    X    <- new branch start
     C
     B
     A

Now the blocks C and D have been replaced in the main chain by X and Y.

Questions:

Is there a way to detect that the latest block has extended a branch?

In other words, how can I detect whether blocks lower down in the array need to be replaced?

How frequently does this happen?

EDIT: Initial solution is to check if the previousblockhash of the new block is equal to the hash of the tip in the array. If not, update the old tip, and keep working down through the array updating each block until their is a match for the previousblockhash.


texts: What are the minimal system requirements to run a full Bitcoin node?

texts:
I want to build a low profile system running as a full Bitcoin node, i.e. just running Bitcoin Core 0.9+ and pretty much nothing else. What is the minimal system (in terms of power consumption) that would be suitable for this task? Just bitcoind will do, no interface or visual interaction needed.

I'd really prefer something where I don't need to build all the software manually.

A simple small netbook would do, I guess. But could I even use something like a Raspberry Pi? Or perhaps some other single board computer?

I assume it'll need at least 20-30 GB disk space (for OS + Bitcoin Core with entire blockchain). Is there a minimum amount of RAM I'd need for bitcoind?

Curious to hear what kind of system and OS you guys would recommend for this!

(P.S. to avoid confusion: I just mean running a full Bitcoin node, not mining)


texts: How can I get the DateTime of when bitcoind last received a block?

texts: Is there a command to get the DateTime of when bitcoind last received a block?


texts:
What are the most famous crypto-currencies which use repeated hashes as proof-of-work?

What are the other proof-of-work methods?


texts:
I have read

  In the original Satoshi whitepaper, it was recommended that Bitcoin
  users use a new address for each transaction to avoid the transactions
  being linked to a common owner.

But in reality, when A buys a bitcoin from B, A sends money to B to B's account in an exchange (or whatever account.) It seems that B can be identified via this dollar transaction by an exchange or the authority?


texts: Besides Bitfinex, which crypto currency exchange(s) have Trailing Stop Loss

texts:
I was using Bitfinex until they stopped allowing U.S. clients.

They are the only exchange I know that has a Trailing Stop Loss feature.

Are there any others?

It's very dangerous to ones portfolio to trade cryptos without stop loss functionality if you cannot stay glued to your screen all day long. And a normal stop loss is too rigid to work well in the very volatile crypto environment.


texts: can i find my wallet address without opening bitcoin core qt

texts:
I havent ran bitcoin core qt for 4 years. And now the program wont run, just says bitcoin qt quit unexpectedly.

A: How can i check my bitcoin address and balance
B: How can i get the program working again.

driving me up the wall.


texts:
I'm new to bitcoin (core) wallet. I recently begin to use it to store some BTC. I'm using the latest version 0.21.0.
I have some basic questions on the keys/addresses it generated. I use command getnewaddress 3 times, the last item has "hdkeypath": "m/0'/0'/2", and I dumped its private key, and put some BTC in this address.

What's the relationship between the first pkey/addr (the one with hdkeypath: m/0'/0'/0 and the third one m/0'/0'/2? Does the first key/addr is the master (key) who can recover all later keys generated in the wallet.

I only backup the private key of m/0'/0'/2, and removed the whole wallet (the .dat file). Is there a risk of this method? Since I only choose to use this key/addr to receive and store BTC.

I later create a new wallet and restore this m/0'/0'/2 key with command importprivkey. and send some BTC to other people, and found it generate a CHANGE addr, so I also backup this new addr's private key too. Since I mainly use this m/0'/0'/2 to store long term BTC, and will not use it to make a lot transactions. So I keep the privatekey of m/0'/0'/2, and keep backups priv keys of change addresses it generated, then drop all wallet files. Is this method enough to restore all my balances in a futher day.

Can the private key of m/0'/0'/2 be used to recover the change addresses' private keys? (What is the master seed of HD wallet, it is the private key of m/0'/0'/0?)

Thanks in advance


texts: Manually crafted multisig Tx: non-mandatory-script-verify-flag


texts: Help - Running R9 290x graphics card headless in Linux

texts:
Running Ubuntu 13.10. When I hook up the card to a monitor through HDMI, cgminer detects the card. When I unplug the HDMI cable from the monitor, the system throws a blank screen. I can ssh in from another computer, but when I run cgminer, cgminer tells me that the card isn't detected:

"clDevicesNum returned error, no GPUs usable"
"0 GPU devices max detected"

From various online forums, people have stated that dummy plugs won't work on the R9 290x because this card has only digital inputs (AMD got rid of analog), so the resistor trick won't work here even with DVI-VGA passive adapters.

Furthermore, people have said that with newer cards like mine, dummy plugs aren't necessary.

The only difference I see is that I'm using ubuntu while the people in the forums were using Windows 7 or 8. However, I'm using Catalyst 13.12, so I should be good?

What am I doing wrong? Can someone help me?


texts: What is the incentive to broadcast the whole blockchain? What is the incentive to broadcast unprocessed transactions?

texts:
Among the strengths of bitcoin is that it mostly allows all actors to act in their own best interest. There are some actions however of which it is not so clear to me what is the direct incentive other than some kind of idealism.

Obviously it is in a miner's best interest to immediately broadcast a newfound block, or blocks that validate blocks mined by him.

Is there a direct incentive to broadcasting the whole blockchain though (i.e. operating a full node)? Likewise, is there a direct incentive to broadcast all transactions to other nodes immediately? Naively I would think that it could be advantageous to a miner if other miners don't have access to some high-fee transactions.

Of course, for both it is necessary that enough nodes do it for bitcoin to function smoothly, but I am interested in the incentive for an individual miner.


texts: Bitcoin Withdrawn from Cryptobridge not showing up on my Bitcoin Core Wallet

texts:
Hey so I sold my Argo on Crypto-bridge and received bitcoin. When I withdraw said Btc to my bitcoin core wallet, how long does it take for it to show up?
There are two transactions in question here:
1) I withdraw the bitcoin to my wallet when it was syncing. Now that the syncing is done, I don't see anything show up. It's been 2 days now
2) I withdrew bitcoin to my wallet after it was done syncing. How long will this one get into my wallet. This happens today.

Both of these transactions have went through on Crypto-bridge but never showed up on my end.
My wallet address for bitcoin is

13zQ6niRwL4kWrJs76BCsf3FmERtBWDYke

Is Crypto-Bridge a scam market?

Please help me out


texts: Why is my withdrawal from the 50BTC pool not visible in the blockchain yet?

texts:
I did a bitcoin transaction of 216 BTC from the 50BTC mining-pool to my wallet (Bitcoin-Qt).

It has been 3 days now and I have not received anything yet.

I've tried to search my address on blockchain.info and it doesn't come up.


texts: What is the need for multiple private keys?

texts:
From what I understand, there is initially a seed from which the private keys are derieved and from that the public key respective to each private key is derived.

The public key is essentially the wallet address. So now say I wish to receive 10 BTC from Bob. So Bob makes a transaction "paying 10 BTC to wallet address #####(mine)" and signs it with his private key.

I (or the validators for that matter) can verify it by looking at the digital signature with Bob's public key. And if I have to send 10 BTC to Bob, I do the same as above.

What I don't understand is what is the use for having multiple private keys when just a single one can suffice? (I've read somewhere that wallets act more of a storage for keys than storage for Bitcoins, that's why the doubt).

Also, if there are many private keys (=> public keys => wallet address) pertaining to each transaction, how does it become possible to trace back to the previous transactions as each has a different address?


texts: Can we get any default address before running getnewaddress?

texts:
I am trying to develop some application using bitcoin (currently only in the regtest mode).
I am aware that one can create a new address using

bitcoin-cli -regtest getnewaddress

RPC call, but I want to know whether bitcoind pre-generates a bitcoin wallet address when we install and run

bitcoind -regtest -daemon

fresh. If yes, how can I know this address?


texts: What is the cheapest Bitcoin -> prepaid VISA/Mastercard service?

texts:
I am looking for the cheapest Bitcoin to prepaid VISA/Mastercard service for the amount of $5000. I have noticed some with a maximum of $100, and inquired whether it would be possible to increase this cap. It is really not interesting to have to buy 50 cards, and ensure that one empties each of them. $1000 on each card is acceptable though.

The card needs to work for purchases in any country.


texts: Why are miners allowed to not announce their mined blocks to the network?

texts:
My question relates to a 51% Attack. As far as I understand, for this to work the miner must have a secret fork of the main blockchain, which he will later announce, whenever it becomes longer than the main blockchain, thus reverting a previous transaction and permitting double-spending.

So then, why not just force blocks into the main chain the moment they are mined? What is the rationale for these private forks?


texts: How can I import a private key into a pruned node?

texts:
I am trying to restore my Bitcoin Core wallet, but I only have the private key and passphrase, I don't have a wallet.dat file.
I tried using
importprivkey privatekey xxxxxxxxxxxxxxxxxxxx

which gave me the error Rescan is disabled when blocks are pruned (code -4).
How can I import the key?


texts: Mnemonic seed BIP 39 HD wallet with vanity address

texts: Can we create a mnemonic seed BIP 39 HD wallet with vanity address for LITECOIN, if yes, how?


texts:
I am using bitcoin-rpc and everytime i create an invoice for the client to pay, i create a new address. Payment is ok, i get the money after a cron.php sees that all confirmations are above 3, but then when i try to send my money back to my big wallet i see 200 300 usd in fees
bitcoin-cli sendtoaddress "MY_WALLET" 0.1 "" "" true
I see on blockchain that everything was sent from each and every address that i have created
ADDRESS1 ... 0.05
ADDRESS2 ... 0.08
ADDRESS2 ... 0.028
... and so on
How can i send everything from one big address and pay only 20$ usd fee?
I think i pay per vbyte for what i have read ... but i want to send internally with low or no fees or something. Can i send coins internally to one big wallet?
I mean don't think that big payment gateways that do the same thing and create an address for every invoice but pay such amounts of fees.
Thank you.


texts: How does solving reduced difficulty hashes contribute to solving a block?

texts:
In pool mining, it's my understanding that miners solve a reduced difficulty hash which proves that work is being done and also simultaneously helps solve a block.

How is this computationally possible? and how can the pool difficulty be different from the Bitcoin block?
I guess I don't understand how work on blocks is computationally divided among pool miners.


texts: Question: My friend in India wants to start investing in cryptocurrency such as bitcoin. I have a few questions. What is the current legality of cryptocurrency in India? What exchange should he use? What wallet app should he use (should support main popular coins)?


texts:
In PoW algorithm a miner has to solve a mathematical puzzle whose difficulty depends upon load on network and total computing power. But who decides what would be that puzzle for each block?
For Example I am mining a block and I have to solve following equation A + B = C now I have A and I have to find B
 to solve this equation but who in blockchain network provides C (predetermined number) for each block ?
Or
How do the other miners verify that he really did find the winning hash?


texts:
Recently my HDD went, losing all of my data. I make backups frequently and luckily only lost 0.02BTC. I tried everything to recover them, but no luck. As I stated it was small amount that wasn't a much for me to pull my hair out. Just bang my head against the wall. And miss out on a day of coffee.

But this got me thinking. Is there a way to find out how many bitcoins in the world are missing?

I'm guessing that about 6000 transactions after all of the bitcoins have been mined, someone may be able to develop some sort of spider, bot or scrapper of some sort that will index the blockchain and make an educated guess by looking at the transactions.

And if that is so wouldn't it be possible to also determine the Bitcoins that are missing and remake or counterfeit the missing bitcoins?

I know Bitcoin uses SHA encryption. But with good computing power, the knowledge of none being made again. Couldn't something like rainbow tables be created to forge the missing bitcoins?


texts: What's the difference between BTC and BCH transaction capacity?

texts: If Bitcoin can process x transactions per second, how many transactions per second can Bitcoin Cash process?


texts: Do I need to join a pool if I have a 3TH mining rig?

texts:
I am thinking about purchasing a 3TH mining rig and would like to know if it is still worthwile me joining a mining pool to mine BitCoins?

Do I have enough power to go it alone?


texts: Moving armory watching-only .wallet file

texts:
I have set up an offline wallet on computer "A". I set up a corresponding watching-only wallet on computer "B". I have signed and broadcast several transactions. But now I wish to safely move the watching-only wallet to a different computer "C". Then delete the watching-only from computer "B".

Should I import a digital/paper wallet backup of the watching-only wallet? Is this enough to ensure all existing adddresses and BTC are moved?
Or should I copy the actual .wallet file manually?

Can this proces be repeated without issues?

Thanks


texts: Can I get the same stats as are on blockchain.info and btc.com by running a full node?

texts:
There seem to be some discrepancies between blockchain.info and btc.com, specifically I am looking to extract the following info:

"Relayed By", there was a block that was listed as unknown on blockchain.info and showed as "relayed by" by specific mining pool on btc.com
Is there a way to figure out hash rate of specific mining pool as a % of total in the real time.


texts: Why is my transaction still pending? Its been 72 hours!

texts:
I bought some BTC off a friend a few days ago, and I'm still waiting for the transaction to be confirmed.

https://blockchain.info/tx/90136a914ebcb15d236b21b1bcd48e0744b97868ae570b9b30d1359361fdccce

Its been 72 hours.. What can I do?


texts: Is there anything I can do to speed up the synchronization of litecoinj?

texts:
I am using litecoinj which is forked from bitcoinj but compared to bitcoinj, the wallet creation and block synching is slow when using litecoinj. So, I searched for a solution and found a post that suggests to download checkpoints in a file and pass the file while creating wallet, but I guess it's not working.

kit.setCheckpoints( new FileInputStream("checkpoints"));

How can I speed up the syncing of litecoinj?


texts: I want to struct a transaction output the key-path of which I want to be eliminated, so enforcing only the script path. In order to eliminate key-path, in my opinion, I should set "Internal Public Key" to "0xFFFFFFFFFFF.." making the corresponding "Internal Private Key" unknown so the key-path signature is. By doing so anyone interested in unlocking this output, including me, must follow the script path by fulfilling its conditions. Correct me if I'm wrong. Thanks.


texts: I LOST MY FUND EVEN ALREADY IMPORT WALLET

texts: I cannot recover my fund in Copay Wallet. I done import wallet using my back up 12 phrase word but yet still cannot recover. Why?


texts: Why do I need my password to generate a new receiving address in bitcoin-qt?

texts: I heard that the wallet has 100 of the next receiving addresses already.  Shouldn't I be able to get one of those without unlocking it?


texts: How do I calculate transaction fee for call to createpsbt()?

texts:
When my user invokes my app, he passes as an input parameter the desired value of the TX fee in satoshis per byte.  I create a PSBT by calling createpsbt().  I exert complete control over the determination of inputs and outputs.  For example, I don't call walletcreatefundedpsbt(), because I don't want bitcoind to select inputs on my behalf.  I have a chicken and egg problem in that I need to call createpsbt() in order to determine the size of the TX in bytes, but I need to specify the fee amount before the call to createpsbt().  The best solution that I can think of is to execute a dummy call to createpsbt() using a dummy fee value, then measure the size of the TX, then do a real call to createpsbt() after correctly calculating the fee amount.  Is there a better way?

Edit: I want to spend all UTXOs.  I want two outputs, one to receive a fixed amount, the other to receive change less the fee.  I have tried many incantations, I can't get it to work.  Here's my latest attempt:

raw_psbt = rpc.walletcreatefundedpsbt(
    # all UTXOs, as returned by listunspent():
    inputs,
    # one recipient: [ { addr : amount } ]
    outputs,
    0,  # locktime
    {
        "replaceable" : True,
        # I would like for the change less the fee to go here:
        "changeAddress" : xxx,
        "includeWatching" : True,
        "feeRate" : 0.005,
    }
)

This fails with Signing transaction failed (-4).  Any idea what I'm doing wrong?

Edit #2: I can't use walletcreatefundedpsbt() as suggested below to create the PSBT, because that function requires that its inputs be "solvable", which is not the case in my environment.  More info at this link:

Errors with walletcreatefundedpsbt & non-solvable UTXOs

So my original question remains unresolved at this point.

Edit #3: So I asked on Slack.  The problem is that our UTXOs are 1) not "solvable" and 2) cannot be expressed in the descriptor language, so Bitcoin Core has no way to calculate the TX size before the TX is signed.  Apparently I would have to calculated it manually as explained in the attached screenshot.


texts: What are some good online Bitcoin wallets based on client-side security?

texts:
I just found Bitventory, which seems to be an online wallet service that requires a minimal amount of trust (it's the major design goal, at least).

Are there other services with similar goals or functionality?


texts: Wrong Address when Transfering BTC to Paper Wallet

texts:
I think I fucked up when transfering my BTC from exchange to paper wallet.
I used the private Bitcoin address you get when u make a paper wallet instead of receive address generated in blockchain.info. The transaction was confirmed but the BTC never received.
Where did the BTC go?


texts: How BitcoinJS sync bitcoin blockchain/transaction data?

texts:
I see the reference code in BitcoinJS website about 'Creating a Transaction':

var tx = new bitcoin.TransactionBuilder()

// Add the input (who is paying):
// [previous transaction hash, index of the output to use]
var txId = 'aa94ab02c182214f090e99a0d57021caffd0f195a81c24602b1028b130b63e31'
tx.addInput(txId, 0)

My question is how it get the data about tx(like its inputs/outputs)? Does it link to some nodes or API like blockchain.info?


texts: Who are the key developers, and where can I follow their progress and decision making?

texts:
I want to follow the most up to date developments of Bitcoin, (such as M of N transaction confirmation).

Who are the primary developers of Bitcoin and what is the most efficient way to track the progress of this and similar activities?

I'm interested in reading either a detailed activity view, or a high level bullet point of key developments.  Ideally someone would offer both information formats as an answer.

A nice summary view would include the following ideas and a status on testnet and on the production network:

IPv6 support
Zero confirmation AKA miner promise


texts: can someone please help me I am lost i transfered coins from paxfull to bitcoin core

texts:
I bought bitcoins to pay a bill. which never happened because of something called protcal? IDK.
then i read online that bitcoincore was a good wallett to transfer and pay bills. now I have no idea how to use it or see them. someone please help.. dumb damsal in destress


texts: Transaction verification vs block mining

texts:
I cannot clearly understand if the transaction verification is done over a single or double phase. This is my understanding.

Once a transaction is completely assembled, its inputs and outputs defined with all the conditions, the inputs can be checked to make sure the sender has enough balance to process the transaction.
Block mining is performed to time stamp the transaction and prove that it existed at a certain timing. Therefore block mining is more of a confirmation that the transaction has occured at a specific time rather than checking the validation of inputs.

If what I said is correct, who performs step one. Is it done by the receiver to make sure that the sender actually owns a real balance to make the payment?

If what I said is wrong, are step one and step two done together by the miner. And can someone please provide more detailed description of this verification process of inputs and time stamping because the none of the previous questions and answers address this clearly.


texts:
Is it possible to launder cash this way:
Purchase bitcoins at an atm using cash. This is completely anonymous right? Then sell them on an exchange and report the gains there to the IRS as if they were mined bitcoins. Possible?


texts:
Does someone understand this?

  "Because of all this work, when a Bitcoin client signs on to the network it can trust the block chain that was most difficult to produce (since this is evidently the one that was being worked on by the most miners). If there was a "fake" blockchain competing with the real ones (say, where someone pretends that they didn't actually give Sofia those 8.4 bitcoins and they still have them), the fraudster would have to do as much work as the whole rest of the network to make their block chain look as trustworthy. So essentially, the intense work that goes into finding blocks through hashing secures the network against fraud. There is also, of course, some nifty code that figures out how to choose between conflicting transactions; and what to do if two people find valid blocks at the same time."


texts:
This message appears in my debug.log:

2017-01-21 00:16:42 Opened LevelDB successfully
2017-01-21 00:16:42 Using obfuscation key for /home/<username>/.bitcoin/blocks/index: 0000000000000000

As does this:

2017-01-21 00:16:42 Opened LevelDB successfully
2017-01-21 00:16:42 Using obfuscation key for /home/<username>/.bitcoin/chainstate: <removed>

What is an obfuscation key used for?


texts: Will it be possible to export a key and only allow it to be imported once?

texts:
When the import/export key be implemented I would like to know if it will be possible to export a key with an option like: The exported file can only be imported one time, or that the exported key was exported with an option that removed the key from the wallet that exported it. I ask this because I would like to receive for example a exported key file from someone but with the certainty that the key is not on this someone wallet anymore (or any other wallet).

Will this be possible?


texts: download bitcoin core safely: wrong checksum

texts:
I've downloaded the "classic" linux bitcoin core 0.19.1 (tgz) on https://bitcoincore.org/en/download/

In the SHA file that's on the website this is the key:

  5fcac9416e486d4960e1a946145566350ca670f9aaba99de6542080851122e4c  bitcoin-0.19.1-x86_64-linux-gnu.tar.gz

In my terminal, when I do sha256sum filename, I don't get this key.

Also when I run this I get a [FAILED]

  sha256sum --ignore-missing --check SHA256SUMS.asc

1) Am I doing this right ?
2) if yes does it mean bitcoincore.org compromised ?


texts: Lightning Network: Is it creating 3 transactions instead of 2?

texts:
I'm watching this Lightning Network presentation by the original authors.  At 9 minutes in, he notes that all the network sees will be a transaction to the multisig address and then a transaction to Alice for 0.8 BTC and a transaction to Bob for 0.2 BTC.

Is all of this effectively 3 transactions?  Would it not be cheaper and clog the blockchain less by simpling having Alice send 0.1 BTC to Bob and then another 0.1 BTC to Bob and have 2 transactions instead of 3?


texts: how do devs upgrade bitcoin core without affecting the live active network?

texts: I've always wondered, how do devs developing on Bitcoin upgrade the system without affecting the live network? We typically see a site under maintenance when big companies revamp their site, but how does Bitcoin do it?


texts: Why do transactions get verified before it is clear that the block header is valid?

texts:
When I researched for the answer on What happens in detail, when Bitcoin Core verifies a block during synchronization?, I noticed something:
According to the Wiki-Entry on Protocol rules some of the transactions' traits are checked before all header data is verified.

Why do the following checks of difficulty statement and timestamp get performed only after transactions get looked at?

  Check if prev block (matching prev hash) is in main branch or side branches. If not, add this to orphan blocks, then query peer we got this from for 1st missing orphan block in prev chain; done with block
  Check that nBits value matches the difficulty rules
  Reject if timestamp is the median time of the last 11 blocks or before

Wouldn't it be more efficient to check the relation to the main chain and timestamp first, and then check the legality of the transactions?


texts: Simplest and fastest method of utilizing Bitcoin for my online digital store?

texts:
I am not very versed in digital technology but am very interested in its potential and decentralization benefits.  My question/s

I'm looking for the easiest and fastest method to allow a person who has never heard of Bitcoin to purchase Bitcoins and then use Bitcoin as a payment method on my online store.  Most people do not want to be bothered by going through a lot of technical gyrations in order to purchase a digital product on line using Bitcoin if it involves a lot of steps and or requires a background in computer expertise.  I need something that is simple so that even Grandma can do it....

Example:

Time to check out
We accept Bitcoins
Purchase Bitcoins...."click"
The person uses for example PayPal or credit card to purchase Bitcoins and then
Returns to checkout and purchase my goods and or services using their Bitcoin money
The Bitcoins go directly to my Bitcoin Wallet, and they receive their goods

Thanks for helping, I am a little handicapped in this area.


texts:
From my understanding, you simply need to use a SHA256 function to hash the block's header (Block hash and merkle root) then add the nonce at the end like this article explains.

However, I can't manage to get the correct next block hash.
By using the block #505400 :

Hash : 00000000000000000023b89dd18f6be5a6c03a71cd864ccbdf024683114b9ce3

Merkle root :  a3defcaa713d267eacab786c4cc9c0df895d8ac02066df6c84c7aec437ae17ae

Nonce : 2816816696

Next block hash : 0000000000000000007625ff74171cf53e301c3e5013bf2184e2629a2da0fc8d

What I am expecting : sha256(Hash + Merkle Root + Nonce) = Next Block Hash

However I get this : 10345cb85ffed406a47e1faf31eb8ba1160aac0fbaae3cae0cd66889f9c9f49e

What did I do wrong?


texts: Error message in cgwatcher with intel hd graphics 4000

texts:
The error message is :  "the miner path for the active default profile (chemin vers cgminer.exe) does not exist. You must set the miner path before you can start mining. Click the manage profiles button in the settings tab to open the profile manager, where you can edit the profiles miner path".

I am using windows 8 with intel i7.

What can I do ?


texts: why is this transaction I made being rejected?


texts: Why did this empty transaction block get awarded 25 bitcoins?

texts:
I just saw a new block go by at height 238440 on Blockchain.info that has no transactions but awarded 25 bitcoins. How is this possible, and, why is it possible?

Here is the block information link: https://blockchain.info/block-index/386860/00000000000000db143554fa093eda1e7d608309f733170c4c7ea2777cfd5424


texts: corruped wallet.dat / Nversion / bitcoin 0.20.0/ pywallet or other... LILTLE Reward?

texts:
Good morning all
I introduce myself dydy94 ...
I am not an expert in coding but I learned well, the few days preceding this post ...
I also got lost a lot: / LOL ...
Here, good, I offer 25 $ / 25eu or 25 £ to the one who will help me to extract the private keys from my wallet.dat wallet towards my ledger wallet or blockchain.com or elecrtum
In my opinion, (this is only my opinion but you can answer it) the decoding and the extraction of private or pub keys or addresses ...
etc
Has changed a lot compared to the time (I explored the methods without finding the right one) but It seems to me ...
this is where i am:

recovery of "wallet.dat backups"

test pywallet.py with -recover (etc ...)

test pywallet.py with --dumpwallet -dumpwithbalnace --datadir> wallet.txt (it gave me the portfolios, unfortunately "NVersion 200000, for those who know)

test pywallet --web (never made it work)

replace wallet.dat but I did not wait for the end of synchronization (much too long)

I stopped there I was patient, but there I need help ...
I pay $ 25 to whoever gives me the correct code route, public is better for everyone or in private of course I will pay it!
I will put the question on -bitcoin.stackexchange and maybe later on -bitcointalk if I don't have answers ...


texts: How do Bitcoin nodes know where to send new transactions and blocks to?

texts:
I am researching Bitcoin; what I can't find much information on though is how the P2P network itself operates. For example, BitTorrent uses a DHT protocol that allows for node discovery and calculating distances between nodes etc.

So if a Bitcoin client wants to do a transaction, how does it know which IP address to connect to in order to announce it?

And how does the node that the transaction gets sent to know which other nodes it needs to connect to, and so on?


texts: Is new cryptocurrency that runs only in raspberry pi possible?

texts: Is it possible to create a cryptocurrency software that can run efficiently on a raspberryPi and has a mechanism to detect (based on maximum coin production?) if a node is using a better computer so the swarm rejects it's coins?


texts: Question about nSequence with regard to bip-0112 and bip-0068

texts:
So far my understanding is that when you create an op_csv output the value entered before the OP_NOP3 is an arbitary number, lets say 10.
This number can be interpreted as block based of time based depending on the nSequence value set when spending (according to bip-0068).

What I am confused about is the following, say my first transaction has a redeem script as follows

10
OP_NOP3,
OP_DROP,
alicePubKey,
OP_CHECKSIG

Does this mean that the spender, who sets the nSequence type flag (1<<22) to either on or off whilst creating the spend transaction, effectively has the ability to decide whether the 10 is interpreted as block based or time based?

It seems the granularity of the time based option is 512 seconds, so close to an average block time.

Thanks


texts: My bitcoin transaction does not exist in blockchain.info nor does it exist in any tx accelerator

texts:
I sent bitcoin to myself using Breadwallet.
Before that, I went to my Breadwallet which I made a purchase from a few days ago and when I login it says something about a payment being rejected so I'm thinking I got refunded for the purchase I made.
I go and try to send myself the bitcoin to my main wallet and then it says there's a transaction error and it said I needed to synchronize the wallet with the block chain or something similar. After that happens, it shows me that my older payment has been sent and my newer transaction of me thinking it was a refund is also being processed and is stuck on 40% but when I try to track the transaction using blockchain.info using the transaction id it says the transaction can't be found. This is the transaction ID: 9c542c7e6f31d313ba637ef95c7a6fc125ab0a0f7ea2e8a790babfac22a3df57


texts: WalletAppKit creates an address every time Bitcoinj gets initialized

texts:
I'm implementing an app using BitcoinJ, but every time I run the code, a new address is created. Is there any way to work with the very first address that was created and stop creating new addresses?

walletAppKit = new WalletAppKit(parameters, walletDir, "my_wallet") {
        @Override
        protected void onSetupCompleted() {

        if (wallet().getImportedKeys().size() < 1)
           wallet().importKey(new ECKey());
           walletAppKit.peerGroup().setBloomFilterFalsePositiveRate(0.00001);
           setupWalletListeners(wallet());

           for (Address address: wallet().getIssuedReceiveAddresses()){
                Log.d("myLogs", address.toBase58());
           }
        }
    };
walletAppKit.setBlockingStartup(false);
walletAppKit.setUserAgent("RocketWallet", "1.0");
walletAppKit.startAsync();


texts: How to calculate the transaction size from the signed hex encoded?

texts: Suppose I have a signed hex encoded transaction (as returned by RPC call  signrawtransaction), how to get the size, in bytes, for purpuses of calculating if included transaction fee is acceptable by the official client? Can I simply get the size in bytes of the hexadecimal decoded to binary?


texts: Bitcoin library vs script to develop application

texts:
I'm curious about the development of application of Identity management in Blockchain platform, but I'm a bit confused about the technologies to use.
In short words, when is more convenient to develop an application coding in script and when is it better to use a high-level library like BitcoinJ or a service as Blockchain.info API?
I'm a Java developer and I'm more confortable using a Java Library like bitcoinJ, but I don't understand if, in this way, I can lose something in performance or expressivity or "semantic power" in regard to most raw-level scripting system of Bitcoin (that is a kind of assembler).
Thanks you in advance


texts: I'm trying to create a website that will allow me to accept payment in bitcoins. What I need is a way to integrate the wallet with the website so that I can generate a unique address to give each user to deposit the bitcoins. The reason to create a different address for each user to pay is to create a sense of anonymity. The site is purely for transactional purposes and not for mining. How do I generate a unique valid address for each user?


texts: I was called by someone when I tried to withdraw my money, who works for Bluesave,  but when I log in the platform was Optima platform and when to proceed for withdraw he send me to Jubiter page. The problem is that the first time when I opened my account was in March and I put a deposit of 275 euros. Today I requested my money back and he took another 275 euros from my account saying that is the verification procedure. And then he said, in order to send me the full amount in my bank account I have to buy some bitcoins for about another 500 euros. I am concerned about this transactions an I want to ask if this is the correct procedure in order to get my money back?..If not what can I do to get them back? Thank you


texts: Where can I find a Windows binary of MultiCoin?

texts: MultiCoin is AFAIK the only GUI client that supports NameCoin. Is there a trusted Windows binary to be found?


texts: Can Bitcoin Tech be Used to Protect Journalists

texts:
Over eight Nigerian journalists are currently in police detention because they published investigative news stories that didn't sit well with the government of the day.

How can the bitcoin technology help journalists facing government suppression, especially regarding giving up their information sources?

Can the blockchain technology be used in a way to protect journalists from having to reveal the identities of their sources? How?


texts:
If I'm sending someone my wallet address, am I making my account balance visible to him?

As far as I understand, all transactions are public, which means that if I know an address, I can reconstruct the current account balance via the blockchain.


texts: When Schnorr signatures are part of Bitcoin will it be possible validate each block with only one signature validation?

texts:
In a recent talk Pieter Wuille talked about speed up verification when using Schnorr signatures and various algorithms for verifying multiple signatures.

Would it really be possible to verify one single block by aggregating the keys and signatures of all transactions? (In theory even more transactions over several blocks)

I assume this does imply that the old ECDSA scheme would not be used anymore. If we were backwards compatible we could probably only do this for transactions that used Schorr signatures where as the other ones would have to be verified one by one.

(Leaving aside politics of drastic protocol changes) Couldn't we even save more space if we adopt the block header to include one aggregate Schnorre signature for the block and leave out all the schnorr signatures of the single transactions within that block?

Did I miss anything? The talk did not give many details but just mentioned the idea.


texts: Bitcoin Full Node + Lightning running on single-board-computer, possible?

texts:
I know similar questions (regarding a Bitcoin Full Node) were already asked here, but they date all back to 2014 and I think especially the space needed by the blockchain changed a lot since then.

I am thinking of buying a single-board-computer to turn it into 24/7 online bitcoin full node + a lightning node. I want a single-board-computer to reduce the energy consumption, since it is running 24/7. My question is now what single-board-computer I should buy and how well that works. I read a lot about Raspberry Pi 3 and that its not working very well so I think of buying something more powerful.

At the moment I am thinking of a Banana Pi M3 or an ODROID-XU4.

Did someone already try something like this with another single-board-computer than the Raspberry Pi 3?


texts: Can a hard fork effectively double the value held in bitcoin?

texts: A hard fork necessarily means that two versions of the block-chain exist and value is held in both. Now realistically one of them should probably go down in value and the other increase or hold steady such that the total value held in them is roughly the same at the end of the day ( assuming a rational crypto-currency market). However assume that the market is undervalued and somehow the market decides that both the blockchains have the same value or that the new one is way more valuable than the older one, with the latter holding its value; isnt that equivalent to something like 4 billion dollars of value being created out of thin air? And also, how likely is that scenario, especially in the context of bitcoin classic....


texts: Get scripthash for known scriptPubKey in python

texts: I have to query addresses in ElectrumX server. How do I generate scripthash for a known scriptPubKey in python? If my bitcoin wallet address is 1P5ZEDWTKTFGxQjZphgWPQUpe554WKDfHQ ，I want to convert to scripthash


texts:
One question about the inner working of the mining process:
I know there isn't such a thing as a block 30% or 99% mined, or a mine is blocked or it isn't, I get it. The thing is: how do the transactions that belong to a block (that dole out transaction fees) get incorporated into the block after it has been found. Are these transactions being processed along with the mining and that's what the mining process is all about?


texts: Is there a website that tracks Bitcoin taxes paid to local government?

texts:
One thing that would further legitimize Bitcoin with government oversight is the payment of relevant taxes to Federal and State government (in local equivalent currency) for e-commerce and mining activities.

To this end, I think it would be good to highlight the legitimate business models, and how much tax revenue those companies are bringing to their community. One way this could happen is to have a website of sorts that details the tax paid on the transactions and/or mining.  Perhaps this could be detailed on a per country basis.

Is there any effort underway that is attempting this?
If not, what are some possible ways to publicize the taxes paid to each local government?


texts:
What problems identified with bech32 addresses have been resolved with the updated bech32m?
I am aware of one problem with the original bech32, namely length extension mutation weakness but I don't know if there were any others.


texts:
Importing a private using the debug console causes a crash, I always have to kill from shell the bitcoin-qt app and restart it.
Is there any way to prevent this?
Is there a way to import the private key into qt client from shell?


texts: If I use a multi-sig wallet for Bitcoin, and require a total of 2/3 keys to sign a transaction, does that mean that the total time would be limited to the time to confirm 2 signatures ie ~ 20 minutes if done simultaneously?  And would it cost the same as a regular Bitcoin transaction?


texts:
I know that CPU mining wouldn't pay for electricity bill, but what if some sort of CPU miner was deployed to a website? Similarly to CoinHive with Monero. Would such mining make sense?
I started mining Monero with CoinHive on my website today.

I did a little research on slushpool's mining proxy. I wanted to deploy it on a server to be able to mine on non-supported mining tools. I had no luck with that - my shares were always REJECTED.

I'm planning to do the same research with ETH. Would such approach make sense on any other currency than Monero?


texts: How to handle multiple transactions from the same account(address)?

texts:
I am new to bitcoin so please bear my question. To understand the IN's and OUT's of this crypto world, i am creating a dummy bank to have a better understanding of the system.

So I have a bitcoin core running in my local system. Now for each user in the system I create an account for them using the getaccountaddress.

So let us consider I have one account named A having a deposit of 10 BTC. Now, suppose the user A wish to withdraw 1BTC from his account so, I first find all unspent transactions filter it by address associated by account A and send this 1BTC to user A. Now as I understand that the bitcoin cannot be partially spent so the remaining change will go to a change address so I provided account A's address from which the transaction was created.

Now my problem is that if the user again wishes to withdraw, I cannot find any unspent transaction since the change is not yet received immediately and will only be available when the transaction is confirmed.
So what is better way to handle this? What is a typical standard to handle such situation? How does wallet like Electrum works as I can see that I can send multiple transactions one after another.


texts: Underclock GPU Memory below "Recommended" Limits on Linux

texts:
I'd like to try underclocking my GPU Memory. Based on what I've read, this is frequently done to reduce heat without sacrificing hashrate, and can sometimes even boost the hashrate if done carefully.

I seems that those running on Windows have a tool called "Afterburner" that allows them to over/underclock beyond the manufacturer's recommended limits, without flashing their BIOS.

However, under Linux, aticonfig --odsc=XXX,YYY won't allow setting the memory clock any lower than the range displayed by aticonfig --odgc.  Other tools I've investigated, such as AMDOverdriveCtrl, appear to just be front-ends for aticonfig, and therefore limited to what it can do.

I've seen some mentions that flashing on a new third party BIOS rectifies this, but that makes me more than a little nervous, so I would prefer to avoid that.

Would someone please explain, either...

A) How to underclock the memory on ATI GPUs (6850 and 6950, specifically) on Linux beyond the manufacturer's recommended limits, without flashing the BIOS.

... or ...

B) How it's possible for tools running on Windows to have more control over the hardware than those running on linux. (This feels like a slap in the face to me.)


texts: How does the security of a mobile wallet work?

texts:
Let's assume we have a non custodial hd mobile wallet.

Where is the master key stored?
What are the components of the telephone that allow the derivation of keys?


texts: How to uninstall Bitcoind from ubuntu server?

texts: I installed bitcoind on my ubuntu server awhile ago. How do I go about uninstalling it properly? Do i just delete the ~/.bitcoin folder?


texts:
I'm trying to accept bitcoin payments on my website using blockchain.info's API. However, I'm confused with their callback.

I've read through their callback, but how would I know if the transaction was successful or not ?


texts: Will I be losing my BTG by sending BTC to bitfinex

texts: I have my BTC in my trezor wallet (had it for a while before the BTG fork), now I would like to send some BTC to Bitfinex, but I am worried that if I do so, it will also send my BTG to the same address on Bitfinex and so losing my BTG. Can anyone tell me if my assumption is correct ? Thanks


texts:
Is there an obvious way that I can achive the following with Bitcoin?

An organizer sets a goal: an amount of bitcoins must be gathered within a specific amount of time
Random pledgers send an amount within specified boundaries (min/max amounts).
If the goal is reached within the specified amount of time, the organizer collects the pledges
If the goal is not reached within the specified amount of time, the pledges are returned to the pledgers

AFAIU the above model is similar to Mike Hearn's LightHouse project, however I cannot use this great platform for my project and on top of that I would like to be sure that I'm headed in the right direction, so any ideas and alternatives on how to achieve the above are more than welcome.


texts: What are the limitations to an outdated backup?

texts: My backup private keys were made in Jan and my computer crashed in May. If I upload the keys on a new wallet, will it show my bitcoin balance from May or January?


texts: Interpretation of first circa 70 000 blocks

texts: I've sampled a significant number of the first circa 70 000 blocks to conclude that they all serve only to create Bitcoins (50 at a time).  I will accept that my question does not have a factual answer and may therefore be closed on account of the speculation required to answer.  Nevertheless, the question is: is the 'money creation' of the first 70k transactions why some say that the creator of the system may be in possession of a third of the bitcoins ever created?


texts: How to keep node mining automatically in qt wallet or console wallet

texts: In the qt wallet, manually need to start the mining process in wallet console by giving generate nblock. so is there any other command or solution to automatically mine the block and how to confirm the transaction.


texts: Can TREZOR sign transaction with input address beyond gap limit?

texts:
Suppose I use TREZOR with Electrum or Bitcoin Core HWI and significantly change the gap limit to, let's say, 100 000 addresses. I then receive BTC to my 999 999-th address and want to send them somewhere else. Will I be able to sign such transaction in TREZOR?

The question is, basically, does changing gap limit in Electrum or getting addresses beyond gap limit in Bitcoin Core HWI "getkeypool" generates extra private keys on TREZOR itself? And is such behaviour the same with all hardware wallets?


texts: Tax implications in Canada of buying and selling Bitcoins?

texts:
What taxes should be paid in Canada on Bitcoin transactions? Has anyone gotten official advice on this?

Is it relevant whether the Bitcoins were mined, received as payment for services, bought and then sold for a profit, or freely donated?

Is it relevant whether the Bitcoins are exchanged for CAD or exchanged directly for goods?

Is it relevant where geographically the buyer and seller are?


texts: Does Bitcoin Core still use "Bitcoin seed" in addition to a seed like stated in BIP 32?

texts:
In BIP 32 it's stated that a Master Private key is generated by hashing the concatenation of a random seed and the string "Bitcoin seed". And is like so in the example implementations.

But I couldn't find such string on Bitcoin Core's codebase. Is the seed just hashed directly to form the Master Key and Master chain code?


texts:
Most of the time that a regular user gets introduced to the concept of mining, they're immediately non-incentivized by the community and also by the high-cost of hardware compared to the actual reward.

With the steady difficulty growing and the environment around mining getting more competitive, it's pretty much a highly-specialized task where only large corporations with enough connections to buy cheap mining hardware can actually make an investment out of mining. Not the regular user.

If we fast-forward a couple of years I see this becoming more and more centralized and only few organizations will be able to actually afford mining.

My question is, how do we keep it decentralized and not resort to a situation where the power of the entire network resides only within few large corporations?


texts:
I I have a GekkoScience Compac BM1384 bitcoin miner that I am trying to get working with CGMiner on my Raspberry Pi. It is really annoying though, as it doesnt detect any devices on startup. However, when I go into USB management and select I it lists my bitcoin miner and it says "inactive". But when I try to enable it it says "invalid selection'.

Any suggestions?
Thanks,
BytePhoenix


texts: Check wallet address balance programmatically in PHP using Blockchain wallet api

texts:
I'm tyring to fetch my wallet balance programmatically using the Blockchain wallet api. Currently I was expecting that a simple api call to https:/blockchain.info/merchant/$my_guid/balance?password=$my_blockchain_password would have returned the value but it currently returns this page.

Is there something I'm not doing correctly?


texts:
if the winning miner takes the 12BTC+fees, unless you own the biggest mining operation out there, or are not a member of the biggest pool, why bother mining, if there is no prize for second place?  does the randomness still ensure the smaller pools get lucky  just enough to keep them interested in mining BTC?

the link below claims the massive Bitmain solves only 3 blocks a day ?  what could a smaller operation/pool hope to achieve? thanks

https://coincentral.com/the-top-5-largest-mining-operations-in-the-world/


texts: Recovering a Bitcoin Key Made From Rolling Dice

texts:
So a few years ago I created a private key by rolling dice.  Following the instructions from bitaddress.org, I rolled a dice 99 times and entered the string into the bitaddress.org.  Rather than storing the private key in WIF or HEX, I wrote the 99 digit string of dices rolls.  However, I changed some of the dice rolls to obfuscate the true private key if someone else stumbled upon the 99 digit numbers.  Now I can't remember which digit(s) I changed.

Using Python libraries, I've been trying different combinations/permutations of the 99 digit number.  Stuff like what if I swapped two positions or straight replacement of one or two digits.  No luck.

Any ideas?  How fast can I create keys and check if my key matches my bitcoin address?  Python libraries that I have found let me check about 10 permutations a second.  How much faster can I do with C?


texts: I see the block chain is stored according to the block chain format specification.  But I also see there is a database, which is currently a leveldb database.  Why is the block chain stored in two different ways?  Seems redundant.


texts: How do I use Vanitygen on Fedora 20? (openssl restrictions)

texts:
I have seen several methods for building bitcoin from source on Fedora, but I have not seen corresponding information for vanitygen.
It builds, and it starts up, but then it gives me the error:
"pattern.c:164: vg_exec_context_init: Assertion `vxcp->vxc_key' failed."
Of course, the cause is easily searchable: the Fedora implementation of OpenSSL does not include the algorithms that bitcoin depends on. Bicoin got around this, but vanitygen does not seem to be able to.
I downloaded and built the most recent version of OpenSSL from their website.
Using "make -rpath [path to the openssl I built]", however, does not change anything.

So my question is: How do I get vanitygen to point to my OpenSSL rather than the default OpenSSL? I don't want my entire system to use the custom OpenSSL because I trust the Fedora implementation more than the one I downloaded; however I don't intend to use the generated addresses for more than small bitcoin amounts, so they don't have to be as safe.

References:
How do I build Bitcoin in Fedora 18?

EDIT: For reference, the procedure referenced in the accepted answer below is:

NOTE: In both this and the accepted answer below, REPLACE openssl-1.0.1g WITH THE LATEST VERSION OF OPENSSL. 1.0.1g may have security flaws that are patched in future versions - it is current as of this writing, but probably will not be in six months.

mkdir ~/devel
cd ~/devel

wget http://openssl.org/source/openssl-1.0.1g.tar.gz
tar xfz openssl-1.0.1g.tar.gz
cd openssl-1.0.1g

./config --prefix=/opt/openssl-1.0.1g zlib-dynamic shared
make

sudo make install_sw


texts:
base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,176);

I need prefix L , but i cannot find how do this, please do not post link to prefix list bitcoin , it's only for address prefix.

i search all google end find noting.


texts: Is there any difference in pool mining with gash.io over slush?

texts:
I am new to the crypto-coin mining. If I am mining with my own hardware, is there any difference if I join slush or gash.io? Any difference in payment? There are lot of posts that says to stay away from gash.io because of the 51% share but currently they contribute around 34% only. Should we worry about that? The thing about that is more like if everyone started to mine using gash.io it will become centralized which looses out the decentralized nature of Bitcoin right?

Also, there is the CEX.io which provides GH/s for certain BTC. But since the difficulty increases over time, the GH/s value reduces. The GH/s will mine forever but wouldn't there be a time where that power cannot do any significant mining? Isn't the case with custom hardware too? Can you elaborate on that.


texts:
I am trying to sort out the use case of a published funding address on a web page, to which everyone can spend. Internally in our company, I want to avoid, that a single person can spend these funds. It shall require  more than one signature, to be able to spend the funds. I had the idea to use a multisig address, but this seems to be unsuccessful. The many stackexchange links don't cover this scenario, they all seem to cover how to spend from msig addresses...

When using a multisig adress, it looks like spends to this address requires the redeemscript. All examples I found use the redeemscript. So this is somehow a no-go for a multisig address on a webpage?

What I have done so far:
- I was thinking that "people" could send to the msig adress from a normal wallet (aka P2PKH script). That doesn't work out, as the pubkey script wouldn't find "true" on the stack. Given a standard pubkey script would require s.th. like this:

    DUP     HASH     PKH     EQ_VFY CHK_SIG
     |       |        |        |      |
     |       |        | PKHASH |      |
     |  PK   | PKHASH | PKHASH |      |
PK?  |  PK   |   PK   |  PK    | PK   |
SIG  |  SIG  |   SIG  |  SIG   | SIG  |  TRUE/FALSE

The first column (SIG and PK?) being the sigscript. For the multisig address there is no public key in the first column. For sure I could play with the redeem script at the very beginning, and hash it, to satisfy the "OP_EQUALVERIFY". But then the script wouldn't terminate "TRUE" at the end, cause it would leave the sig and a "hashed" hash on the stack.

I could publish the redeemscript. Disadvantage: this makes the user experience difficult
I could use a std. P2PKH address, and "forward" regularely the funds from the webpage P2PKH address to a multisig in the background. Disadvantage: with current fees, nearly idiotic, when only small amounts are spent. (Yes, I could write code to collect until spent amount >= tx fees ...)

Is there an easy (more intelligent) way to receive bitcoin payments on a website, that come with a condition to be spent only with multiple signatures?


texts: Why is a transaction with outputs of less than ฿0.00005460 rejected?


texts: Why does the blockchain keep transaction history rather than balance?

texts: The blockchain is very large and takes a lot of time to download to a client. Apparently, the only thing we need from the blockchain is the balance of each "user" (- public key). So, instead of keeping the entire blockchain, we could keep a smaller ledger that only contains the balances. Why isn't this done? What are the advantages of keeping the entire sequence of transactions?


texts: Automated FIAT Transfer to bank from Exchange

texts:
is it possible to trigger an automated wire to a bank account with an exchange platform?

we do want to make a couple of transactions a day depending on the bitcoin trading price based on rule sets.

from our wallet --> send to exchange --> automated process to sell into EUR --> wire send to Bank

any ideas?


texts: Do we have failed transactions in bitcoin?

texts:
I was checking the failed transactions and gas used in Ethereum: https://blockchair.com/ethereum/transactions?q=failed(true)
Do we have similar transactions in bitcoin that I can compare with?


texts: What is the algorithm that adjusts the difficulty of the proof of works in a proof of work based cryptocurrency?

texts:
For instance, Bitcoin has a proof of work based consensus algorithm, it's how Bitcoin chooses a node to create the next block in Bitcoin's blockchain. In this way the network is in consensus about the creation of the next block. Part of this block creation process is issuing the next proof of work to the network, and the consensus node, based off of the algorithm in question, may set a new difficulty on the proof of work. Bitcoin tries to keep this proof of work difficult enough but easy enough so that block creation times are around 10 minutes.

What is the algorithm that sets this difficulty?


texts: CLI: Generate a new private key, unrelated to any existing wallet

texts:
I have a wallet on an offline computer, which has too many backups on connected computers.

I would like to generate a totally new bitcoin address on the offline computer, and use it as a cold storage address. I will then sign an offline transaction from the wallet to that new address and be safe.

How can I create a new Bitcoin private key from the Bitcoin CLI, without using any existing wallet keys / addresses?

I've looked into getnewaddress, but it seems to be getting the keys from the keypool on the existing wallet.

Note - I know I can use bitaddress.org offline, but I would like to use the basic bitcoin-core tools for this one.


texts: How would cryptocurrencies be explained intuitively? I tried reading about bitcoin but most articles explain broad concepts ambiguously, and I want to understand the concepts so I could potentially make a cryptocurrency myself. So, here is my intuitive understanding of it. With online currencies usually there is a central service that steals some of the money when you make transactions? You don't want that so you directly do transactions from one person to the other, perhaps by passing a code that is worth value to someone else. OK, but this has problems because of double spending. A person cannot be sure if the currency has already been spent. So that's why there's databases that everyone has access to and everyone writes to that stores the amount of money everyone has. How would the databases verify that you are in fact doing the transaction and not someone saying that they are doing it? Through public and private keys, right. How that works is that each person has a private key that encrypts a specific code, and everyone has access to the public key that is paired with the private key. If that code, when decrypted by the public key, is in the correct format, then it can be verified who is making the transaction, because nobody else has the private key. But the code that needs to be decrypted must be different every time because if it's the same every time, whoever sees the code can use it to spend money. So maybe you make a rule that when you decrypt the code it has to form the current date to verify the transaction. The public key would be stored in the database with the corresponding amount of money connected to the public key. Also when you make the transaction you say which public key you want to give money to and which public key you have, and how much money you want to give. A lot of people's computers verify the transaction so it's safe. Why is mining even necessary? I might just be dumb because I don't have much cryptography experience, I do have some programming knowledge however.


texts: How to verify Bitcoin Core Release Signing Keys

texts:
I use Gpg4win but I don't know the step to verify the Bitcoin Core Release. can you give me the instruction how to verify released?

i git this resolte
C:\WINDOWS\system32>gpg2 --keyserver pgp.mit.edu --recv-keys 0x90C8019E36C2E964
gpg: conversion from utf-8' toCP720' not available
gpg: requesting key 36C2E964 from hkp server pgp.mit.edu
gpg: key 36C2E964: "Wladimir J. van der Laan (Bitcoin Core binary release signing key) " not changed
gpg: Total number processed: 1
gpg:              unchanged: 1


texts: Will my wallet be extended or replaced when I recover another wallet in Breadwallet?

texts:
Will my current balance combine with the balance on the other wallet I want to recover?

Or do I need to empty the wallet on my phone before recovering the wallet that was on my old phone?


texts:
Im currently working on exchange program. Just a problem during exchange process. An example, we have an SELLING LIST which list down all trading and selling of bit coin. So, in the meantime, there will be a tons of buyers to see the most appropriate and cheap sales. Give an example that there is one items from the Selling List that selling 1BTC for 1USD, so every buyer will immediately click on the item to buy the item. Hence, the question and issue is here,

Is there any effective way to tackle our program to avoid from crash as caused from multiple user clicked and accessed the item on the same?
I'm thinking about FIFO on the user access. Is there any more efficient way to tackle this issue?


texts:
I've got a wallet with bitcoin in it that I've had since 2011 or earlier. I was just claiming XLM using my receive addresses and the total XLM I received is about 75% of what I should have.

I checked every receive address on blockchain.info and the total btc is about 75% of what I have.

I'm not sure what to do from here.

edit: For the past few years I've had x bitcoin... the blockchain is rebuilding on my wallet right now and I'm really worried somehow I now have 25% fewer btc... wtf. I have a year and a half left to catch up on but a major receipt of btc was two years ago. I see that in my wallet but nothing else.... still 25% missing..


texts: How to generate addresses for a rudimentary BTC transfer app

texts:
I am a student studying web development at a prominent bootcamp in the United States. For my capstone project, I have decided to try and build a fairly simple application wherein one authenticated user can send an amount of BTC to another user (I described to my teacher as a bottled tipping platform). To do this, I am using the Coinbase API. While this sounds simple in theory, there are many points at which I am worried about tripping up.

Conceptually, I have been facing a dilemma about how the user's wallet will interact with the app. My initial impulse was to have the user plug in an external wallet when they created their account. In order to transfer from one user to another, the payer would send payments to a central wallet (for which I set up an OAUTH2 application), which would in turn send the coin to the payee. Under this paradigm, the technical messiness of actually creating the wallet could be avoided and the focus could be on the actual transfer of BTC. As I read the documentation, however, I lost confidence in the feasibility of my approach. Specifically, I was unsure of how I would go about generating addresses from both the payer and payee, a core part of the transfer process. Is my conceptual approach even possible? If it is, how would I go about getting the addresses from the payer/payee and pass them to the central wallet?


texts: Why a Bitcoin transaction that refers its own output as an input is computationally infeasible?

texts:
It was asked to us as in an assignment : Explain why it is computationally infeasible for anyone to generate a Bitcoin that refers its own output as an input.
Inspite of searching throught various resources,I was unable to find a satisfactory answer to it.


texts: Are there any transaction-related artifacts left in the database?

texts:
Bitcoin writes to some log files (bitcoin/*.log and bitcoin/database/log.nnnnnn )

Are these (and everything else other than wallet.dat) clear of any information that would allow a forensic investigation to determine which addresses a bitcoin installation had sent or received?

Reworded question from:
 - http://bitcointalk.org/index.php?topic=63488.msg743339#msg743339


texts: Sent Bitcoin Cash to a Bitcoin segwit address by accident on my Ledger Nano S

texts: Stupid but I sent bitcoin cash to a bitcoin segwit address I own on my Ledger Nano S. They are not shown in either wallet. Did I lose them or is there a way to get them back?


texts: bitcoin-cli could not locate RPC credentials

texts:
I'm running a bitcoind 0.16 and it seem working, blockchain in sync etc..
I've used the "new" rpcauth, which is non deprecated so kind of referennce as explained here: https://github.com/bitcoin/bitcoin/blob/v0.16.0/contrib/debian/examples/bitcoin.conf. I've generated the rpcauth line and the password with
./share/rpcauth/rpcauth.py bob

Copied the rpc line in the ~/.bitcoin/bitcoin.conf file and stored the password elsewhere. The conf file have this [rpc] section:

server=1
rest=1
rpcauth=bob:b2dd077cb54591a2f3139e69a897ac$4e71f08d48b4347cf8eff3815c0e25ae2e9a4340474079f55705f40574f4ec99

I run

./src/bitcoin-cli get blockchaininfo -rpcuser={...} -rpcpassword={...}

The answer is:

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

It's like the cli can't read the rpc credentials from the command line. It's not saying "credentials are wrong". Also the conf file is the correct one so...

Any clue?


texts: How to setup bitcoin network using regtest?

texts: My question might seem really basic , but I am looking for help as to how can I setup bitcoin network using regtest?


texts: Cannot make valid Bitcoin Cash transaction

texts:
I've been way in over my head hacking around in various Python Bitcoin libraries. From what I understand, input public keys have to be compressed to be accepted. Is that correct? I have an uncompressed address that I am trying to send funds from.

If I compress the input public key it shows the input address as the compressed version which shows no balance in block explorers. However, I get a Signature must be zero for failed CHECK(MULTI)SIG operation error when I try to broadcast this transaction.

This is the transaction: 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

If I do not compress the input I get this error: Script failed an OP_EQUALVERIFY operation

And this is the uncompressed key transaction: 0100000001edc990f08c1ddd5102dfc7f4af32e7927a14fd8d0bc9996725f38ede549b91f8010000006b483045022100ed2a0f6644ff41b9baba8c35356a414b3da24edaea1bf68396efc7ffcbc5b8e902207b1b22c6201c2e4975cbbfc869632d4a2c89b46477b71ef6f875f1c844346d4d412103e1c33577152151109fe5e02c600f386fda865594c1b989ce0fcfbc0fb0b144a2ffffffff0238300000000000001976a9141a586975175967c83e2b90422bcd8af9a623156288acfdc20d00000000001976a91470fb690a177e8721098d90284ab3c3304ee19cd588ac00000000

Am I correct in understanding that OP_CHECKSIG comes after OP_EQUALVERIFY, so the first transaction is closer to being valid? And thus all I need to do is fix the signature? Or is there something else I'm missing?

Thank you!


texts: Is it possible to use Bitcoin-core for multisig? Can it handle change addresses?

texts:
I have tried to import three xpub in a watch-only wallet as keypool with importmulti and a multisig output descriptor and to fill the first address with some BTCs. When I try to spend the newly created multisig UTXO, creating a walletcreatefundedpsbt, there's an error instead of creating a psbt.
For context, my intention is to protect the wallet with three Hardware wallets. I' m doing this tests in regtest.
Here are the details:
I have generated three xpub:

pubkey1 tpubD6NzVbkrYhZ4YKMs9TvzemC7FaKYnNxESKvYN9V6PDnDwBXrHQk97rNC71fCXxyobFgcZDfesc5ThCMkUYjA5edd8J1qUQoR4P3kPywrGw6
pubkey2 tpubD6NzVbkrYhZ4X2MQYSo3wVWBPGjV3fUcN4DywfR2ZcM1F56A2bapN54YJqa47yDvwuTajWqkBHxRmdGHLQJj5ae7V1NXDN2JP8AKcyurzsa
pubkey3 tpubD6NzVbkrYhZ4XYeFSXzJ9fFu91eiSEpanzbhifxuSAb7m4piv9QxXsHi2a9jnspQpeKpnpdsyNhoMWb6traBXErL9TPjP3EKnPVFuzyv7Ed

then I have created a disable_private_keys wallet.

bitcoin-cli -regtest createwallet multi

then imported the output descriptors in the new wallet.

bitcoin-cli -regtest -rpcwallet=multi importmulti [{"desc": "wsh(multi(2,tpubD6NzVbkrYhZ4YKMs9TvzemC7FaKYnNxESKvYN9V6PDnDwBXrHQk97rNC71fCXxyobFgcZDfesc5ThCMkUYjA5edd8J1qUQoR4P3kPywrGw6/1/*,tpubD6NzVbkrYhZ4X2MQYSo3wVWBPGjV3fUcN4DywfR2ZcM1F56A2bapN54YJqa47yDvwuTajWqkBHxRmdGHLQJj5ae7V1NXDN2JP8AKcyurzsa/1/*,tpubD6NzVbkrYhZ4XYeFSXzJ9fFu91eiSEpanzbhifxuSAb7m4piv9QxXsHi2a9jnspQpeKpnpdsyNhoMWb6traBXErL9TPjP3EKnPVFuzyv7Ed/0/*))#hnd2wec3", "internal": true, "range": [0, 10], "timestamp": "now", "keypool": true, "watchonly": true},{"desc": "wsh(multi(2,tpubD6NzVbkrYhZ4YKMs9TvzemC7FaKYnNxESKvYN9V6PDnDwBXrHQk97rNC71fCXxyobFgcZDfesc5ThCMkUYjA5edd8J1qUQoR4P3kPywrGw6/0/*,tpubD6NzVbkrYhZ4X2MQYSo3wVWBPGjV3fUcN4DywfR2ZcM1F56A2bapN54YJqa47yDvwuTajWqkBHxRmdGHLQJj5ae7V1NXDN2JP8AKcyurzsa/0/*,tpubD6NzVbkrYhZ4XYeFSXzJ9fFu91eiSEpanzbhifxuSAb7m4piv9QxXsHi2a9jnspQpeKpnpdsyNhoMWb6traBXErL9TPjP3EKnPVFuzyv7Ed/0/*))#6jvyd6m3", "internal": false, "range": [0, 10], "timestamp": "now", "keypool": true, "watchonly": true}]

I have filled the first multisig address:

bitcoin-cli -regtest -rpcwallet="" sendtoaddress $(bitcoin-cli -regtest -rpcwallet=multi getaddressesbylabel ""|jq -r 'keys|.[0]') 10
bitcoin-cli -regtest -rpcwallet="" generatetoaddress 1 $(bitcoin-cli -regtest -rpcwallet="" getnewaddress)

but then, when I do:

bitcoin-cli -regtest -rpcwallet=multi walletcreatefundedpsbt [] "{\"$(bitcoin-cli -regtest -rpcwallet="" getnewaddress)\":0.5}" 0 "{\"subtractFeeFromOutputs\":[0], \"includeWatching\":true}"

I get:

    error code: -4
error message:
Can't generate a change-address key. No keys in the internal keypool and can't generate any keys.

What am I doing wrong?

Is there a way to manage the internal keypool so to have a multisig whatch-only wallet I can use with two or three HWW?

Thank you.


texts:
With Mt.Gox probably going insolvent/broke in these days, how safe is my USD account balance with Bitstamp? Is Bitstamp as a company registered with some financial institutions? Are customers USD deposits insured? I only want to consider security from the financial point of view and not my account security (strong passwords, two-factor authentication etc. - is a personal responsibility IMHO).

I guess I would lose all my USD balance if the company goes broke?


texts:
I read about Input and output scripts on the wiki here:

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

Let's say, I use my Bitcoin - QT Program, I go to "Send Coins" tab, enter a Bitcoin Address, BTC amount and then click Send.

Is the output script generated by my program?

For an output script, we need the Value, The destination Address and the scriptPubKey. My client program has all this data.

scriptPubKey refers to Public Key of? My public key or the person I intend to send the Bitcoins to?

So, now, once the output script is formed, is it broadcast over the Bitcoin Network?

Where does the Input Script come from?

the scriptSig in Input Script refers to the Public Key and Signature of whom?

When I am sending Bitcoins to a Bitcoin Address, the input Script is automatically generated by what?

Even though the wiki gives details about Input Script and output Script, I was unable to correlate it to a real time scenario where one person sends BTC to another.


texts:
Where can I find information on running a Gridseed miner on Mac OSX? Either BTC and/or LTC.

I'm looking for rather consistent information, by this I mean instructions with links that point to the software that works with the instructions or at least specifies the version of the software. One problem I see is that instructions are created and then the software is updated and no longer matched the instructions.


texts: So about two weeks ago i sent bitcoin to a friend, and it was confirmed but in the summary it was listed unspent, he claimed not to have received. I was really confused since then, now this morning i check again and i noticed the status has changed to ‘spent’. Now i am more confused. Does that mean he has finally recieved it? *i tried contacting blockchain support but i didnt get a response


texts: Is there any argument to be passed to CGMiner\AntMiner S2 to reserve amounts of hashing power for specific workloads?

texts:
I have an AntMiner S2 (1TH/s) and I'd like to mine both on BTC and NMC.
Would that be possible, for instance, to use 50% of power just for BTC workloads and the other 50% for NMC?
EDIT:
What exactly is the Intensity parameter?

ckolivas says:
Intensity is the amount of work in one go the GPU has to do before it can return its results.

But I'm still confused: what is it in practice?