texts: Getting paid by BitCoin on my website using Credit Card

texts:
Somehow, I think it's a trivial question yet I couldn't find an answer for it.

I have a website that gives online services. Like Image hosting etc'.

I want to receive money in BTC, but most people yet does not have BTC. So I thought, maybe they could pay using CreditCard, it will be converted to BTC and I will get it in BTC.

Is there a service that can do that for me ? Like a pay-pal on my website that people put in their CC details and I will be paid in BTC. I am aware that there will be a fee for that.

Thanks.


texts: Do bloom filters protect against a persistent eavesdropper?

texts:
As far as I understand it, bloom filters can be defined with some target hashes and false-positive rate. When filtering the blockchain, all of the target transactions are guaranteed to be found, but many false-positives will also be returned to the client by design.

Suppose that an attacker is able to monitor many bloom filter specifications sent by an SPV client to its peers. Will he be able to eventually eliminate all false positives by performing subset matching on all transactions matching the filters?

As an example, let the set of all transactions be the integers from 1 to 100, and suppose that a client is interested in the transactions 4, 8 and 15. The first time he connects to the network, he transmits a bloom filter matching (1, 4, 7, 8, 15, 27, 44, 73); the second time, his filter matches (3, 4, 6, 8, 15, 27, 66). An attacker would immediately be able to narrow the possible transactions down to (4, 8, 15, 27); after several more invocations, he would then find the correct answer.

Am I misunderstanding how bloom filters work (e.g. the false positives do not change between connections), or is this a theoretical or even practical concern?


texts: What does this comment in Chainparams.cpp mean?

texts:
There is a comment in the Bitcoin source code under src/chainparams.cpp

/**
 * Build the genesis block. Note that the output of its generation
 * transaction cannot be spent since it did not originally exist in the
 * database.
 *
 * CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
 *   CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
 *     CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
 *     CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
 *   vMerkleTree: 4a5e1e
 */

What exactly does this value refer to?

coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73


texts: Bitcoin difficulty re targeting in case of catastrophic hashrate drop?

texts:
I do understand that the mining difficulty changes every 2016 blocks :

next_difficulty = (previous_difficulty * 2016 * 10 minutes) / (time to mine last 2016 blocks)

But how is difficulty changes if suddenly 90% of hash rate disappears* ?
I would be very grateful if someone could kindly point me to the class in sources.

*recent BCH fork had difficulty adjusted quicker than 2016 blocks.

P.S.
Should I be looking at

unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params)

in pow.cpp ?


texts: Hack/Use a Butterfly bitcoin miner as gaming pc

texts:
How can I hack & build upon (i.e. add DVD drive, USB reader, etc.) a BitCoin miner like (Butterfly Jalapeño).

Everyone tries to use their gaming computer as miner but I want to venture & try to get insane performance by using parts of a miner & build a PC from it.

Or it is impossible?


texts: Under what circumstances does bitcoin-qt ban a peer?

texts:
Under What Circumstances Will Bitcoin-qt Ban A Peer?

In my bitcoin-qt wallet, I am noticing that often there are a lot of banned peers.

Sometimes I have as many as 10 peers banned within the wallet, but I am doubtful that all of these peers are acting maliciously.

I'm curious, what are the circumstances under which the QT wallet will ban a peer?


texts: How Blockchain transaction verification takes place?

texts: How does each transaction verifying node come to know if the sender has enough amount in its wallet to transfer to the receiver or not? How are Blockchain transactions validated?


texts:
I just got this message: "Alert key compromised, upgrade required".
 How urgent is this? Am I in danger of losing my Bitcoin?
 What do I do?


texts:
I have a friend in the USA who can send me bitcoins. The idea is to sell the bitcoins in India and wire him back the money from the sales proceeds in India.

What are the tax implications on the sale of bitcoins in India?
What reason for remittance should be stated on the wire transfer?

I believe I can sell the bitcoins through Indian bitcoin companies like unicoin, which transfer the money into your account once the bitcoin is sold.


texts: What are the steps in building bitcoind on Mac OS X 10.6?

texts:
Following the instructions in build-osx.txt (which seem sadly out of date) leaves me without a file named libboost_system.a.

Here is how I built boost:

% cd boost_1_42_0
% ./bootstrap.sh
% ./bjam architecture=combined address-model=32_64 macosx-version=10.6 \
    macosx-version-min=10.6 link=static runtime-link=static -a \
    --toolset=darwin --prefix=/Users/`whoami`/bitcoin/deps install

I had to edit the makefile.osx to add some include paths, but I could not find libboost_system.a. What am I missing?

Also, I needed to compile OpenSSL because OS X only comes with dynamically linked libraries.


texts:
Venezuela is about to launch its own Petro cryptocurrency

Could the chaotic economic scenario the country have lived be a good chance to  change the usual  currency to a criptocurrency?

I mean, What can significantly mean success or failure in this case?


texts: Can a private key enumeration attack be used to steal bitcoins?

texts:
Let's consider the following algorithm

enumerate all of the private keys
for each of the enumerated private keys, generate the relative public key and verify whether there is any unspent coin associated with that public key
if there is any unspent coin, transfer those coins to an address owned by the attacker

Would an attack like this work?


texts: Segregated witness soft fork: how is the funding Tx made "ANYONECANSPEND"

texts:
Reading the BIP:

https://github.com/bitcoin/bips/blob/master/bip-0142.mediawiki

I see that the scriptPubKey in a transaction that funds a segwit redemption is the same as a normal P2PKH but merely prepended with OP_0.

Is this opcode what tells older clients that the Tx is "anyone can spend" meaning that there will be no signature data in the redemption Tx?

Of course upgraded nodes will know to look for the actual scriptSig in the witness data to verify the Tx. But how does this OP_0 fool old nodes into ignoring the scriptSig on the redemption Tx?


texts:
I'm trying to learn a few things about the API. I've managed to send coins on testnet via wallet.sendCoins(Peergroup,Address,BigInteger) so I don't think I have a network problem.

Here's what I'm trying to do, assume my wallet has the transaction, a Peergroup already exists and is connected, and the blockstores and such exist:

    Transaction tin = wallet.getTransaction(
            new Sha256Hash("015a7cff7048b622315fe610e9e72347420a5528b938bffc931ddacf24b9ce88"));

    System.out.println("Input transaction: " + tin.toString());

    Transaction t = new Transaction(nwp);

    t.addOutput(Utils.toNanoCoins(4, 10), new Address(nwp, "mmhmMNfBiZZ37g1tgg2t8DDbNoEdqKVxAL"));
    t.addOutput(Utils.toNanoCoins(4, 0), new Address(nwp, "mrtUDRNFuwVPrKgwaGLuc3VvRCVYbayLkC"));

    t.addInput(tin.getOutput(0));
    p.broadcastTransaction(t);

As you can see, the transaction is trying to spend a specific previous transaction of 8.10 incoming by sending 4.10 back to the faucet and 4 back as change.

Unfortunately it doesn't propagate on the network. What do I need to do? I've been trying to follow the code in Wallet.java, but it's pretty complicated. From what I can see it's some checks on the amounts, coin selection, and locks on the coins to be used. Attempts to sign the transaction cause a warning (already signed) and a crash.

Can someone let me know what the minimum necessary steps for creating and sending this transaction are?


texts: Is buying and selling bitcoin in large volumes possible, or wise?

texts:
I'm asking because I think it could be a decent investment, but on clarkmoody the volumes aren't very large.

Which could mean that bitcoin is only useful in small volumes, and that larger transactions (i.e. $ 5000 - $ 10000) will have to much of an influence on the price to be considered a wise investment (i.e.: you wouldn't be able to buy/sell everything at once without the price dramatically rising/falling). Any ideas/suggestions from the experts?


texts: How can I clone bitcoin 0.16.1 version (not the latest one ) with git command

texts:
this is the version that I want to clone :

https://github.com/bitcoin/bitcoin/releases/tag/v0.16.1


texts: How do i find my private keys in my blockchain.info wallet?

texts:
I've tried numerous times to find private key in settings/addresses, but can't find any.

My question is not like the other problems here, because i cannot even see my private key. I can find xPub extended private key on my default wallet. But is that the same thing?


texts: Unspendable outputs vs Black Hole address

texts:
On the Script page of the Bitcoin Wiki, in the "Provably Unspendable/Prunable Outputs" section, it gives an example of a script which would make that output of the transaction unspendable. In the example they give,

txid eb31ca1a4cbd97c2770983164d7560d2d03276ae1aee26f12d7c2c6424252f29

The unspendable output has zero value so the entire input amount goes to the miner of the block.

But if that output had been given some value of bitcoin, would I be correct in assuming those bitcoins would be provably unspendable forever? If that is the case, what is the need of a black hole address like the bitcoin eater? Couldn't bitcoins be provably "destroyed" simply using such an unspendable script transaction output?

Thanks


texts: How to turn off "change" address in bitcoind?

texts:
I would like to keep backup of my wallet on paper, but that's impossible or at least impractical when the bitcoind keeps creating new addresses for "change". I know it is possible in theory to do it by sending the change back to the sending address. And I know there are privacy implications when doing this. But I care more about security than anonymity in my case.

Is there an option to turn off "change" addresses in bitcoind (the original Satoshi client)?


texts: How to use bitcoind with CUDA-ready box?

texts:
I am not asking for mining (which is all the information I could find on the net). I am asking for the regular bitcoind daemon, looking for having a full node with a reasonable high performance per watt.

My use case is: I have a Jetson TK1 board and would like to use it. However, I have seen that bitcoind tends to saturate the CPU and I would prefer to take advantage of the CUDA cores (both for performance and for energy consumption).

My google-fu is weak, and there is a lot of information about mining (which I am not interested in) but not on this specific application.

I was considering performing a fork of the bitcoin source at GitHub, but it seems a huge task and I am not sure if the community will be as interested as I am. And maybe there are efforts on it, which I could not find.


texts: How to select minimum difficulty when mining with Slush Pool

texts:
I am mining on a single Antminer S9 with Slush Pool.

There is a setting called "minimum difficulty":

When I read their manual, item #8 states

The pool automatically assigns difficulty that corresponds to the hash rate of your miner.

My scoring hash rate and hash rate are consistent with what the manufacturer of my mine advertises: 13.5 TH/s

and my default difficult is set too be 128.

However when I proceed reading their manual further I find that minimum difficulty should be set at 1024 for 1TH/s and then increases linearly with the hashrate.

According too the table my difficulty should be 13 times 1024 which is 13312. This is way higher than the pool determined 128.

What should I set the minimum difficulty be?

I tried to understand what minimum difficulty is but I was unable too find a clear and simple explanation what this number represents.


texts: How come this formula predicts more than four years to the next halving?

texts:
So I was looking at https://www.binance.vision/halving and it shows that their formula for halving is

(Halving block height - Next block height) * Average time between blocks - estimated time until the next block

However, their countdown seems off as it exceeded 4 years, is this accurate?
What's the correct formula to calculate countdown for halvings?


texts: When increase transaction fee three times in few minutes - transaction had an attempted double-spent?

texts:
I make transaction from my wallet - send BTC.
After I send, I increase transaction fee three times, in a few minutes.
Now I see - Status: conflicted with a transaction with 21 confirmations
I use Bitcoin Core version v0.18.1 (64-bit)
In block explorer I see that this transaction had an attempted double-spent.
What can do in my case?


texts:
I have an address mpc1rKeaMSCuQnJevMViLuq8uWjHwgdjiV
I check it via json rpc and get balance = 4.6 with 6 confirmations
When I check http://blockexplorer.com/testnet/address/mpc1rKeaMSCuQnJevMViLuq8uWjHwgdjiV
I get nothing.. is it OK ?


texts: starting alphad what is the correct rpcconnectport

texts:
following the instructions in the alpha-README.md file on GitHub
in step number 2, to start alphad it is suggested to do:

./alphad -rpcuser=$RPC_USER -rpcpassword=$RPC_PASS -testnet -rpcconnect=127.0.0.1 -rpcconnectport=18332 -tracksidechain=all -txindex -blindtrust=true -daemon

my question is about the rpcconnectport=18332
why 18332 instead of 4241?  like in step 5


texts: Convert between String/Hex/Byte in Java for sha256 - wrong format?

texts:
I am trying to convert a bitcoin address and have the following code from here (Calculate Segwit address from public address, 2nd answer):

Step1: $ printf 1L88S26C5oyjL1gkXsBeYwHHjvGvCcidr9 > adr.txt
Step2: $ printf $( cat adr.txt | sed 's/[[:xdigit:]]\{2\}/\\x&/g' ) >adr.hex
Step3: $ openssl dgst -sha256 -binary <adr.hex >tmp_sha256.hex
Step4: $ openssl dgst -ripemd160  <tmp_sha256.hex
## result should be: 56379c7bcd6b41188854e74169f844e8676cf8b8

Now I want to do this in Java. I currently have the following code. No matter what I try, I dont get the correct result. :(

String address = "1L88S26C5oyjL1gkXsBeYwHHjvGvCcidr9"; // step 1
System.out.println("address: " + address);
String addressHex = toHex(address);
System.out.println("address hex: " + addressHex);
byte[] addressBytes = addressHex.getBytes(StandardCharsets.UTF_8); // step 2
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] hash = digest.digest(addressBytes); // step 3
RIPEMD160Digest digest2 = new RIPEMD160Digest(); // steps 4
digest2.update(hash, 0, hash.length);
byte[] out = new byte[20];
digest2.doFinal(out, 0);
System.out.println("result: " + bytesToHex(out)); // = 62ab42cba5d2632d1350fafb2587f5d2ece445d3
                                                  // should be 56379c7bcd6b41188854e74169f844e8676cf8b8

Output:

address: 1L88S26C5oyjL1gkXsBeYwHHjvGvCcidr9
address hex: 314c383853323643356f796a4c31676b58734265597748486a764776436369647239
result: 62ab42cba5d2632d1350fafb2587f5d2ece445d3

Can someone help me? I think the problem is somewhere doing the conversion String/hex/byte ...? I tried really hard, but cannot find the correct way to do it.

I also tried to convert the address to hex and after that to bytes, but doesnt work neither. :/

// updated post
... still doesnt show the correct result :/

// update2:

byte[] address = ("1L88S26C5oyjL1gkXsBeYwHHjvGvCcidr9").getBytes();
System.out.println("address byte array: " + address);
String addressHex = bytesToHex(address);
System.out.println("address hex: " + addressHex);
byte[] addressBytes = addressHex.getBytes();
MessageDigest digest = MessageDigest.getInstance("SHA-256");
byte[] hash = digest.digest(addressBytes);
RIPEMD160Digest digest2 = new RIPEMD160Digest();
digest2.update(hash, 0, hash.length);
byte[] out = new byte[20];
digest2.doFinal(out, 0);
System.out.println("result: " + bytesToHex(out));

Output

address byte array: [B@108c4c35
address hex: 314c383853323643356f796a4c31676b58734265597748486a764776436369647239
result: 62ab42cba5d2632d1350fafb2587f5d2ece445d3


texts: What would the expected block mining time be if 30% of the total network hashrate disappeared suddenly?

texts: Ignoring the economic reasons as to why this may or may not happen.  If for some reason the network hashrate suddenly dropped by 30% immediately after a difficulty adjustment and remained at that level until the next difficulty adjustment, how long would each block be expected to take to mine until the next difficulty adjustment.


texts: Is mastercoin a perpetual bitcoin machine

texts:
If Alice sends Bob one bitcoin on the mastercoin network, this transaction is technically implemented using a standard bitcoin transaction with a negligible amount.
Isn't that equivalent to creating bitcoins from thin air?


texts: Find Lightning node for channel creation based on amount and route

texts:
Is there a tool to identify a Lightning node that will accept a channel open request and that matches the two conditions below?

Accepts channel amounts of less than or equal to X.
Can route payments, directly or indirectly, to node N.

The scenario is I want to send a small payment to node N but it only accepts new channel requests with amounts much large than X.
My only solution at the moment is to use an explorer to find all the nodes N has channels with and then try creating a channel with each of them for X.


texts: Can a transaction have a single 0-value OP_RETURN as its only output?

texts:
My goal is to create a transaction that spends dust outputs to a miner. Since the goal is to reduce the UTXO set by consuming low value outputs, I do not want to create any new UTXO by actually sending Bitcoin to an address.

Is it valid to make a transaction with several inputs and only one single, zero value prunable OP RETURN output?


texts: How do Blockchain Explorers lookup wallets? [Balance]

texts:
How do Blockchain Explorers lookup wallet balances? Im trying to make my own explorer. For example Bitcoin-cli does not have a method (function) to lookup a wallets balance. listtransactions does not show balance.
Anyone with some know-how, can you link me anything? Im talking about Bitcoin but if you know how for other currencies, let me know please


texts: How to have my bitcoin-cli connect to an outside fullnode

texts:
I don't want to run a full node in my laptop. I rather want to install bitcoin-cli only and configure it to connect to an external full node. Is that possible?

If so, two questions:

where can I get a list of full nodes?
where can I record a full node from the above step in my bitcoin-cli

This is just for a quick test of bitcoin-cli. If there is other way to do this without setting up a full node myself, that works as well


texts: What is wrong with my ScriptSig? I get 64: scriptsig-not-pushonly

texts:
I currently try to create and sign transaction from scratch. I made it to construct and sign a transaction. If I verify it manually it looks good but using a "proper" wallet my transaction is refused:

error code: -26
error message:
64: scriptsig-not-pushonly

That's what I get from bitcoin-cli

My ScriptSig is: 4a304602210090c4fc2369cf225559c1141a1e9be3d7598f0fb7affe8a29f86e737972c7587a022100cbd8619ecae3baa40fdb565014fdac28a95deb90c0fcd4adcbd97d58d0e96f9801410442718de90a0a10f0cd10054ff4ab6037fd230c5d4b50c07eed0bc247e1e3dbd9ad3f4c65680396813bd96b0c2db5647e355082db34c7106a74337d51e5730f45

I would decode it as follows:

4a => length of signature, 74 byte

304602210090c4fc2369cf225559c1141a1e9be3d7598f0fb7affe8a29f86e737972c7587a022100cbd8619ecae3baa40fdb565014fdac28a95deb90c0fcd4adcbd97d58d0e96f98 DER signature

01 opcode SIGHASH_ALL

41 public key length, 65 byte

0442718de90a0a10f0cd10054ff4ab6037fd230c5d4b50c07eed0bc247e1e3dbd9ad3f4c65680396813bd96b0c2db5647e355082db34c7106a74337d51e5730f45 public key

Can you spot a problem with this ScriptSig?


texts: Do miners mine their own transactions or submit them to the network?

texts:
I am wondering how miners are behaving toward their own transactions. Do they send their own transactions to the mempool or can they process/confirm them directly?
I am assuming that the miners are interested or involved in sending and receiving of the bitcoins as well.


texts: Why does Bitcoin Core not support showing the prices in USD or other fiat currencies?

texts:
One of the major annoyances I have with Bitcoin is that the only wallet/client I trust to some degree, Bitcoin Core, for some reason only shows sums in BTC.
Every time I want to make a transaction, I have to copy and paste sums from it to my special, separate calculator to get how much money it is. And when it's time to make the transaction, and it displays the fee amount, I see it only as BTC. I then have to manually type the sum in (since it doesn't let you copy the fee part) to see how much the fee is.
This minor detail really causes a lot of frustration. I truly don't get why they won't just add this.
And I don't agree with those who would say that this would require it to rely on some central entity, etc. The Bitcoin network, transferring tons of data around the clock, could very easily be made to keep track of a small blob containing the top currencies' exchange rates against Bitcoin. It would not violate anyone's privacy to have that extra data shuffled around, and it would not be part of the blockchain, but simply the "RAM network", like all the other "communication signals". It's a very minor piece of data, and infinitely useful. It could even have multiple different ones and let you choose which one you want to use.
Why do they not want to add this feature?
PS: I'm not going to switch to a different wallet/client. Please don't suggest that.


texts: What happens to a transaction once generated?

texts:
I'm trying to understand how bitcoin works technically. I understand the blockchain, digital signatures etc ... I'm more interested in what happens to a transaction once it's "created".

Suppose Bitcoin only contains one transaction per block (to simplify). Basically:

someone create a transaction using its wallet
this transaction must be validated (check inputs, digital signature etc ...
a proof of work must be computed on the block hash
the the block is added to the blockchain

So I know miners are responsible to come with the proof of work. My questions are:

how does one node broadcast a transaction to miners ? Is it part of the P2P protocol ?
does miner check the transaction (digital signature, available inputs etc ...) ?
does miner directly submit blocks to the blockchain ?

This part is still confusing to me any help pointers to article would be great :)

Update:

In a P2P network, nodes are not connected to every other nodes. So let's say the network looks like this:

node1 <-> node2 <-> node3 (1 and 2 are directly connected and 2 and 3 are directly connected. 1 and 3 are connected through 2)

When node1 wants to broadcast a transaction for validation, it will only broadcast it to node2. Then node2 can eventually broadcast it to node3 to give him the chance to validate node1's transaction.

But, because we are in an untrusted network, nothing prevent node2 to validate the transaction without never transmitting it to node3 and thus, keeping mining fees for himself.

We could also imagine that node1 never broadcast it's unconfirmed transaction, do the mining work himself and only broadcast the validated block so it get "merged" into the blockchain.

How does Bitcoin deal with this situation ?


texts: Withdrawal of coins to Trezor did not happen, Where are my coins?

texts:
I set-up Trezor yesterday and withdrew coins from my exchange to store in the Trezor. I entered the address and conifrmed.
However, an hour later, Trezor said Network error. It was unable to receive the coins.
The address I entered is also not showing up on Trezor today.
How do I get my coins?


texts: How to sign a raw multisig transaction from an external private key

texts:
I am creating a 2-of-3 multisig wallet, where the 2 hot keys are external HSM devices.
I am using Bcoin to create my transactions.
After the transactions are created, I will send the raw transaction to an external application to do the signing.

My question is, which part exactly needs to be signed by the private key?

For example, this is my transaction:

{
    "hash": "e82c7bdfc864ab4d0592045dd86b81a438eeee77f8415c0a84e1aa0ea8e17786",
    "witnessHash": "e82c7bdfc864ab4d0592045dd86b81a438eeee77f8415c0a84e1aa0ea8e17786",
    "fee": 1000000,
    "rate": 4424778,
    "mtime": 1568880046,
    "version": 1,
    "inputs": [
        {
            "prevout": {
                "hash": "3b1dd17cc82e2ac43ba62bf8f1c6a0fe805df43911653d22c902571eb3a212ce",
                "index": 0
            },
            "script": "000000004c6952210209ad6cf408e41362fa175d5869e4561f1890c0d8d74353c86095fdecde34459721024a92aa3f883cc4438b75205555e517a4f7cc10ffd42517297a17821ae6f0bb8821037d2a259a52f62fee96fea072844139224fbd9027116ac7582025dd446fc73e3e53ae",
            "witness": "00",
            "sequence": 4294967295,
            "coin": {
                "version": 1,
                "height": -1,
                "value": 10000000000,
                "script": "a9144de6d3580732a7c7c2b1eb043cb1b89350c265fa87",
                "address": "38nvUMbXFdXDp4PTWvbohCbnPJuLUVwzXr",
                "coinbase": false
            }
        }
    ],
    "outputs": [
        {
            "value": 5000000000,
            "script": "a91481be67198d33319415d09b03f2dc2cfa4cdb42aa87",
            "address": "3DX3BhmdRGf5vYbtzHKzazGmZ7WgUkhFRk"
        },
        {
            "value": 4999000000,
            "script": "a9144de6d3580732a7c7c2b1eb043cb1b89350c265fa87",
            "address": "38nvUMbXFdXDp4PTWvbohCbnPJuLUVwzXr"
        }
    ],
    "locktime": 0,
    "hex": "0100000001ce12a2b31e5702c9223d651139f45d80fea0c6f1f82ba63bc42a2ec87cd11d3b000000006f000000004c6952210209ad6cf408e41362fa175d5869e4561f1890c0d8d74353c86095fdecde34459721024a92aa3f883cc4438b75205555e517a4f7cc10ffd42517297a17821ae6f0bb8821037d2a259a52f62fee96fea072844139224fbd9027116ac7582025dd446fc73e3e53aeffffffff0200f2052a0100000017a91481be67198d33319415d09b03f2dc2cfa4cdb42aa87c0aff6290100000017a9144de6d3580732a7c7c2b1eb043cb1b89350c265fa8700000000"
}

If you decode the script in the inputs it is:

OP_0 OP_0 OP_0 OP_0 52210209ad6cf408e41362fa175d5869e4561f1890c0d8d74353c86095fdecde34459721024a92aa3f883cc4438b75205555e517a4f7cc10ffd42517297a17821ae6f0bb8821037d2a259a52f62fee96fea072844139224fbd9027116ac7582025dd446fc73e3e53ae

As you can see there are 4 OP_0 placeholders to input the signatures.
Now my question is, which part of the transaction the external signing application should sign. Is it just the 000000004c6952210209ad6cf408e41362fa175d5869e4561f1890c0d8d74353c86095fdecde34459721024a92aa3f883cc4438b75205555e517a4f7cc10ffd42517297a17821ae6f0bb8821037d2a259a52f62fee96fea072844139224fbd9027116ac7582025dd446fc73e3e53ae
part?

Any reference is highly appreciated.
I have read https://en.bitcoin.it/wiki/Transaction and https://en.bitcoin.it/wiki/OP_CHECKSIG but I can't figure out for sure.
Thank you.


texts: Bitcoin Performance: What does Hashes/Second Mean?

texts:
Computing preimages (nonces) that satisfy a hash output with known property (minimum number of prefixed zeroes) is the foundation of bit-coin mining and block-chain validation. For this purpose, all available hardware, whether general purpose PCs and servers or custom ASICs that specifically target bitcoin mining, is rated for performance in terms of "Hashes/sec, Mega Hashes/Sec, or Giga Hashes/Sec".

Without specifying the length of the data  that is hashed, I find this rating of HW in terms of 'Hashes/Sec' to be vague at best. All hashing algorithms input messages of arbitrary length  and computed an fixed length message digest. So, a processing power that performs a "million hashes per second" over input blocks of length 100 bytes is not quite the same of another HW that can perform 'million hashes per second' with input blocks where the block length is 4 kilo bytes.

Questions:

What does it mean to say 'my HW can perform x hashes/sec'? Does each 'hash' refer to the block size of SHA256 algorithm, which is 512 bits?
Or, does a hash refer to hashing a block chain, whose length is highly variable subject to the transactions that define a block-chain?
Is there is a well known benchmark program that can measure the 'hashes/sec' supported by any piece of HW?

Without clarifying the above details & publishing a benchmark that everyone can look up to, vendors' claims of "Hashes/Sec" seems like a marketing ploy to me.

[Added Later]
I have a further question on the details of how a valid nonce is searched. As I understand it, the search is determined by 3 parameters

(a) The block header
(b) target string
(c) nonce

A representative pseudo code that searches for the nonce can be written as:

while (hash_256(hash_256(block_header, nonce) >= target_string) do

      nonce = nonce + 1

end_while

I have modeled the above pseudo code from this blog of Ken Schriff. It is not clear how this code models the 'difficulty' parameter. Above loop (as well as the one found in the blog) iterates through all nonce values from 0 through (2^32-1). Or, exactly 4 billion iterations of the hash function. Even a PC with a 12 year old Pentium 4 CPU that performs at 1 MHashes/Sec (cf. Mining Hardware Comparison) can crack this in 4000 seconds, or in about an hour. Custom ASICs with GHashes/sec performance will crack it in a second.

What is the correction needed to reflect the 'difficulty' parameter in this pseudocode? Does the size of the nonce have to be related to the difficulty ?


texts: Beginner, how to get bitcoins to invest?

texts: What would be the best way to start from scratch in the bitcoin world without investing capital at first?


texts: Why does the Bitcoin client require at least one confirmation before I can spend?

texts: If I accept bitcoin for payment, provide a new address for each payment and make it clear to payers that I consider payment complete only after waiting the ~10 minutes for a confirmation, is there a technical reason why I can't immediately spend the bitcoin without waiting for the confirmation? Is it impossible to spend it because the address has no transactions in the block chain?


texts: Why do we need to chain the blocks (creating blockchain) in a permissioned blockchain?

texts:
The main question is:

What does "chaining block" mean in a permissioned blockchain? OR in any blockchain network in which creating a new block does NOT need consuming resources/energy ? (even in the case of proof-of-stake)

Does "chaining blocks" (creating blockchain) WITHOUT consuming resources (in the case of PoW, this resource is electricity) make sense? where, re-calculating all hash values does NOT have any considerable cost and it takes few seconds.

In other words, Why do we need to chain the blocks (creating blockchain) in a permissioned blockchain network (such as Hyperledger whose consensus mechanism is PBFT)?

What does really mean chaining blocks without consuming resource/energy? where re-calculating all hash values and as a result replacing all blocks can be done EASILY and RAPIDLY.

The thing can make transactions history immutable in Bitcoin, is a PoW with enough difficulty and not only using blockchain data structure. Otherwise, only chaining blocks based on ex. a PBFT consensus (or even based on proof-of-stake) can be interpreted as a fallacy.

What is the role of blockchain (chained blocks) in a permissioned network? where if one is able to change one block, then he could change the whole of chain as well, by re-calculating all previous hash values, since there is NO difficulty to calculate hashes.

Note: I tried to bring up my question in several different forms to be more clear. In the case, you think some additional explanation is needed, please let me know.


texts: How many BTC addresses have balance in them?

texts:
Of all the possible BTC addresses, how many have balance in them?
And what percentage of the total possible addresses is that?


texts:
I will describe my question using an example.

Let's say the network is working on adding block #100 to the blockchain. An attacker recreates block #99 with a combination of transactions that are "legit", meaning that they can be hashed to the same hash that the actual block #99 is using (and there is no double-spend).

Then, he broadcasts the block to the network. How does the network know that this block is fake and rejects it?

I think it has something to do with PoW, but I'm not 100% sure. Can someone explain to me the process of rejection with a detailed explanation?

Thanks in advance for any answers!


texts: Does every nonce really have an equal chance of winning?

texts:
I set out to test the claim: "Every nonce has an equal chance of winning."

Time Evolution

So, I plotted, with gnuplot, the nonce values vs. hashes for all the valid blocks in the blockchain:(Also, in the last plot, you can really visualize the change in the difficulty and even see where the difficulty was decreased.)

Histograms

It makes sense that the nonces found are skewed toward 0 because this is a selection effect: most everyone starts searching for nonces starting at 0, so the lower nonces are found first, even though there may be also higher nonces that could produce a winning block:

Why are the hashes distributed this way, though?:

2-D histogram of hashes and nonces (logarithmic color scale):


texts: cpuminer: Running two nodes -The requested URL returned error: 500 Internal Server Error, json_rpc_call failed, retry after 30 seconds

texts:
I'm trying to mine new blocks using cpuminer. My blockchain network runs on localhost on the testnet network with two nodes. When I'm trying to mine the blocks I'm receiving the following error:
* TCP_NODELAY set
[2020-08-19 10:46:01] Binding thread 6 to cpu 6
[2020-08-19 10:46:01] Binding thread 4 to cpu 4
* Connected to 127.0.0.1 (127.0.0.1) port 18001 (#0)
* Server auth using Basic with user 'liork'
[2020-08-19 10:46:01] Binding thread 2 to cpu 2
> POST / HTTP/1.1
Host: 127.0.0.1:18001
Authorization: Basic bGlvcms6aXJvY2s=
Accept-Encoding: deflate, gzip, br
Content-Type: application/json
User-Agent: cpuminer/2.5.1
X-Mining-Extensions: midstate
Content-Length: 147

* upload completely sent off: 147 out of 147 bytes
[2020-08-19 10:46:01] Binding thread 0 to cpu 0
* Mark bundle as not supporting multiuse
* The requested URL returned error: 500 Internal Server Error
* Closing connection 0
[2020-08-19 10:46:01] HTTP request failed: The requested URL returned error: 500 Internal Server Error
[2020-08-19 10:46:01] json_rpc_call failed, retry after 30 seconds

My nodes configuration:
Node1:
...
# Options only for testnet
[test]
connect=127.0.0.1:17002
rpcport=18001
listen=1
port=17001
rpcuser=myuser
rpcpassword=mypassword
...

Node2:
...
# Options only for testnet
[test]
connect=127.0.0.1:17001
rpcport=18002
listen=1
port=17002
rpcuser=myuser
rpcpassword=mypassword
...

I'm running the cpuminer using the command: ./minerd --url=http://127.0.0.1:18001 --user=myuser --pass=mypassword --coinbase-addr=my_address --protocol-dump


texts: How to setup https ssl letsencrypt for NXT / Ardor public nodes?

texts: I want to run my own public nxt / ardor node, but I also want https (letsencrypt). I have a ubuntu server with apache 2.4 installed already. What are the steps to get this setup?


texts: How to get Bitcoin Cash from Multibit HD wallet?

texts:
Multibit HD still works but is no longer supported so I sent most of my bitcoins to my new ledger nano s hardware wallet.
I now gather there may be bitcoin cash associated with the old multibit wallet that could still be claimed. If so, how can I do that please?


texts: Where do transaction fees go in block #163368

texts: The reward of the Coinbase TX  is only 50 BTC not including transaction fees. So who owned  these fees?


texts:
Block size is still limited to 1MB. As I understood, transaction size is no longer limited. So can I be sure that my transaction with 29000 outputs and reliable fee will be included into block?
Or what is the max transaction size?


texts: How can I prevent Armory from getting stuck at "30 seconds" Building Databases on OSX 10.9?

texts:
I'm running Bitcoin-Qt v0.8.6-beta and Armory 0.90-beta on OSX 10.9. I've been stuck at "30 seconds" for several hours. This has happened twice now. Activity monitor displays no disk activity, but ~90-120% cpu usage. Bitcoin-Qt is fully synced and displays a green checkmark.

Any help would be appreciated, thanks!

EDIT:
The log file contains a bunch of messages similar to this:

  -ERROR - 1394339952: (leveldb_wrapper.cpp:1145) Block height exceeds DupID lookup table
  -ERROR - 1394339952: (leveldb_wrapper.cpp:1145) Block height exceeds DupID lookup table
  -WARN  - 1394339952: (BlockUtils.cpp:4617)    Tx: d5fdcc541e25de1c
  -ERROR - 1394339952: (leveldb_wrapper.cpp:1145) Block height exceeds DupID lookup table
  -ERROR - 1394339952: (leveldb_wrapper.cpp:1145) Block height exceeds DupID lookup table
  -WARN  - 1394339952: (BlockUtils.cpp:4617)    Tx: 982051fd1e4ba744


texts:
I have a doubt on Bitcoin wallet. Suppose I have an online Bitcoin wallet. Now, someone breaks into my computer and steals my Bitcoin wallet. Fortunately I have a
backup of my wallet on another computer. Now, What determines who has the bitcoins now?


texts: How to distinguish addresses currencies apart on php

texts:
I need depending on the address to assign a value of the transaction.
Both at the level of php distinguish btc ltc from ppc?


texts: Ripple: How to monitor multiple accounts reliably and effectively?

texts:
rpc = RippleNetwork(app.config['RIPPLE_SERVER'])
poll = RippleNetwork(app.config['RIPPLE_SERVER'])
last_ledger = Variables.get('ripple_last_ledger')
poll.subscribe(streams=['ledger'])

while True:
    trans = []
    try:
        rst = rpc.account_tx(account=withdraw_wallet, ledger_index_min=last_ledger, limit=1000)
        trans.extend(rst['transactions'])
        while rst.get('marker') is not None:
            rst = rpc.account_tx(account=withdraw_wallet, ledger_index_min=last_ledger, marker=rst['marker'], limit=1000)
            trans.extend(rst['transactions'])

    except RippleException as e:
        if e.resp['error'] == 'lgrIdxsInvalid':
            log.debug('ledger_index_min too new, sleeping for 10s')
            time.sleep(10)
            continue

        raise

    for rec in trans:
        tx = rec['tx']
        log.debug('Got tx %s', tx['hash'])

        if tx['TransactionType'] != 'Payment':
            continue

        if tx['Destination'] != withdraw_wallet:
            continue

        log.info('Queue tx %s', tx['hash'])
        tube.put(str(tx['hash']))

    last_ledger = rst['ledger_index_max'] + 1
    Variables.set('ripple_last_ledger', last_ledger)
    db.session.commit()
    # Wait for next(or several) ledger close here.

Code above is my current implementation, but this method does not scale to thousands of accounts.

Is there any 'best practice'?


texts: Can Bitcoin Core be made to display/enter amounts in USD or other fiat currencies?

texts:
Every time I need to make Bitcoin payments, I have to switch many times between Bitcoin Core and my separate Bitcoin currency converter. For example, to see how much that transaction fee is in USD.
It would be very useful if it could be made to display a fiat currency instead.
Since this requires reliance on a third-party service, I understand why this is not built in.
However, can't I enter in the configuration file something like:
currency_converter_url = 'http://127.0.0.1/btcconverter/'

And then Bitcoin Core could make requests such as:
http://127.0.0.1/btcconverter/?satoshis=123456&to_currency_code=USD

In order for my own script to output how much that many satoshis are in USD currently, so that it can display it to me.
Is this possible? It would be extremely useful.


texts: how can I resolve an unconfirmed deposit to my blockchain.info wallet?

texts:
After 35 hours and still Unconfirmed bitcoin deposit to my blockchain.info wallet after I sweeped the bitcoins I have in my paperwallet which I created on bitaddress.org.

Hello everyone, this is my first time having a problem with unconfirmed bitcoin transactions!  I hope somebody can help me resolve this issue by sharing their
knowledge and experience and point me in the right direction, thank you so much in advance!

About 35 hours ago, I used the blockchain.info wallet to sweep a bitcoin paper wallet private address where some of my bitcoins were stored!
(I created the paper wallet address on bitaddress.org., and I have been storing bitcoins like this and sweeping it with blockchain.info wallet for the
past year and a half without ever any problems regarding delayed transactions.)

Anyway, this time after the wallet was successfully sweeped, and the bitcoins were transferred from my paper wallet to my blockchain.info wallet,
it sits indicating as a pending transaction awaiting confirmation.

If I send some of that funds out by setting a higher priority transaction fee, would that help confirm both transactions?

My paper wallet public key which I sweeped the funds from is:  1EwT9GvF5vvRq4wW1YS1h4cLgJqdEiF4Mg

Please help me check the status, and let me know how I may resolve this unconfirmed transaction asap, thank you so much for your kind assistance!
Dave


texts: How to create a sending address with Bitcoin Core?

texts:
I downloaded Bitcoin Core and I'm just having a look around and I can't for the life of me figure out how to create a sending address.

I'm using a site to buy stuff and to register I need to "Setup your payout addresses" which is "the address where centralised escrow is released to the seller, and where buyer refunds are sent".

So, what do I do?


texts: I'd like to use US dollars to buy bitcoins in Zimbabwe. Does anyone know how I could do this or how to find bitcoin sellers in Zimbabwe?


texts: ripple consensus - mathematical certainty for all unl graphs?

texts:
It has been stated that ripple reaches to consensus with mathematical certainty.
If we analyze the consensus protocol, we can see that a specific validator can have a very narrow view of the state of the rest of the validators. At least 80% of his unl list must have proposed to include the transaction. Each of them received from 70% of their unl list such a proposal etc....

Unless all those nodes represent the 80% of the unl list of any validator, one cannot assume that the initial validator has knowledge there has been a global consensus on the new ledger.

A problematic example is a unl graph whose directed distance is more than 6 and has low connectivity.

Is this correct? if true what are the assumptions ripple makes on the unl graph so that the above happens?

Edit: wouldn't 2 disconnected networks reach to 2 different consensi, and thus have complete luck of knowledge of the second consensus? If we assume a graph and 2 subgraphs that are connected but have a core that is far away from their boundary. A validator that is inside that core, it will assume that consensus has been reached and only the validators at the boundary will know that there is no consensus.  In other words, shouldn't the unl list be build by a uniform random selection of all the trustworthy validators,or there is chance to not be able to detect the absense of consensus?


texts: What is the difference between policy and consensus when it comes to a Bitcoin Core node validating scripts?

texts:
What is the difference between policy and consensus when it comes to a Bitcoin Core node validating transaction scripts? Can you give some examples of checks that are considered policy and checks that are considered consensus?
This question was asked during this Bitcoin Core PR review club session on PR 19698.


texts: What exactly makes altering of data in non-bitcoin blocks hard?

texts: If leading zeros is only bitcoin requirement, then what makes altering of data in blocks hard? Like now its easy to modify a block and generate new hash for every subsequent blocks since generating hash is not as costly compared to bitcoin requirement.


texts: What can be done with a bitcoin besides exchanging it for goods or services?

texts:
Some people have described a bitcoin as a commodity, but every commodity I see on this Wikipedia page seem to have a non-financial purpose, which also gives it a financial value.

What can be done with a "Bitcoin" (if anything) that has a non-financial purpose?


texts:
what is the meaning of this SCRIPTPUBKEY:

OP_DUP OP_HASH160 OP_PUSHBYTES_20 xxxxx....xxxxxxxx OP_EQUALVERIFY OP_CHECKSIG

in particular I searched for some documentation on OP_PUSHBYTES_X which only explains what exactly that instruction does but now why it is used or why it interesting.

Thanks for pointing me to any "more divulgative" resource than the bare code:)


texts: Why I obtain this error trying to compile this wallet?

texts:
I am not yet a Linux guy and I am going crazy trying to install the MJ Coin wallet compiling it on Ubuntu 14.04.

This are the only provided instruction to install it:

  Debian

  First, make sure that the required packages for Qt5 development of
  your distribution are installed, for Debian and Ubuntu these are:

apt-get install qt5-default qt5-qmake qtbase5-dev-tools qttools5-dev-tools \
    build-essential libboost-dev libboost-system-dev \
    libboost-filesystem-dev libboost-program-options-dev libboost-thread-dev \
    libssl-dev libdb++-dev

then execute the following:

qmake
make

So I have installed the dependencies using apt-get and it seems to me that I have no problem.

Then I perform qmake and I obtain the following output:

andrea@andrea-virtual-machine:~/Documenti/wallet/MJcoin$ sudo qmake
Project MESSAGE: Building with UPNP support Removed plural forms as
the target language has less forms. If this sounds wrong, possibly the
target language is not set or recognized. Removed plural forms as the
target language has less forms. If this sounds wrong, possibly the
target language is not set or recognized. Removed plural forms as the
target language has less forms. If this sounds wrong, possibly the
target language is not set or recognized.
andrea@andrea-virtual-machine:~/Documenti/wallet/MJcoin$

Finally I execute the make compile command but I obtain the following error message:

.........................................................................
.........................................................................
.........................................................................
cd /home/andrea/Documenti/wallet/MJcoin; /bin/sh share/genbuild.sh
/home/andrea/Documenti/wallet/MJcoin/build/build.h g++ -c -m64 -pipe
-fstack-protector-all --param ssp-buffer-size=1 -O2 -D_REENTRANT -fdiagnostics-show-option -Wall -Wextra -Wno-ignored-qualifiers -Wformat -Wformat-security -Wno-unused-parameter -Wstack-protector -fPIE -DQT_GUI -DBOOST_THREAD_USE_LIB -DBOOST_SPIRIT_THREADSAFE -DQT_DISABLE_DEPRECATED_BEFORE=0 -DUSE_UPNP=1 -DSTATICLIB -DHAVE_BUILD_INFO -DLINUX -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I/usr/lib/x86_64-linux-gnu/qt5/mkspecs/linux-g++-64 -Isrc -Isrc/json -Isrc/qt -Isrc/leveldb/include -Isrc/leveldb/helpers -I/usr/include/qt5 -I/usr/include/qt5/QtWidgets -I/usr/include/qt5/QtGui -I/usr/include/qt5/QtCore -Ibuild -Ibuild -o build/net.o src/net.cpp src/net.cpp:19:32: fatal error:
miniupnpc/miniwget.h: File o directory non esistente  #include
<miniupnpc/miniwget.h>
                                ^ compilation terminated. make: *** [build/net.o] Errore 1

The enghlish translation of the error output is: File or directory don't exit #include miniupnpc/miniwget.h

What could be the problem? How can I try to fix it?


texts: Is Bitcoin network an Asynchronous network or a synchronous network?

texts: Conventional BFT protocols work on weak timing assumptions, and if a faulty primary does not respond or forward a client's request a view change message is initiated by the backup nodes. Therefore, if an adversary delays the messages beyond timeout period, he can affect the network through a DoS attack.  The blocks in Bitcoin Blockchain are also time-stamped, therefore, I just want to confirm that does delay in reaching of any transaction or Block to maximum nodes affect the validity of that transaction/block after any timeout period?


texts:
My goal is to understand bitcoin.
I do not want to earn money with mining.

I have a server without GPU (intel i5 with 4 cores)

Here is what i've done: I have downloaded, maked and installed bitcoin sourcecode from github. It seems to work because i can interact with bitcoind with bitcoin-cli command.

I want to enable mining, but i do not know how to do. I have read some tutorials but i do not understand if mining is really enabled.

How long does it take on an intel i5 to generate the smallest bitcoin fraction as possible. I just want to see if it works

Thanks


texts: Which online wallet has the least transaction fees?

texts:
I used to use Coinbase.com, but recently the fees are jumped up dramatically, so that for example for a $14 transaction it charged me $2 today. That's to much even by Paypal standards!

So I'm wondering whether it's a general trend that the fees increased so sharply? And nonetheless what other known wallet offers the least transaction fees?


texts: How can I run bitcoin-cli with disabled syncing?

texts:
I have synced about 200.000 blocks and that's enough for my purposes. So I want to use bitcoincli, but when it runs with enabled syncing (by default), my computer works to slow.

How can I disable syncing for some time? Probably I need to set up something in bitcoin.conf, but I don't know what.


texts: Bitcoin core for Mac OS X stuck at the 95% mark for hours

texts:
My Bitcoin Core app (the latest OS X client) is downloading the chain. It has been at the 95% mark for many hours now. It's progressing, but very slowly.

Is this normal?

I would think so, because this is not the first time this happens to me.


texts:
I have an 'omnibus' wallet.dat which holds balances for multiple parties which I would like to disentangle and split. The UTXOs are not blended, each UTXO is owned by a given party in whole and there  has been no key reuse throughout the wallet's life. It is not an HD wallet.
Q) What is the best way to 'fork' this wallet into multiple new wallet files, one per party, such that I can retire/deprecate (obviously not delete) the old wallet, while still propagating the same UTXO states and transaction histories into the new wallets?
This is a question about delicate wallet manipulation without any on-chain activity.
I have tried dumpwallet to obtain the list of keys+addresses, separated the relevant ones manually and then used importwallet on each resultant file into a new wallet.dat for each. This sometimes loses address labels, and seems to adjust the transaction timestamps versus the original file. There is apparently some metadata lost in the transfer, is there a better method for what I'm trying to achieve?


texts: Generated new cryptocoin but how to get balance in my account?

texts:
I have created new Cryptocurrency from litecoin's fork.

And I can connect more than 2 node with successfully.

But How to pull original balance in my wallet?

Let me share screenshot: https://ibb.co/gci8kn

Balance: 0
Unconfirmed: 0
Immature: 120 MIND.

How to transfer amount 120 MIND in original balance?

I did "setgenerate true" from debug window but it increases only Immature amount.

Please let me know about it. It is very important for it.


texts: Is a proof of work consensus mechanism that discourages mining in pools possible?

texts: Most proof of work cryptocurrencies, including Bitcoin, have most of their hashrate controlled by the biggest mining pools which significantly decreases decentralization. Would it be theoretically possible to create a proof of work algorithm that distributes the block reward to miners relative to how many shares they have submitted? Basically make it so that the algorithm itself is a decentralized mining pool.


texts: Start and end parameters in historical price data request are ignored

texts:
I trying to do some testing on historical coinbase data. Because I can only get 300 datapoints per request. Im looping the request and change the start and end paramter to got backwards.

My requests now look like this:
https://api.pro.coinbase.com/products/BTC-EUR/candles?granularity=60&start=2018-11-09T17:11:08Z&end=2018-11-09T18:11:08Z

AFAIK they are ISO 8601 formatted and the time difference between start and end is correct.

However, im getting not 60 points but 350, so the end date is ignored and the start date also changes whenever I reload the link.

Can someone shine some light on how to correctly do the request for 1 hour of data?


texts: So far I've seen Pushpool, PoolServerJ and P2Pool. Which one of this would be easiest to set-up, maintain, effectiveness, and overall security?


texts: I assume they run bitcoind for the network connectivity.  But what about for the work allocation?


texts: Do transactions including CHECKLOCKTIMEVERIFY get mined immediately?

texts:
As I understand it, nLockTime prevents transactions from being included in a block, or even relayed. The problem is, if I pre-sign a transaction, and give it to someone, they have no guarantee that I won't invalidate that transaction by spending its inputs somewhere else before the nLockTime enables the transaction I gave them.

If I create a transaction with CHECKLOCKTIMEVERIFY, that gets mined immediately, right?

What is an example CLTV pair of transactions, including the one that sets the condition, and the one that spends it? It would be helpful to see example sequence numbers, transaction nLockTime, CLTV value, and block numbers for the two transactions.

The following question contains the relevant CLTV code:

Why is OP_CHECKLOCKTIMEVERIFY disabled by maximum sequence number?

Here's the OP_CHECKLOCKTIMEVERIFY BIP: https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki


texts: How to generate the digest from a raw bitcoin transaction for verifying signature of specific input?

texts:
I'm writing a stand alone process that needs to verify that a known UTXO is part of a new transaction with a valid signature.

Inputs [ UTXO, raw transaction, input_number ]

How do to I verify the signature for this specific input?

As I understand, depending on the SIGHASH, I would need to parse the entire transaction and replace/remove some data. However, the length bytes seem to make the entire process extremely complex.

Does a segwit transaction make everything easier? Or are there still bytes that need to be removed depending on SIGHASH?

On a side note. in general, will APIs that return "raw transactions" no longer have the signature data for segwit transactions? or are they all appended to the end?


texts: Where can I find people willing to pay me in bitcoin for services?

texts: For those of us unable or unwilling to spend our native currencies on bitcoin, but willing to work for them. Where are the bitcoin-jobs(or micro-jobs) to be found?


texts:
I was scammed November 2017 by a woman called, Adele Johnson. I wanted to trade on bitcoin, but didn't had the experience to do it myself. She offered her help to trade on behalf of me. I paid R8000 into my Luno account where she requested all my registration details as well my wallet address. She made use of Tradeway Option Platform to trade for me. According to her my money growth to $50 000 and for me to withdraw this money I need to pay $7000. I told her I don't have such money, she got angry and blocked me.
A man, called Artem Vladys told me he can help me to trace this money through interpol. He requested a payment of $300 and he assured me that will be the only payment I had to make; which I made via Luno, I bought him bitcoin worth $300 and sent it to the wallet adress: 154oDjBXc1wSzYncP6YwrU7a9duVGd3J3. He requested another amound of $200, I unfortunately refused to make another payment before I haven't seen what he did to assist me tracing my lost money. He got mad and he blocked me.
Both people said they work for bitcoin.
All the transactions shows in my luno account. Is there any possibility that I can trace this money? Is there not honarable people/organisation who can get my money back?


texts: How can size of a block be significantly small?

texts:
As we all know bitcoin block size should be sth about 1MiB. (Some blocks about 2MB). And this is because miners put all transactions to the block every 10 minutes.

So what happens technically that causes some tiny blocks to be relayed to the network occasionally?! For example: Block #593577

Let me add that its mined at same time with a couple of other blocks:

#593576
#593575

So maybe its gonna become an orphaned one.

But my question is about the reason behind mining & relaying such a tiny block with as small number of transactions as 46?! Is it because of sth like low number of connected peers? or weak network connection? Or what?!


texts:
Is it possible to run Bitcoin mining and transaction distribution without using the internet?

For example, how would Bitcoin continue in the event of a total clampdown by a telco?


texts: I can't find information on who actually issues the bitcoins. I understand that miners generate new bitcoins but what party is responsible for issuance?


texts: When did Bitcoin start to allow more than 2 transaction outputs?

texts:
The original Bitcoin paper specifies that:

Combining and Splitting Value

(...) Normally there will be either a single input from a larger
previous transaction or multiple inputs combining smaller amounts,
and at most two outputs: one for the payment, and one returning the change, if any, back to the sender.

As I understand, there is currently no limit on the number of transaction outputs. Was Bitcoin ever implemented in a way that allowed no more than 2 outputs? If so, when did it change, and were there any opposing arguments in the community/from Satoshi for keeping the maximum number of outputs at 2?


texts:
I think to setup an ASIC Ant Miner in my university apartment.
I am new to Bitcoin mining and since the university network does block any Bitcoin related connections I was thinking to use my smartphone 3G internet for this purpose.
 But now I wonder what bandwidth speed will I need to maintain 24/7 mining process without any bandwidth speed issues.


texts: Is there an alternative to identify a lightning node without their IP or onion address?

texts:
In the country where I live, only dynamic IPs are assigned to most customers unless you are willing to pay a lot more for a business service.
I guess not everyone in the world can get a static IP without paying a lot extra or doing something like running a VPS.
Also, a node operator with a static IP address doesn't have total control of the IP assigned to them.
I learned that lightning uses the IP or onion address of the node to identify it, so if a node changes their IP - I guess - it assumes the node is not online anymore. Which, I understand, is a problem if you open a channel with a node.
So, my question is: is there an alternative method, implemented or not, to identify a lightning node without knowing their IP or onion address?


texts: Destination address/transaction keeps switching

texts:
So, a few weeks ago I sent a BTC transaction out of my atomic wallet with stupidly low fee. Realised my mistake and have been been waiting on it dropping out since. Finally showed back in my wallet so I resent it with a the default fee, quickly as I just wanted it out, but to a different wallet. However, its stuck. Looking at my address sometimes it shows the original transaction unconfirmed refresh a couple of times then it shows the new transaction unconfirmed and repeat. The new wallet I was sending to has recorded a receiving transaction but when you click explore it can't find it. Is this another case of waiting as it looks like the default fee for the new transaction was still rather low, or am I stuck with it flip flopping and continually being rebroadcast?
Sending Wallet address:
1FjDzvp7b5SJYMYAuj38S6jLQ3LMXLHk92


texts: do you need to independently create a genesis block for a new altcoin?

texts:
So if one was to try to create an altcoin that was a fork of the bitcoin code would he/she have to create a genesis block independently first?

static CBlock CreateGenesisBlock(uint32_t nTime, uint32_t nNonce, uint32_t nBits, int32_t nVersion, const CAmount& genesisReward)
{
    const char* pszTimestamp = "anything you want";
    const CScript genesisOutputScript = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
    return CreateGenesisBlock(pszTimestamp, genesisOutputScript, nTime, nNonce, nBits, nVersion, genesisReward);
}

Is changing the variable for pszTimestamp in the above function from chainparams.cpp sufficient?

If that's all that's necessary, then what is the purpose of this "gensis block generation script"*?

*From this question.


texts: How does a miner insert the hash of a merged-mined alt chain's transaction into a Bitcoin transaction?

texts: I've read the how does merged mining work? thread and I'm a bit confused as to how one of the transactions in the bitcoin block "stores" the hash of the Namecoin block. Where is this information stored in the transaction sent to the bitcoin network? As a recipient address? Somewhere else?


texts: Is there a point where bitcoin mining will not be profitable?

texts:
A lot of news accounts are pointing out that bitcoin mining is getting more difficult over time, murch even said recently in chat its getting "exponentially harder". I am not sure if that is the case, but has anyone studied the economics and difficulty/hardness of bitcoin mining over spans of time? it appears clearly & by design to be subject to "diminishing marginal returns".

Is there a forecast when bitcoin mining will reach "break-even" level & be exactly as expensive as the hardware/energy required to mine it?

I am looking for quantitative/scientific analysis where possible. By the way, its a completely separate question of whether this would mean that bitcoin is no longer usable as a currency. (To me that is very likely not the case.)


texts: How to debug a long "0/unconfirmed" status in the bitcoin client?

texts: When someone gets a status of "0/unconfirmed" on a transaction for a long time - what could he be doing wrong? What should he check to solve this?


texts: How can I install Bitcoin Core without having a 350GB harddrive?

texts:
I would like to run Bitcoin Core on my laptop with approx 100 Gb of HDD available.
From the installation instructions I understand that a full node must initially download the full approx. 350 Gb blockchain, but can then be pruned down to 5 Gb and still work fine for most use cases such as fully verifying incoming transactions.
Is there a way for me to install Bitcoin Core, and let it download and verify the entire blockchain but continuously pruning it in order to never require more than, say, 50 Gb of data simultaneously?
I cannot find anything about this in the installation instructions at:
https://bitcoin.org/en/full-node#initial-block-downloadibd
Thankful for your advice!
/bitcoinomnivore


texts:
This paper argues that

  the bitcoin 4-year reward halving system very disturbing. We see
  absolutely no reason and no benefit of any kind to have this sort of
  mechanism built in a crypto currency. On the contrary, we claim that
  this mechanism is unnecessary and harmful. It somewhat discredits
  bitcoin as a stable currency which could be a reliable store of value.
  At the very least it can seriously limit a wider adoption of bitcoin.
  Therefore we propose to change it as soon as possible and propose a
  modified reward formula.

Is the "4-year reward halving system" flawed?


texts: Is there a rationale for the compact representation of the target?

texts:
In Bitcoin, the target is a 256-bit unsigned integer stored using a compact representation similar to a 32-bit floating-point with the following parameters:

1 sign bit (is there any use?)
8-bit exponent with offset binary 3 (why?)
base 256 (by using this base, couldn't the exponent be 5-bit long? By definition, the maximum target is set to 2^224 - 1 = 256^28 - 1)


texts: Is it cheaper to store data across multiple instances of the same contract?

texts:
From what I understand, code is deduplicated on the Ethereum blockchain by storing pointers in new blocks to blocks containing code that is being reused in the new block.

If that's the case:

Is it better to store a new instance of a contract for each set of data (for example, information about a user), or...
better to have just one contract that stores all data in a data structure like an array of objects (for example, storing information about all users in one contract.

To clarify with some incorrect pseudo code, should I store my information like this?

contract Whatever {
  Users = [
   {}, {}, {}, {}
  ]
}

or like this:

// User 1
contract Whatever {}

// User 2
contract Whatever {}

// User 3
contract Whatever {}

// etc.


texts: Need help with encrypted wallet.dat. I can't access it with my expected pass-phrase

texts:
I created an offline wallet in 7/13 via a Ubuntu live CD. I recently imported the encrypted wallet.dat file into the bitcoin-qt wallet on Windows 7. Coins appeared. But, my expected passphrase is incorrect. At first I though I mis-recorded it or mis-typed it at inception. I have contacted a service to try to brute force it. However, I just went to restore and access my offline LTC wallet and same thing. Coins appear but passphrase is wrong. Same mistake twice seems pretty unlikely. Is there any other mistake I could have made that led to this? Please help me brainstorm.

Edit:
I think I figured out I may have done.

1. encrypted wallet
2. copy wallet.dat
3. change passphrase
4. did not make new copy of `wallet.dat`

First encrypted copy would not decrypt with the new passphrase. Unfortunately, at that time I would not have grasped the consequence of resetting the passkey (ie re-encrypting the wallet.dat) and not creating a new backup of wallet.dat.

Edit 2: As a follow up it was a passphrase issue (mistyped twice at encryption). I was able to discover the actual passphrase by using the ruby script from this thread https://bitcointalk.org/index.php?topic=85495.

See my post # 312 for the details if you need help solving this kind of problem. The folks in that thread are very helpful.

Much thanks to all who helped. It was a stressful and frustrating experience - from which I learned a lot. :)


texts: bitcoin historical data (both daily and intraday)

texts:
I am looking for historical daily time series of bitcoin/eur (or bitcoin against USD) and, if they exist, of other major criptocurrencies possibly since inception.

I am looking for intraday historical data for bitcoin as well. The level of granularity I am looking for is not necessarily tick by tick, price quotes every 5-10 mins would be enough.

Are these two types of historical data available for cryptocurrencies? As I can understand, there should be something in quandl but only at daily level.


texts:
From what I understood, the economic intrinsic value of Bitcoin as a currency is based on the "CPU-work" required to produce them. That is what makes Bitcoin rare enough to qualify as a currency. Is that it?

Now the thing is CPU-work doesn't come free of social costs. Doesn't it have some incidence on things like:
- market prices of fuels (we all end up paying our electricity higher as a consequence of bitcoin, i.e. we bare the burden)
- climate change (future generations will have to pay more to survive in a less stable climate)
- no legal-compliance checks (i.e. bitcoin activity like all business takes advantage of the security of the State but doesn't fulfill the function of checking legal compliance of transactions as the banking system does - or should I say: is legally required to do)


texts: Do multi-signature transactions make a 'bitcoin kickstarter' possible? And what state are the bitcoins in, in the meantime?

texts:
This isn't a question about kickstarter really, just a way for me to phrase my question about the crypto in terms that I can understand.

My understanding, based on this article.. Stop Saying Bitcoin Transactions Aren’t Reversible is that multi-signature transactions would make something like a bitcoin KickStarter particularly easy.

That is the kickstarter-like bitcoin service would act as a third party to many contracts transferring btc to the second party?

Maybe this has already been done? Hmm @coinstarter.. Yay! Great to see but doesn't really answer my question about how the crypto works.

To make things easier I'll call the people that pledge to the campaign the 'first parties' and the recipients of the funds the 'second party'. Could multi-party signatures to ensure the second party only receives btc after the projects are funded? and at the same time be sure that the third party (eg coinstarter) technically can't abscond with the funds.

Also - and this is my real question - in such a case what state are the bitcoins in prior to the project being funded. That is, are they marked in the blockchain and thus impossible for first parties to 'double spend' btc they have pledged to a campaign or are they actually not in escrow so if a first party spends them on something else in the meantime (after pledging, before the project is funded) the transaction just fails?

Thanks so much in advance, hope this question makes sense, crypto wise.


texts: Is there a way to set the aggression for the OS X Diablo Minor?

texts:
I run the OS X Diablo Minor on my new Macbook.  It seems to work well enough and it earns me a few bit-cents each day.

The only problem is that I have to cut it off whenever I'm working on the Mac, because it hogs the GPU.  Is there a parameter or some config file within the .app bundle that I can modify that will reduce the aggression level so I can use my Mac and mine with unused GPU cycles?


texts: If SegWit only increases the capacity to only 2-4x only. Wouldn't we have the same issue in a few years again?

texts: If I understand correctly. SegWit is one of the solutions to the full 1MB block problem that doesn't require a hard fork. But I've read this only increases the 1MB to maybe about 2-4x only. If that is the case, wouldn't we have the same problem down the line when transactions reach that level again?


texts:
bitcoin-qt creates files under ~/.bitcoin/ in my file system. i know that the ~/.bitcoin/blocks/blk*dat files contain the blockchain, but what do the following other files contain:

~/.bitcoin/blocks/rev*dat
~/.bitcoin/chainstate/*sst
~/.bitcoin/blocks/index/*sst

i know sst stands for "sorted string table" and i gather these files belong to a leveldb database, but i'd like to know in more detail what is in each of them.


texts:
I did some reading on the Steem currency, and as i understand it there is no mining of Steem. New coins are created automatically and distributed to the social media contributors..

What i don't understand is who's maintaining the public ledger (the blockchain)? In Bitcoin, miners get new bitcoins as a reward for mining, and maintaining the public ledger by verifying transactions. So if there are no miners in Steem, who is varifying the transactions on the ledger?


texts: I need to import a private key - what is the entire process? [Electrum]

texts: I need to import a private key like in this question for a p2wpkh-p2sh address. What is the entire process?


texts: Is there a system that support job contracts?

texts:
I am wondering if there is a system that support bitcoin contracts like:

If I made a deposit to a wallet - this wallet takes 10% of the BTC and transfer it automatically to another wallet.


texts: Difficulty in verifying bitcoin-core signing keys

texts:
How can I verify bitcoin0.19 signature bwith gpg?
I read I should use gpg --recv-keys signingkey, but I don't understand where is the file signiggkey. I tried to download Bitcoin Core Release Signing Keys v0.11.0+ but what I got is a .asc file, which I don't know how to use


texts: It seems that one can mine bitcoin to obtain more bitcoins, whereas coins like reddcoin allow staking to have more reddcoins. What is the difference between these two processes ?


texts:
Is there any implementation of this Colored Coins Protocol in Python?

I have found colored coins implementations in Python but, as far I as understand, they implement different protocol specifications (for instance Chromaway's ngcccbase or Open Assets).

Thanks!


texts: My friend lost his PRIVATE Keys. Any way we can still retrieve the BTC Wallet? No other info can be provided only BTC Address.


texts: How to run Bitcoin Core as onion service on Windows, Ubuntu and Android?

texts: Have you tried running Bitcoin Core listening on Tor on different platforms? What are your experiences, issues that you faced, hacks, workarounds etc.?


texts: how can I run multi wallet on one computer to share same blockdata

texts: you know ,you need a 32GB size for one bitcoin client,is it possible to run several bitcoin programs sharing same data source using -datadir or something else? I have found that somebody had put it  about a year ago and got an big NO; Since 1 year has passed ,is it still NO?


texts: How important is the fee for speed of confirmation?

texts:
I am developing a Bitcoin application, so I am sending a lot of "toy" transactions for testing, with 0 fees.

But it seems that those take forever to get confirmed. (Right now I am waiting 45 minutes for one transaction to get confirmed. Previously it was about 30 minutes.)

Is my suspicion right, or am I doing something wrong? How important is the fee for miners? Do they preferentiate?

Or am I doing something wrong (not broadcasting to enough nodes, maybe?)?

And do nodes, that aren't miners (with official client I presume), preferentiate to send around transactions with fees?

(edit: note that the question was written in 2012, when the blocks were still empty.)


texts:
I am working through Master Bitcoin. I got the bitcoin client up and running. I am now trying to access the client from python. In the example, there is a line that says from bitcoin.rpc import Rawproxy.

I get the error message no module named rpc. When I run pip freeze, I have python-bitcoinrpc==1.0 listed. Why can't this module be found?


texts: Proof-of-Stake: How to ensure immutability of the blockchain?

texts:
In Proof-of-Work, a miner tries to solve PoW puzzle based on the hash of previous block, such that in case of changing block B_i, all blocks after that (blocks B_i+1, B_i+2, ...) are no longer valid since puzzle of every block has been solved based on the hash of previous block.

Now, in a scheme without mining consensus such as Proof-of-Stake, does a validator have to use/insert the hash of previous block, B_i, in the new block, B_i+1 ?

If yes, How ?

And if No, how are blocks chained such that in case of changing a block, B_i, all blocks after this modified block will become invalid? We would need to chain blocks to each other to ensure immutability of the data stored in the blockchain.


texts: How much should I charge a client if they pay me in bitcoins?

texts:
The price of bitcoins fluctuates rapidly against other currencies. If I were to go to a restaurant and pay for a meal in bitcoins the price at the start of the meal would almost certainly be different by the end of the meal. In fact I have heard of this behavior happening in countries undergoing hyperinflation.

So how should I charge a client for a service when price of bitcoins change?  How should you pay employees an hourly rate in bitcoins when the price changes for each hour?


texts: What do the "Fetch Wallet" options when opening a Ripple wallet mean?

texts:
When I open a Ripple account, I can choose to fetch my wallet from

Payward, Local Browser
Payward
Local Browser

What does this mean? Can someone elaborate on the differences, and when is each option appropriate?


texts: About confidential transactions blinding key

texts:
I have a small question about confidential transactions. In it, a secret random blinding key is used to generate a Pedersen commitment. Is that mean that the recipient's blinding key is determined by the sender, and sender deliver the blinding key to the recipient in private channel?

My question may be stupid. It would be great if anyone could shed some light on this.


texts: How to get list of all transactions in bitcoinj wallet?

texts:
I configured bitcoinj library so I can connect to network, replay blockchain, create addresses, receive and send bitcoins. I using FullPrunedDatabase as block store.

I'm still missing how to find all transaction in this wallet. I'm also interested how to compute confirmed and unconfirmed balance on single address. I know this one was asked here before,How to get balance from a specific address in bitcoinj?, but I cannot figure out how to use CoinSelector


texts: It sounds like a headline from The Onion, but is it really true?  I can't find anywhere I can buy the eBook Mastering Bitcoin using bitcoin, only PayPal or Credit Card.


texts: Displaying price in ETH based on USD exchange rate

texts: How do i get the ETH rate in USD, and stored in a variable in php?


texts: Genesis block coinbase transaction without confirmations

texts:
Why the coinbase transaction, comming from the genesis block, don't have confirmations?

All the others coinbase transactions have confirmations, but not in the Genesis block.


texts: Can 2 blocks have the same previous hash?

texts:
Can two blocks have the same Previous hash after being created.

2 blocks totally different from each other but with the same previous hash


texts: What advantage do Mt.Gox or Kraken have over Coinbase?

texts:
I just verified at Mt. Gox and am pending verification at Kraken.  However, I quickly realized that there were hurdles that I needed to jump through in order to get my USD into BTC.  Coinbase was a much easier alternative.

What advantage do Mt. Gox or Kraken have over Coinbase?  I realize it's quite easy to move BTC into both Mt. Gox and Kraken hosted wallets.

Is it purely anonymity, pricing, or something that I'm missing, like trade execution features?


texts:
Does bitcoin have enough resolution to replace all other currency?
Bitcoin is intended to be used globally, and ideally it would be used in place of government issued currencies.  For the purposes of this question lets assume that all transactions in the world will take place in bitcoins and that all governments and people have accepted it as legal tender.
There are 100 million satoshis per bitcoin and 21 million bitcoin.  That means the total wealth of all bitcoins can be divided into 2,100,000,000,000,000 units.
If there are 7 billion people in the world then there are only 300,000 satoshis per person.
If each satoshi ultimately became equivalent to say a penny, that means that we can only have $3000 per person, which seems sort of limiting.  If we make each satoshi something larger than a penny (like $3.00), then each individual could have up to $900,000 in wealth.  But then there would be granularity problems (like having to charge $3.00 minimum for any item no matter how small).
The granularity problem gets even worse since prices for mass produced items (like small electronics components) are often specified in units as small as 1/100 of a penny.
Clearly there is a resolution problem that will only get worse over time.  To estimate the required resolution we can consider the following.

need to account for very small prices (as small as 1/100 of a penny), so 10,000 units per dollar
need to account for reasonable wealth (say $1,000,000 per person).  Not that I expect all people to have that much, but wealth is not evenly distributed, and we wouldn't want to be even close to hitting the cap.
need to account for population growth (say up to 20 billion)
need to account for lost coins (say at least half are lost over time).

$1,000,000 per person * 10,000 units per dollar * 20 billion people * 2 = 4E20 units needed.  This would require at least 69 bits.
4E20 / 2.1E15 = 190,476.
So it looks like the resolution of bitcoins smallest unit will ultimately need to be at least 200K smaller.


texts: Would it be possible to create a mining pool service that specifically processed only certain transactions?

texts:
I've seen that it's possible to encode custom data in the block chain.

I'm wondering if it's possible for someone to start a mining pool consisting of client that use some metadata in either wallets or their transactions to process only some transactions, possibly for zero fees, that offers a confirmation time service level.

If so how would one determine the amount of processing power required to honour a certain service level?

Would this service undermine some principal technical mechanisms of the bitcoin network?


texts: I'm currently using a program that analyses the block files. It splits all the stuff into multiple .csv files. Is there any method I can do to get the addresses & amount sent/received from tx_in and tx_out?


texts: Got bitcoin on generated address, now my wallet doesn't have the address anymore

texts: I downloaded bitcoin.com wallet and immediately sent myself an email of my BTC address. Right after that I purchased some bitcoin through simplex. So the transactions (I made two, on the same address) went through, i can also see it on blockchain.info. The thing is, that I can't see it in my wallet. Also, the address I sent myself is also not visible in the wallet. I still have the email tho. I went back and forth with bitcoin support (one guy named Steven), i cleared my chache, generated all the new addresses, scanned for funds, I tryed everything he said. He also said that  the error message should not be showing, also stopped believing me about my issue. Ok, so here's the thing I want to know. How can I try to access my bitcoin just through the BTC address? Or at least, can I find out to wich wallet this address is linked to? Because if it is not linked to my wallet, which wallet is it linked then? Can a bitcoin address not be linked to a wallet?  If so, can anyone retrieve the money then? I will be very thankful for any response that could be helpful. Thank you in advance


texts: Is there a java library which could extract the first seen date and the last seen date of an address over a bitcoin network?

texts: Apparently the bitcoinj does not provide such feature.


texts:
Can someone tell me how to get a confirmation please or cancel this;

e8c5489abcb60ecdb925ac880ec1e238c9a65ca4c5480065a6ca268bf00ea7ba-000


texts: Reuse of addresses by a service ("get new address" returning *funded* addresses)

texts:
Recently, a marketplace was said to have been reusing deposit addresses, such that clicking the "get new address" button would immediately give the user a different address, however, the "new address" was sometimes already funded.

Needless to say, this is terrible OPSEC, but I'm wondering how such an issue could arise. Is it a faulty implementation of BIP32? This seems more likely than reusing keypool addresses for bitcoind, but I'm curious how this issue could arise.


texts: I am playing around with testnet and bitcoin rpc. I have send a test transaction of 1 bitcoin as can be seen  here however in my wallet it still shows that the account has 5.2 bitcoin which is what it had before I sent the transaction. I have waited for 80 confirmations and still not change address has shown up and the bitcoins still seem to be in my wallet even though the blockchain clearly shows them as being sent. Can anyone explain what is going on I have never had this behavior when using any other wallet not with testnet which is why I am so confused by this.


texts: Extremely new to Bitcoin but I'm looking to spend some of my balance on Amazon gift cards but I can't figure out why I can't import an electrum wallet backup into bitpay using file or phrase.  Tells me the file can't be decrypted or that the phrase is invalid.  Is this possible or is there a way around it?  TIA


texts: Could you provide an example of a SegWit transaction?

texts: I'm looking for a transaction ID of a non-coinbase SegWit transaction on the Bitcoin network. Could you show me one? Google doesn't seem to do the trick.


texts: Since blockchain is public.. can someone tell how

texts: Since blockchain is public.. can it be found how many bitcoin you own by having your bitcoin public address?


texts:
Can I install and use different wallet apps on one mobile device?

The intention is to have:

a hodl wallet and a daily use wallet
And to compare GUI for preferred UE

Will the apps interfere with each other in any way?


texts:
bitcoin daemon always use 99.99% IO, without using the Internet <1mbit
this is normal?
bitcoin-0.16.0
bitcoin-0.16.2
iotop:
 99.99 % bitcoind -daemon [bitcoin-schedu

Debian 8 x64


texts:
Where could I discuss Bitcoin price speculation, and calculating fair spot and future price.

In general for stackexchange sites, the factors for here and now would be "too localized" I think.

So I will try to broaden it. Bitcoin price - being a deflationary currency with a known max number of coins that haven't been mined or minted yet - seems to be functioning like futures converging to a spot price.

The variable factors being perceived difficulty in mining versus advances in hardware to allow mining, if you look at the difficulty charts and their correlation to price, so far.

I think with just these two factors it will be possible to calculate theoretical prices, independent of the buy/sell bidder's market.

Does anyone have any resources on this, or perhaps a better place to discuss this


texts:
I am trying to get current fee for per transaction. So running command

bitcoin-cli estimatesmartfee 6

i am getting response lookl ike this

{
  "errors": [
    "Insufficient data or no feerate found"
  ],
  "blocks": 1
}

How ca I get real fee?
Thanks!


texts: Is there a possibility that the whole blockchain system will be DOWN?

texts: I want to know if there is a possibility that all of our hard-earned bitcoins will turn to dust if the Blockchain system will get shut down or stop. Is this possible? I really have a big question mark in my mind since Bitcoin is a digital thing.


texts:
Did anyone implement the algorithm from this paper Shared Send Untangling in Bitcoin

I would be interested in seeing it in action.


texts: What is the blockchain? I keep hearing about other "blockchain technologies", does this mean other cryptocurrencies or what?


texts: Distinguishing Lightning channels on-chain

texts: Is there a way to tell (probabilistically, maybe) by looking at an on-chain transaction that it is related to Lightning (is [likely to be] a channel opening or closure)?


texts: How does a mining pool coordinate with different Javascript clients?

texts:
I've been reading a little about those web sites taht surreptitiously had Javascript running on the page that is mining cryptocurrency.  How do those pieces of JS work code generally?  Specifically

Do all pieces of Javascript code report back to a central server which maintains a mining pool?
Does each piece of code get a separate piece of work to do (and get assigned a different worker ID) so the malicious web site can mine faster?


texts: Who wins the race for multiple valid blocks mined at the same time?

texts:
From my understanding, a SHA256 hash is generated by a miner and if the hash is less than a specific value, it is passed to its peers.  That said, It's possible for multiple hashes to be created at very close to the same time.  If this happens, how is the "winner" determined?  I see this has happened a lot (multiple orphaned blocks).

What can be done by the miner to see that their block wins the race, either honestly or through an attack?  The protocol stipulates that the block shall be recognized by which ever was received first.  Is it advantageous to set up peering with other miners?


texts:
I know that SHA256d is strong enough and it's not likely that will be broken soon but let's say someone knows how to find pre-image. The adversary chooses random hash starting with n zeroes (less than target) and finds pre-image (valid block header), let's say 100 times faster (I know it is possible only in theory) than he would need to do this by mining in classic way. What are the benefits that he gets? I think that he can mine faster, so it is easier for him to acquire over 50% of the network hashrate. He can also modify last n existing blocks to remove his transactions (double spending) and create longer blockchain that will be accepted widely in the network. Am I right?

Second but related question. Let's assume we use 8 bit hash function. Is it easier to find pre-image for hash that has to start with 4 zeroes than excatly the same hash? I mean, is finding pre-image for hash 0000xxxx easier than for example 01010101? In the first example there are exactly 16 hashes that can be accepted.


texts: who is the "owner" of a newly mined BTC before its first transaction?

texts:
When a miner adds a new block to the bitcoin blockchain, effectively 900 new coins come into existence as I understand it.  the miner gets 6 of them as payment, but who 'gets paid" for the other 894?
What I mean by that is if I want to then purchase one of these new BTCs, with whom am I exchanging funds for my BTC as they are not yet "owned" by a single person - who is the "owner" until that first transaction occurs?


texts: What is the largest number of blocks that have ever occurred in 1 hour?

texts:
I have see questions about the longest delay between blocks and am aware of some blocks that occur in short succession. However I rarely see many blocks occurring very close to each other (which I suppose is normal since the average time between blocks is 10 minutes)

What is the highest number of blocks that have ever occurred in 1 hour?

How can I search the blockchain to answer this question for myself?


texts: How to debug bitcoin core in "real time"

texts:
I am new to bitcoin core and C++

I downloaded already the project from: https://github.com/bitcoin/bitcoin
and run "makefile" command.
Now I can make all transaction against the blockchain.

I want to have the option to run "getnewaddress" in the command line
and it will stop in a break point in the source code.
but i cann't run the commands "bitcoind" and "getnewaddress", without first building the project.

How can I debug this project?


texts: Is it possible to increase the prune size and get bitcoind to pull previous blocks?

texts:
for example, currently its:
  "size_on_disk": 32084546902,
  "pruned": true,
  "pruneheight": 650668,
  "automatic_pruning": true,
  "prune_target_size": 67108864000,

Is there a way to decrease the pruneheight? I need the prune height to be 630000.
I increased prune=64000 from prune=32000 but from what I can tell it will just store more blocks going forward?


texts:
Suppose I want to write a membership payment app. In this program, I want to give an address and members should send their membership fee to this address:

How can members prove that they paid the fee ?
What do I have to get from members to prove it?
how app should check and verify the owner of transaction ?

I know there is software for this, but I want to know how this system works.


texts: Why does GBTC frequently not track Bitcoin's price?

texts:
As far as I know, the Grayscale Bitcoin Investment Trust (symbol GBTC) is currently the closest thing on the market to a Bitcoin ETF.

According to their web page, the investment objective of the trust is that:

  Shares track the bitcoin market price, less fees and expenses

I have looked at the GBTC share price and compared it to Bitcoin's price on several occasions over the past couple months.  Frequently I'll see GBTC make a huge move (sometimes over 20% in one day) while Bitcoin makes a small move (say less than 5%), or vice versa.

Why is there frequently a discrepancy in the price movement between Bitcoin and GBTC, if GBTC is supposed to track Bitcoin?  There should be no discrepancy at all (and for just about every ETF I've ever seen, there isn't).  But on most days with GBTC, there is a discrepancy (sometimes huge).

Grayscale never responded to my query about this.


texts: bitcoin-cli "Could not connect to the server"

texts:
Brand new Raspberry Pi mainnet node following this walkthrough:

https://medium.com/@meeDamian/bitcoin-full-node-on-rbp3-revised-88bb7c8ef1d1

When I run this command:

bitcoin-cli -rpcuser=username -rpcpassword=password -rpcport=8332 getblockchaininfo

I receive the error:

error: Could not connect to the server 127.0.0.1:8332

When I tail debug.log, the node appears to be fully sync'd and picking up new blocks

My bitcoin.conf file is:

#is required for Fail2Ban
logips=1

#magic RBP optimizations
maxconnections=40
maxuploadtarget=5000

upnp=1

server=1
rpcuser='username'
rpcpassword='password'
rpcport='8332'

walletrbf=1

My apologies if my formatting is bad here, couldn't figure out how to get the .conf to paste as a block of text. Thank you for any ideas on what I'm doing wrong!


texts: Worth investing in to a cloud mining companies?

texts:
Worth investing in to companies like hashflare.io or genesis-mining.com?

Hashflare:

During black friday there's discount - 1TH/s for 100$. Maintenance fee for 1 TH/s is 0.4$ == 0.0005 BTC.

1 TH/s gives 85-90000 satoshi - 50000 satoshi MEF = 35000 satoshi profit (0.257809$) * 30 = 7.71$ per month, 7.71*13 ~ 100$. So, ROI is 13 months...

But profit for 1 TH/s would vary during a year. So 90000 satoshi per 1 TH/s might be even lower, right?


texts: How to calculate the new sequence number N for the new final field Fp curve?

texts:
Are there simplified algorithms or online services or Python scripts where can calculate a new ordinal N for a new finite field Fp in an elliptic curve?
y^2 = x^3 + 7

I know that SageMath exists and in this program can make a calculation using the EllipticCurve () function, but I'm more interested in Python.


texts: Should boost be installed in /usr/ or /usr/local/ for bitcoin-core?

texts: When installing bitcoin-core, libbitcoin or libbitcoin-explorer the build requires the C++ boost library. Is there any reason why I should prefer to install boost in the /usr/ hierarchy rather than /usr/local. Or should I not attempt to link all my C++ projects to the same boost build anyway, and link to a seperate boost build (of a possibly different versions installed in different locations) for each project?


texts: Is bitcoin-qt using bitcoind? or bitcoind is already built in the bitcoin-qt wallet?

texts:
When using bitcoin-qt wallet, all commands are executed externally with bitcoind?

I am asking because I saw an altcoin wallet-QT (DMD) which comes as a single file without any daemon file, does it mean the daemon is already built in the qt wallet?


texts: What happens if a transfer is made to a unused address from the keypool?

texts:
The bitcoin-qt client generates 100 addresses from the start. But they are not shown in the "receive"-list (only one).

If I export such address with pywallet and send something to it. Will it be recognized?


texts:
Which library I must use for JSON? Where is RPC call example ?
How to use RPC of bitcoind or bitcoin-cli? or better Electrum API to get all new (maybe pending) transactions which appears in Bitcoin net?


texts: Does blockchain.info provide wallets and API service for testnet? This information is quite hard to find from their site.


texts: Multisig addresses with keys from different wallets

texts:
I am learning how to handle multisig. First I created a 2-3 multisig address with all keys from my test wallet (bitcoind on server) and sent money to the new multisig address from another wallet. The transaction shows in the test wallet and I can use the unspent output.

Then I created a 2-2 address with one key from the test wallet and one key from another wallet, and sent money to the new address from another wallet.
The transaction shows on blockchain.info:

https://blockchain.info/tx/910298ae8133cc142009539298b6e2127b2c49960facd3b21470e130d07a1701

but it doesn't show in the test wallet, and the new multisig address has zero balance.

Reading this previous Q/A:

Multisig doesn't work unless all keys were generated from the current wallet?

I see that in July 2014 Bitcoin Core only showed transactions to multisig addresses with all keys in its wallet.

Questions:

1) Is that still the case?

2) If so, can I still use the unspent output and how?


texts: Following extended key derivation scheme in BIP49 is there a publicly available test vector repository for mainnet? The test vectors in https://github.com/bitcoin/bips/blob/master/bip-0049.mediawiki#test-vectors are for testnet only.


texts: My client stopped synchronizing, how can I access my wallet?

texts: My wallet has been stuck synchronizing for 21 days, my transfer is in the block chain but I can't get it to sync with my wallet. I've closed firewalls, uninstalled and reinstalled QT with back up and cannot get the wallet to get current, it is frozen and I can't get my 20 BTC. I'm fairly new and am unable to copy and paste blockchain or whatever. I still have the original Bitcoin address the bitcoins were transfered to from my mtgox account.


texts: I mistakenly deposit my BTC to my BCC address. How can i get it back?

texts:
I intended to withdraw BTC from my Yobit.net account, and send it to my BTC address of HitBTC.com account.
But, unfortunately, by my critical mistake, I sent it to my BCC address of HitBTC.com account. This transaction already went through 6 confirms, and the message in Yobit.net indicates that transaction was completed, but there is no deposit in my BTC as well as BCC account in HitBTC.com
Because it's an address of HitBTC.com, I don't have a private key for that BCC address.
I sent e-mails to Yobit.net, and HitBTC.com, but haven't received any response yet. Is there anyone who know I can get my BTC back? Please help me.