texts: Trying to identify implementations for creating BIP 38 encrypted private keys for alternative coins to spark collaborative open source discussions to standardize BIP 38 to support altcoins. Please share any BIP 38 implementation URLs you are aware of that support one or more altcoins for investigative purposes.


texts:
I am running Mac OS X 10.7 on a MBP and OS X 10.8 on a Mac Mini.  The Mini has a Intel HD Graphics 4000 GPU and the MBP has a 3000.

I know that I cannot mine with the MBP as the GPU does not support OpenCL.  The Mac Mini should be able to as the Intel HD 4000 supports OpenCL 1.2.

However when I run:

bfgminer -n
 [2013-12-04 15:35:22] 0 GPU devices max detected

My GPU is not detected.  I have the latest XCode installed as the well as command line tools and compiled bfgminer with the latest install of brew.

I just want to play around with mining and am not interested in buying an ASIC set up.

How can I get my GPU to be detected by bfgminer or cgminer?

Update:

When I run 'bfgminer --verbose' I get the following error:

  [2013-12-04 17:30:57] JSON-RPC call failed: {    "code": -1,
  "message": "Unsupported method 'getblocktemplate'" }


texts:
I'm studying the Bitcoin system and I'm wondering if there's a way to anonymously buy Bitcoin.
Is it possible to charge a wallet (e.g. with a credit card, PayPal account, by person, by snail mail, etc.), without being traceable?
Let's suppose I don't trust any website/person...


texts: When does a node mark a transaction as confirmed or unconfirmed?

texts:
As new transactions are broadcasted, the nodes keep them in a pool of unconfirmed transactions.

One node will add it to a block as soon as it finds a proof of work. At the same time many other nodes are working on the same transactions. When a new block is broadcasted to the network, it should either be marked as confirmed or removed from the pool.

I have a few questions about this process:

1- how the other nodes know the new block is already created so they should stop working on it? (or they don't?)

2- when a new block of transactions are added to the blockchain how the other nodes know they should not consider that transactions in their next attempt? They read the node and mark the transaction as confirmed of remove them? Is there any other kind of message they exchange?

3- if 2 new blocks are added to the blockchain in different branches. the first branch as active because that block came first. a new block arrives and the second branch is discarded. what happens to the transactions in the discarded branch? they are already in the other two blocks of the blockchain for sure? what do the nodes do with them?

thanks!


texts: Can a trade offer be the last leg of a Ripple transaction path? If so, do transit fees apply?

texts:
I think I understand, for the most part, how rippled finds transaction paths, and how gateways can charge transit fees; but some of the edge cases have me wondering...

Let's say my wallet has XYZ from xyzGateway, and I've offered to sell 1000 XYZ for 100 USD from usdGateway.  For simplicity, let's say that's the only offer on the books trading XYZ for USD.

Next, my friend Alice has over 100 USD:usdGateway in her wallet.  And to settle a debt between us, she sends me 1000 XYZ.

There's a path that might work.  The first leg of the path is 100 USD:usdGateway from Alice to me.  The next leg is my own offer to trade 1000 XYZ:xyzGateway for 100 USD:usdGateway.  I would make that trade with myself, so that afterwards my wallet contains 1000 XYZ and 100 USD.

Will ripple find the path described above?  Let's call it path #1.

There's another path that might work.  The first leg is Alice takes my offer, I get her USD and she gets my XYZ.  The next leg of the path sends the XYZ back to my wallet.

Will ripple find this path #2?  Specifically, will it be found even if Alice does not trust XYZ:xyzGateway?  Does Alice's action of sending XYZ to me imply her trust of that currency?

I believe the two paths are equal in their net effect: 100 USD subtracted from Alice's wallet, and 100 USD added to my wallet.  And I still have 1000 XYZ in my wallet. And my offer to sell XYZ for USD is removed from the ledger.

However, transit fees could make those two paths not equivalent.  Let's say that usdGateway charges 1% in transit fees.  And likewise xyzGatway charges 1%.  Path #1 described above would incure 1% fee when Alice sends USD to me (she'd have to send 101 instead of 100).  It's unclear to me, would the trade leg (trade with myself) would incur still more transit fees from either gateway?

And regarding path #2, there would be a 1% fee to usdGateway when Alice trades for XYZ, and a 1% fee from me to xyzGateway, and finally one more 1% fee for the leg sending XYZ from Alice to me?  Am I correct that this path pays single transit fees to usdGatway and double fees to xyzGateway.

Thanks in advance for help with this. Apologies for cramming multiple questions into one post.  I several questions just to understand what Ripple would do when Alice attempts to send the XYZ.


texts: Does BIP148 (UASF) offer any replay attack protection?

texts:
Is there any protection against replay attacks in BIP148?

Despite the popular name (UASF), it's effectively a hard fork (in the sense users with old nodes will be on a different chain), is there any protection against taking the transaction from the longer chain and putting it on "UASFCoin" chain, or vice versa?

Something like Ethereum with EIP155 / chain ID.


texts: Is there anything called anonymous or private bitcoins?

texts:
Are there different types of bitcoins? Is there anything called private or anonymous bitcoin which can not be traced?

This question may sound stupid but I am facing this question right now. I have a client who wants to pay in bitcoins. However the kind of bitcoins he is talking about I have never heard of.

For verification he opened a separate wallet for me from a website called www.fifthelement.io (I never heard of it). Then he transferred a bitcoin and 0.001 in that wallet. Then I transferred that bitcoin back to his wallet for testing. However the confusing part is that I checked these wallets

[![enter image description here][1]][1]

on blockchain.info, it does show the wallets but doesn't show any transaction history which I assume means no record on the ledger.

I am posting the image of that wallet. I know very little about bitcoins so help in this matter will be highly appreciated.


texts:
How can I know which testnet am I on?

I just ran bitcoind -testnet, and I would assume it would connect to the most recent one, but is there a way to know it?


texts: Namecoin: is there any rationale behind the (apparently foolish) choice of having the domains cost an irrelevant price?

texts:
When I first heard of namecoin an address costed 50 NMC, now they are priced 0.01 NMC.

This means they are as much as free, and the only thing preventing someone from just brute-force registering tons of them is... that it is pointless to do so, because due to this problem itself, namecoin is essentially a worthless project.

Using a bitcoin-like currency to handle DNS was a nice idea at first, and I have no clue about what could have caused them to mishandle the design so much.

Question is, did they state somewhere the reasons behind this apparently foolish decision to set the registration prices to "basically free" after a little while? Didn't anyone point out how stupid that idea was?


texts: What are the differences between the various MTPs in Bitcoin?

texts:
I think there are 3 different MTPs (median time past) in Bitcoin (though this may be incorrect). David Harding said on IRC that there was a MTP in Bitcoin v0.1 (Satoshi's first release). There is also MTP as used in BIP 9 and then there is MTP as defined in BIP 113.
If indeed there are 3 different MTPs in Bitcoin, why? What was the motivation?


texts: Is there any way to get the block number of generation from coinbase?

texts: I was looking on http://blockexplorer.com/ and saw a coinbase of 304602210088c72f5fae851934be23ea7f563ce0424397939480e52c27225efbd8c0c1fccc022100e882cc00e76ae150aefe76fa89a262198d4f1d67f95d2cc3a60ce189017c199901 and wondered what block it was a reward from. I didn't know if the coinbase has anything to do with what block it was generated in.


texts: check if transaction is spendable in bitcoinj

texts: Is there some kind of check if incoming transaction is normally spendable by the bitcoinj wallet? I mean to check if there is no time lock and it's not multisig or whatever can prevent receiver from spending such transaction ? I'm interested in solution within bitcoinj library, online tool might be usefull too.


texts:
It says here https://github.com/bitcoin/bitcoin/blob/master/src/wallet/wallet.cpp#L2458
that to choose coins for a transactions we need to solve subset sum.
But subset sum is when you're not allowed to go over a certain amount;
whereas in bitcoin you can go over the amount and give change.
So why is this necessary?


texts: Where can I find a list of business which accept Bitcoin?

texts: I'm looking for business which accept Bitcoin, both online and in my community. Where can I find a list of these? Are there any community-maintained places which enumerate businesses which accept Bitcoin?


texts: How in laymans terms do I restore a .dat BTC backed up wallet file on my mac please?

texts:
the bitcoin wallet backup.dat file is in my documents
but I'm not an advanced computer user
I have the complete bitcoin qt on my computer but don't know how to restore from the backup


texts:
I believe I know what is required to create block.

1.get previous hash(previous block is published)
2.collect transactions
3.proof of work(mining)
4.timestamped
5.audit by other nodes

Please tell me in what order these are done.


texts:
I have an Electrum wallet since Nov 2016 with some BTC.

It seems that I automatically own BCH now (is this right?). What is the simplest way to sell this BCH into BTC?

Should I install a BCH wallet software (Electron?), and initialize it with the same Seed as electrum (isn't this dangerous?)?

Or is there another simpler system to sell my BCH into BTC?


texts: Restoring from old paper Mycelium Wallet Backup

texts:
I have an old Mycelium Wallet Backup on paper, created July 2014, Mycelium Wallet 1.2.12., Backup Format Mycelium Backup 1.0. It used a 15-character password + checksum character, which I have.
It also lists Bitcoin address, and Encrypted Private Key - both in QR-code and in string of characters.
How do I go about restoring this wallet to a current wallet, be it Mycelium or some other one?


texts: Why is so expensive to buy Bitcoin with Credit Card?

texts:
There are many sites accepting credit cards to buy Bitcoin, but they charges a huge fee, sometimes is more than 10% (and I think never less than 5%).
Why is that? what is the problem with buying Bitcoin with CC? because usually buying via bank transfer has no extra cost.

I think could be related to some chargeback protection, but if this is the case, is not possible for example to block the "withdraw" of BTC from the seller account for a few days (or whatever is safe to avoid chargebacks)?

Sorry if it's duplicate but I couldn't find the answer neiter here nor google :(


texts: How exactly are Bitcoin's consensus rules enforced?

texts:
There are some rules called consensus rules, for example the block generation amount.
And it is said that "a change to consensus rules is a hard-fork".
But how exactly are the consensus rules enforced?
The internet says that the consensus rules are the rules that every full node follows. And every node rejects blocks that do not meet consensus rules "no matter what".
Ok.
But.
Must ALL of the full nodes accept? Or should MOST of the full nodes accept? Or is there some "holy full node" that must accept?
What if one controls 90% of all full nodes and decides to accept blocks with, say, 200 BTC/block? What if one controls 90% of the hashpower AND 90% of all nodes AND 90% of all full nodes?
Is full node software "signed" in some way to prevent modification to consensus rules?


texts: Can any current consumer grade computers mine any alt coins?

texts: I'm interested in mining and would like to know if there are any consumer grade computers available that can mine any of the alternative coins. If so, what computers and which coins do you think would work fairly well?


texts:
How can I set my miner to mine a specific block?
like:   Block: 496705

I have tried looking in ccminer options for that it looks like there is no option like that.


texts: Does the unique ID of an Armory wallet give any information about it?

texts:
I want to create an encrypted paper backup, and to do so I'm thinking about encrypting only the root key and the chain code, so that when I have to recover it, I don't have to type a lot.

But I'm wondering if leaving the unique ID unencrypted can give any sort of information about the wallet to the person who finds it, like what kind of pattern to look for, or how much bitcoin there is in the wallet.

For example, it's been said that for extra security, you shouldn't have your savings in a address if its public key is known, because in the future the private key could be found by using quantum computing or whatever. I know the unique ID is a different thing, but still I want to know what it is, how it is generated, etc.

Another way to ask the question: What do I need the unique ID for in the paper backup, if all I need to recover it is the root key and the chain code? Can't I just remove the unique ID from the paper backup? Would that be theoretically more secure?


texts: Is there any way to estimate an average amount of transactions per user per month?

texts: I would like to get a general picture about Bitcoin ecosystem development and dynamic changes, based on some numbers. Is it possible to have an estimate of a number of active users somehow? Preferably, based on the data from blockchain itself. Is it possible to estimate an average amount of transactions per user per month?


texts:
I'm looking at a bitcoin clone, not sure what codebase it was cloned from, but I've noticed that the listSinceBlock output sometimes includes:

a receive that has 0 confirmations
a send that has 0 confirmations
a send that has -1 confirmations

What is the significance of these counts? Does 0 mean that the transaction was never mined (too low fee?) versus the -1 meaning that that transaction has only ever been seen in a now-stale block? (chain reorg, new best chain doesn't include the block that held these transactions)

These transactions are fairly old (months) so if something was going to happen with them by now, i think it would have..


texts:
Trying to get my head around Bitcoin. Been watching tutorials, unsure if I still understand

Alice wants to send Bob 5 Bitcoins

Alice hashes the transaction with 5 Bitcoins and send's it to Bob's mailbox, i.e his Public Key

What is the job of the Miners?

Before the transaction get added to a public ledger (i.e blockchain) do the miners validates that Alice has 5 Bitcoins to give (based on info in public ledger) by recreating the hash.

And if validation is successful, the miners earn Bitcoins, the transaction is added to Blockchain, and Bob gets his 5 Bitcoins.

Is it true that validation takes about 10 minutes or so?

Really, I've been struggling with this concept.

Thanks!


texts:
So I have a VirCurEx account and I moved 1.5 BitCoins over to it... After the transaction was complete (like a day ago) I was checking and the website said "Balance - 1.5" which is correct but then for Available Balance it said "Available Balance - 0.74900001" or something close to that.

So I trade half of my bit coins in for other currencies (PPCoins, NameCoins, LiteCoins, etc.) and when I tried to trade more it wouldn't let me... Even though I have about .76 BitCoins left in the account (and I can withdrawal them if I want) the Available balance says 0.0001 (or something close to that, I'm not looking at it now)

Does anyone know what the difference is?


texts: How do I convert Public Key x value to y in Python and verify?

texts:
I have been using the BTC Address utility which enables me to type in something like:

020F031CA83F3FB372BD6C2430119E0B947CF059D19CDEA98F4CEFFEF620C584F9

Then clicking a button the program can spit out the Y value or tell me if that X value isn't valid (IE: doesn't have a valid Y value).

As an example, the result of this one would be Valid and would expand to produce the following:

040F031CA83F3FB372BD6C2430119E0B947CF059D19CDEA98F4CEFFEF620C584F9F064F1FDE4BC07D4F48C5114680AD1ADAF5F6EAA2166F7E4B4887703A681B548

Anyone know the code to do one, or both those functions in Python? (whether the code is for hexadecimal or decimal; it doesn't matter)


texts: What algorithm do miners (mining pools) use the generate different blocks as they exhaust the nonce values

texts:
As I understand it, the building of a block goes something like this (please correct):

Collect a bunch of new transactions.
Hash all those transactions.
Generate a coinbase transaction using the miner's (mining pool) public address.
Generate the Merkle root for all the transactions using an arbitrary order.
Fill in the block header.
Dispatch to mining hardware which will try all 2^32 nonce combinations.

Now, when the mining hardware says that there is no solution after trying all nonce combinations, it appears that it has the following options for generating new options to check:

Gather new transactions (or drop transactions), hash, and recalculate the Markle root.
Update the script (extranonce) field in the coinbase transaction (or the target address), hash, recalculate the Merkle root.
Update the timestamp in the header (what is the granularity on the timestamp).
Update the difficulty in the header (is this possible)??
Rearrange transaction order, and recalculate the Merkle root.

Are there any options I missed. What is the typical order that the mining pools do these things?
Thanks


texts: Connect Trezor (T) directly to a printer to generate paper wallets

texts: Is it possible for a Trezor or Trezor T to connect with and directly interface with a printer? The Mycelium Entropy device is very useful to print paper wallets while minimizing MITM attacks. I'd like the Trezor to do the same.


texts: What is NXT's Genesis Account's Passphrase / Password?

texts: I remember there was a passphrase/password that gave you access to NXT's genesis account even though you can't do anything with it once you get in there.


texts: Where do I get my username and password for solo mining?

texts: I downloaded Bitcoin-Qt and synched.  I downloaded pyminer to help me understand the mining process.  But I need a username and password.  Where do I get them for solo mining?


texts: How to perform automated mining in regtest mode?

texts:
I'm trying to setup a private network of bitcoin nodes for testing and experimentation. From what i understand, i have two choices while setting up a network:

I can run bitcoind -testnet and connect to the public test network. The testnet has nodes that will facilitate the mining of my transactions as long as i just broadcast them.
I can configure the node with regtest=1 and manually run the generate command whenever i want to create blocks.

I've also managed to find out that the mining is no longer a part of the core codebase and is usually in an external component.

What i don't understand is how any of these mining softwares interact with the bitcoin node. Does it periodically poll through the JSON RPC to check if the transaction pool has reached a certain threshold (in numbers or size)? If not, what triggers the beginning of a mining operation? Can the bitcoin node send out events when the transaction pool reaches a threshold?

I want to setup a similar automated process for creating blocks in my regtest network, but using the generate command instead of any mining software. I don't need a robust PoW setup in my local network. My aim is to just build an app which interacts with the nodes and makes transactions. Is writing an RPC client which periodically queries the pool size and fires a generate command on reaching a threshold the right way to proceed? Or does the bitcoin node itself provide some way to setup periodic generation of blocks?

Thanks in advance.

P.S. I'm very new to bitcoin development, so apologies if this is an obvious question.


texts: Bitcoind in test network doesn't display transactions

texts:
Hello i'm setting up the bitcoin-core daemon, i use version 160300 ( but it is same problem with newer version ).

I have made config like this:

testnet.conf

server=1
listen=50
listenonion=0
testnet=1
bind=127.0.0.1:18333
proxy=127.0.0.1:9050
rpcuser=bob
rpcpassword=12345
rpcport=18332
port=18333

datadir=/home/testnet/
pid=/home/testnet/.pid

then i run bitcoind:

bitcoind -daemon -conf="~/btc/testnet.conf"

Now i got me some address, using:
bitcoin-cli --rpcuser="bob" --rpcpassword="12345" --rpcport=18332 getnewaddress "test_user"

Result is 2NF9YinW7mqpUGy1GySD2xEV11uVPbQggbb

Then i go to this site https://coinfaucet.eu/en/btc-testnet/

I enter this address 2NF9YinW7mqpUGy1GySD2xEV11uVPbQggbb and press send, it gives me back transaction id, this is it here https://live.blockcypher.com/btc-testnet/tx/d2aa744b33e60f959217cf2ae3852f8826bb2d977839b4a2be0a958aec6a9984/

But i do now:

bitcoin-cli --rpcuser="bob" --rpcpassword="12345" --rpcport=18332 listtransactions

and in result get this:

[
]

No incoming transactions. getbalance returns 0

Can someone help. what is going on, do i need to mine blocks or something to get that transaction ? Or should i wait more for bitcoind to work ?

UPDATE:

The output of getblockcount is 1381543 and it seems to increase when i send getblockcount again

The output of getblockchaininfo is:

{
  "chain": "test",
  "blocks": 1381659,
  "headers": 1580289,
  "bestblockhash": "0000000000000095a7c30336ab1c9f12260b5a8fb2deb6dde59ab8c372376a64",
  "difficulty": 17349304.92883517,
  "mediantime": 1533662288,
  "verificationprogress": 0.8876421741980308,
  "initialblockdownload": true,
  "chainwork": "00000000000000000000000000000000000000000000008b05062dc0c9f9c122",
  "size_on_disk": 15923153327,
  "pruned": false,
  "softforks": [
    {
      "id": "bip34",
      "version": 2,
      "reject": {
        "status": true
      }
    },
    {
      "id": "bip66",
      "version": 3,
      "reject": {
        "status": true
      }
    },
    {
      "id": "bip65",
      "version": 4,
      "reject": {
        "status": true
      }
    }
  ],
  "bip9_softforks": {
    "csv": {
      "status": "active",
      "startTime": 1456790400,
      "timeout": 1493596800,
      "since": 770112
    },
    "segwit": {
      "status": "active",
      "startTime": 1462060800,
      "timeout": 1493596800,
      "since": 834624
    }
  },
  "warnings": ""
}


texts: how does merkle root building work for empty array?

texts:
It's known that even if no transactions get created, bitcoin still creates a block with empty array of transactions.
In this way, I am curious what the merkle root would be. How does bitcoin figure out merkle root for empty array ? if there're even 1 transaction in it, I understand completely what it does, but what about empty array ?


texts: When a difficulty change reaches the upper or lower bound (4x current), what is the implied impact on time per block?

texts:
Can someone work out the math that occurs with Bitcoin and Litecoin when the target changes to the hard coded minimum and maximum value, with respect to time?

In other words, if a lot of hashpower is added to the network and target increases by 4x, that is the upper bound.  How many blocks can be created right before the throttle of 4x is taken by the network?

I'm trying to calculate the affect throttling has on the number of blocks generated per hour.

Question

  What is the average time per block, right before the network adjusts to the 4x limit, when the hash power is added to the network?

If I were to guess, right before that 4x limit was reached, 1 block is generated every 2.5 minutes for Bitcoin, and 1 block every 45 seconds for litecoin.

Furthermore any hashpower added (or removed) beyond the 4x multipler will not cause a network adjustment and infinitely many blocks may be created in that interval.

Why I want to know this...

If a lot of hashpower is added to the Litecoin network, which already generates blocks (one every 2.5 minutes) then there will be more blocks generated, increasing the risk of a chain split.

I ultimately want to understand how the chain split will cause wasted computation by peers as their blocks are discarded by the longest chain.


texts: Recovering wallet after update to Btc core 0.13

texts: I updated my bitcoin core to 0.13 version and my wallet is empty and my transactions doesnt show anymore either. I've re scan .dat to make sure. How can I recover it ?


texts: Get the slush stratum proxy working on a mac

texts:
Title says it all - can anyone walk me through setting this up on a mac? I ran the linux python install script but i'm guessing i'm missing a few dependencies as it failed on me.

edit: there are numerous errors, listed here:

Reading http://tmrc.mit.edu/mirror/twisted/Twisted/9.0/
Download error on http://tmrc.mit.edu/mirror/twisted/Twisted/9.0/: [Errno 61] Connection refused -- Some packages may not be found!
Reading http://tmrc.mit.edu/mirror/twisted/Twisted/10.0/
Download error on http://tmrc.mit.edu/mirror/twisted/Twisted/10.0/: [Errno 61] Connection refused -- Some packages may not be found!
Reading http://twistedmatrix.com/projects/core/
Reading http://tmrc.mit.edu/mirror/twisted/Twisted/8.2/
Download error on http://tmrc.mit.edu/mirror/twisted/Twisted/8.2/: [Errno 61] Connection refused -- Some packages may not be found!
Reading http://tmrc.mit.edu/mirror/twisted/Twisted/8.1/
Download error on http://tmrc.mit.edu/mirror/twisted/Twisted/8.1/: [Errno 61] Connection refused -- Some packages may not be found!

Running Twisted-12.3.0/setup.py -q bdist_egg --dist-dir /tmp/easy_install-OQqo5N/Twisted-12.3.0/egg-dist-tmp-9vucfj
unable to execute llvm-gcc-4.2: No such file or directory
unable to execute llvm-gcc-4.2: No such file or directory
unable to execute llvm-gcc-4.2: No such file or directory
error: Setup script exited with error: command 'llvm-gcc-4.2' failed with exit status 1


texts: Failing communication with Bitcoin node: Only one usage of each socket address (protocol/network address/port) is normally permitted

texts:
I use the cryptean's BitcoinLib to make RPC calls to a Bitcoin node on another computer. Seemingly at random, the connection fails and I get a System.Net.Sockets.SocketException with the error code Only one usage of each socket address (protocol/network address/port) is normally permitted. I don't know if this is due to a race condition on the port number distribution on the local machine or a bug in BitcoinLib.

Here is the complete stack trace

2018-08-15 08:48:12.5570 Fetching transaction from Bitcoin node,
txid=3586d46be7bb1875fede4349849b89daf5ed73320979da211a54146c7bd90bfb.
2018-08-15 08:48:12.5831 Failed during communication with Bitcoin
node.
2018-08-15 08:48:12.5831 An unknown web exception occured
while trying to read the JSON response
2018-08-15 08:48:12.5831
System.Net.WebException: Only one usage of each socket address
(protocol/network address/port) is normally permitted Only one usage
of each socket address (protocol/network address/port) is normally
permitted ---> System.Net.Http.HttpRequestException: Only one usage
of each socket address (protocol/network address/port) is normally
permitted ---> System.Net.Sockets.SocketException: Only one usage of
each socket address (protocol/network address/port) is normally
permitted    at System.Net.Http.ConnectHelper.ConnectAsync(String
host, Int32 port, CancellationToken cancellationToken)    --- End of
inner exception stack trace ---    at
System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port,
CancellationToken cancellationToken)    at
System.Threading.Tasks.ValueTask1.get_Result()    at
System.Net.Http.HttpConnectionPool.CreateConnectionAsync(HttpRequestMessage
request, CancellationToken cancellationToken)    at
System.Threading.Tasks.ValueTask1.get_Result()    at
System.Net.Http.HttpConnectionPool.WaitForCreatedConnectionAsync(ValueTask 1
creationTask)    at System.Threading.Tasks.ValueTask 1.get_Result()
at
System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage
request, Boolean doRequestAuth, CancellationToken cancellationToken)
at
System.Net.Http.AuthenticationHelper.SendWithAuthAsync(HttpRequestMessage
request, Uri authUri, ICredentials credentials, Boolean
preAuthenticate, Boolean isProxyAuth, Boolean doRequestAuth,
HttpConnectionPool pool, CancellationToken cancellationToken)    at
System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request,
CancellationToken cancellationToken)    at
System.Net.Http.HttpClient.FinishSendAsyncUnbuffered(Task1 sendTask,
HttpRequestMessage request, CancellationTokenSource cts, Boolean
disposeCts)    at System.Net.HttpWebRequest.SendRequest()    at
System.Net.HttpWebRequest.GetResponse()    --- End of inner exception
stack trace ---    at System.Net.HttpWebRequest.GetResponse()    at
BitcoinLib.RPC.Connector.RpcConnector.MakeRequest[T](RpcMethods
rpcMethod, Object[] parameters)
2018-08-15 08:48:12.5831    at
BitcoinLib.RPC.Connector.RpcConnector.MakeRequest[T](RpcMethods
rpcMethod, Object[] parameters)


texts:
Each one of bitcoin and its derived crypto-currencies has a nonce value in the block, no matter what the algorithm is. Every miner tries to search for a luck nonce which can make the hash value smaller than the target under the required difficulty.

However, recently I search scrypt based cryptocurrencies, like the dogecoin and vertcoin block chain for few blocks. I found most of the nonce are even numbers, except for (only manually browsed in block explorer)

Block #184161 - nonce = 8dce5c01

Block #184143 - nonce = 2a674001

Block #184139 - nonce = 930aa899

many other blocks from the latest block (Block #184174) and blocks in between of them are even numbers. Moreover, many nonce value are in hex number of form XXXXXX00 (in an integer hex number form, it is stored as 00XXXXXX in block), or multiples of 256.

The same outcome I observed in Vertcoin blocks. I manually traversed for few blocks and also found nonces of them are also even numbers.

I'd like to ask a question. If I configure the scrypt or n-scrypt to search only even numbers, is it possible to have higher chance to find the nonce which can solve the current quickly?

BTW, I won't expect the mining revenue of each miner in the pool (PPS or PPLNS) is going to be greater than that of normal nonce searching algorithm because the pool count for "shares" you found. When you skip odd numbers, you also lose the chance to get a share (solved by the odd nonce) which can meet the diff the pool gives to you. However, when a pool found a nonce that can solve the block, then the pool wins and gets the rewards.

Edited: Apr 18

I wrote a small program to collect some statistical data. From recent Dogecoin block #186,299 to #145,000 (the last mandatory update)

total 41,300 blocks

number of odds = 3,891  (9.42%)
number of evens = 37,409 (90.58%)

ratio of odd to even is about 1:10

Among the evens, the number of multiples of 256 = 35,106

85% of total
93.866% of evens

Update: 4/20

I recently also checked the nonces from block 552,780 to 253,898 of Litecoin.

totally 298,883 blocks.

number of odds = 42,963 (14.374521%)
number of evens = 255,920 (85.625479%)
Among the evens, the number of multiples of 256 = 225,746

75.529890% of total

Update: 4/21

I use a small Perl script and call litecoind/dogecoind wallet to print out each block's nonce. It is very slow but quite simple. It would be very fast when you are using binary block database parser.

#!/usr/bin/perl -w

my $odd = 0;
my $even = 0;
my $m256 = 0;
my $total = 0;
for ($i = 186299; $i >= 145000; $i = $i-1) {
    $nonce = `dogecoind getblock \`dogecoind getblockhash $i\` | grep nonce`;
    chomp $nonce;
    $nonce =~ s/[^0-9]*//g;
    printf "%d %d\n", $i, $nonce;

    if (($nonce %2)== 1) {
            $odd++;
    }
    else {
            $even = $even + 1;
            $m256++ if (($nonce % 256) == 0);
    }
    $total ++;
}
printf "odds=%d (%f%%) evens=%d (%f%%) 256s=%d (%f%%)\n",
     $odd, (100.0*$odd/$total),
     $even, (100.0*$even/$total),
     $m256, 100.0*$m256/$total;


texts: How to Transfer Real BTC From My Wallet to another account using C#

texts:
Hi I wanted to send BTC from my wallet to another wallet through any C# Library. Currently i am using NBitcoin Library to perform this action. But, i am not able to get through it.
Thanks


texts: Is it possible to buy half of a full bitcoin?

texts: I've noticed that certain products online do not require a full bitcoin to purchase. My question is do you need to start with one full bitcoin in order to make a purchase of such items?


texts: Did Satoshi Nakamoto Really Publish A Second Paper In December, 2015?

texts:
http://bitcoinnewschannel.com/2015/12/27/page-2-of-the-hash-tube-signature-scheme-credited-to-satoshi-nakamoto/

The guys working at this site claimed that Satoshi Nakamoto sent them a paper titled (hash tube signatures) which you can read via the link.

The problem is those guys that work on that site have been around the bitcoin community since 2009-2010 and some thought they invented bitcoin, so did they make this up? or is it really Satoshi?


texts: what is blockchain.info testnet api url?

texts:
there is a testnet for blockchain.info here but I can't find a url for calling api(s) in testnet as such we have in main network

on main network
https://api.blockchain.info/v2/receive?xpub=$xpub&callback=$callback_url&key=$key

and for example on testnet
https://api.testnet.blockchain.info/v2/receive?xpub=$xpub&callback=$callback_url&key=$key

is there anybody know where the testnet api url is?
Thanks,


texts: Bitcoin -> prepaid VISA/Mastercard service (2014 edition)?

texts:
I have read the answers in this question here... But it is incredibly outdated. OKPay no longer accepts Bitcoin to creditcard. bitcashretail.com is down. xmlgold.eu results into an error. Centregold results into a page not found. ecardone.com is seized by the "Global Illicit Financial Team"
Etc, etc, etc...

So I think it is time for a new edition of the bitcoin to virtual creditcard question.


texts: Is there a way for me observe network traffic of bitcoin exchange?

texts:
I was wondering if there is a way to observe a network traffic/packet of bitcoin exchange. I want to know what's in the packet when I send a bitcoin from one wallet to another.

Thanks.


texts: How does an ASIC Bitcoin miner work on a fundamental level?

texts: I'd like to understand how ASIC miners are more efficient at mining bitcoin. Having a background in CS, how does the ASIC miner work on a binary level on the CPU and why is it so much faster?


texts: How to setup a DNS Seeds node and a Seed Node (for Litecoin clone)

texts:
I'm doing this for study purposes (creating a Litecoin clone). I read somewhere that for SCRYPT clones, the DNS Seeds nodes aren't necessary?

If I do need them, how to I setup these nodes. I know a DNS Seed node contains a list of IPs that are running a bitcoin client (in my case an alt-coin client).

Or is it enough to hard code one or more Ips in the client itself? Can I use a VPS for this?
Sorry for being noobish ;-)


texts: Can I replace the fans in a Zeus Hurricane x3?

texts:
This thing sounds like there is a jet waiting to take off in my office.

Can I replace the fans with quieter ones? If so, can you recommend which fans to buy to replace the stock ones?

Thanks!!


texts: What are the transactions included in the merkle root

texts:
I am trying to understand the block hashing algorithm used to generate block.

One of the points mentioned here is

  it is (nearly) impossible for two people to have the same Merkle root because the first transaction in your block is a generation "sent" to one of your unique Bitcoin addresses.

How do I specify my unique address? Does it depend on what kind of miner I use and whether I mine in a pool?

Also what is "generation" and how is it different from other transactions that include transfers of bitcoins? What other transactions are included in the Merkle root?


texts: My transaction hasn't confirmed and it's been 9 days

texts:
Transaction was initiated May 16, fee was 0.0001 and it's 226 bytes. It's 9 days later and it hasn't confirmed.

What is going on?
How do I get my BTC back?

EDIT:

Sorry, since I posted as guest it seems to not let me respond/edit as original poster. Here's the blockchain info: https://blockchain.info/tx-index/836b863d4099493d5599ab20024b10d6087f0ea662ffd2d1feea54acbd4a1195

It says May 20th, but I did send it May 16th


texts: Energy & performance comparison: GPU mining vs playing HD Video

texts:
Using the built-in ATI video card on my computer, I can mine at about a 30-50 MHps rate. I'm wondering, how does this amount of work compare to normal video card operation? Or how can it be calculated? Is mining for 6 hours at this rate equivalent to watching Transformers 2 in HD over and over again on my monitor?

There's already plenty of questions about equipment wear when GPU mining, I'm looking for an easy-to-understand comparison to normal GPU taks.

Thanks


texts: Whats the difference between "txid" and "hash" - getrawtransaction bitcoind

texts:
Sometimes the txid key is the same as the hash key in the return of getrawtransaction, sometimes different. I'm trying to understand more about these...

What are the differences, and why are they sometimes identical and sometimes different?

Example - identical in this testnet tx:

bitcoin-cli -testnet getrawtransaction c3f11d1708ac20eff9137d4eadd62dd99d71ce22dc51bc51d4e5b83958d9596d 1

Example - different in this livenet tx:

bitcoin-cli getrawtransaction df2fd78e42590f301b5174e7d6665887380ad1f49a4688a0f8adffa0829855cc 1


texts: Can sidechains be used for fiat currencies?

texts:
How could sidechains be used for auditing fiat transactions?

How would the accounting transaction in fiat and the record in a journal be merged?


texts: Where should a miner get the most current block from?

texts:
Where does a miner get the most recent/current block from, to work on confirming new transactions and building the next block?

Obviously it's the 'top' block on the blockchain - where can a new miner 'get' the blockchain from? As I understand it, it's P2P, but how do you connect to those peers in the first place?


texts: How to configure multiple miners on a single network laptop/router?

texts:
I have 2 S9's, a router and laptop.

Do the S9's have separate IP addresses or just one network IP for both miners? I realize this sounds stupid, however, I cant figure out how to apply 2 IP addresses to the Bitmain s/w set up. All the set up examples only show 1 miner.


texts: How to enumerate all blocks/transactions in order with bitcoind?

texts: Is it possible to enumerate all blocks/transactions, in order, using bitcoind API? The listsinceblock call seems to return the transactions without any ordering so assuming I get a very long list, I cannot process half of it, store last processed block hash and later ask again for transaction since that block.


texts: What could stop bitcoin-seeder from "hearing" DNS queries?

texts:
I'm running several bitcoin-seeders. Under Ubuntu 14.04 & 16.04, they run fine and answer queries.
On Ubuntu 18.04, however, dnsseed does not detect the queries sent to it.  I know the machine is receiving the query because DNS requests are monitored with dnstop, and every DNS query sent with 'dig' is sensed by dnstop and reported, but dnsseed shows "0 DNS Requests".
There is no firewall running and apparmor has been disabled. What tests could be run or troubleshooting strategy followed to find the problem ?

Under Ubuntu 16.04:

Loading dnsseed.dat...done Starting 4 DNS threads for ra.zmark.org on
173.255.252.140 (port 5353).......done Starting seeder...done [18-10-24 19:27:41] 274/37963 available (1258 tried in 1000s, 38980 new, 1536
active), 0 banned; 3 DNS requests, 3 db queries

Under Ubuntu 18.04:

Supporting whitelisted filters: 0x1,0x5,0x9,0xd Loading
dnsseed.dat...done Starting 4 DNS threads for shido.bitmark.one on
139.162.122.138 (port 5353).......done Starting seeder...done Starting 96 crawler threads...done [18-10-24 19:25:23] 3593/87930 available
(64497 tried in 3805s, 21897 new, 1536 active), 1 banned; 0 DNS
requests, 0 db queries

dnstop:

Queries: 0 new, 1363 total                                                                                Wed Oct 24 19:39:03 2018
Replies: 0 new, 191 total

Query Name                     Count      %   cum%
-------------------------- --------- ------ ------
shido.bitmark.one               1169   85.8   85.8
bitseed.xf2.org                  117    8.6   94.4
org.members.linode.com            24    1.8   96.1
seed.bitcoin.sipa.be              20    1.5   97.6
dnsseed.bitcoin.dashjr.org        14    1.0   98.6
dnsseed.bluematt.me               12    0.9   99.5
motd.ubuntu.com                    5    0.4   99.9
github.com                         2    0.1  100.0


texts: Unknown factor in bitcoin pool breakdown

texts:
Some time ago the breakdown was dangerously close to heaving too heavily towards Deepbit with only a small part unknown/single person miners. Now there's a 34% unknown factor.

What caused this? Are these botnets? People deciding their amortised profit stablises anyway? A drug cartel laundering money?


texts: is it possible to launder bitcoin by exchanging it for litecoin and then back to bitcoin?

texts:
The scenario I was thinking of was I have some bitcoin from doing Bad Things (TM) that I want to launder.  I could register with kraken.com and trade only virtual currencies with the L1 verification ( un/pw, country of residence, phone ).
Process

deposit dirty BTC
buy LTC
transfer to another LTC address
transfer back to another kraken account.
buy BTC
transfer BTC to another exchange that I have linked to a bank account
cash out BTC

What issues do you see with this?  From what I understand kraken.com only has a un/pw ( easy to create a throwaway ) country of origin ( no verification, can lie ) and phone ( easy to buy a burner ).  And even that isn't public knowledge.  Once I transfer to LTC those litecoins are now clean.  Does that make sense?  There is no link between BTC sold and LTC bought except for at the exchange and that only has untraceable details ( un/pw/fake country of origin/burner phone)


texts: Failing to send a testnet transaction manually

texts:
I use Ken Shirriff's post on how to manually create and send a transaction, and I tried to adjust it to work with testnet.
AFAIK after adjusting to the testnet addresses, no further adjustments should be made in the tx creation and signature process.

However, my transaction does not work...

I successfully connect to peer 185.28.76.179:18333, send the transaction but nothing happens.
What should I do to figure this out?

Here is the raw tx:

010000000142ad1ac9d0214d326a9f5f4e0051bb6f0e197bb7bf0661266623f865a1a38d10000000008b4830450221008e434d7e6e0dc3741d99142b1fdb3a6eeba7a6d1d1e95e1aa90dcb638fc17c7b0220179a9004bac06ac64914af1e9f29db3a7cb50942bf3e865a23727151f3bbd6330141047bc52c13eacc1adcb1eea06317760537947d67a9208351e4c213bed82f0ce843249c9675e5f28ca4b0848036118a43defa8b6c5d5d77250ac8709eca8f88e30bffffffff017b000000000000001976a9149437a39c0ddd64205002c3f9adda6bb77df1be8288ac00000000


texts: Can the 51% attack be made to become 81% attack or 91% attack?

texts:
Since the 51% attack happens if there are more than 50% of nodes that fake the data on the blockchain, can it be actually 81% or 91% that is needed to fake the data, because it would be much harder if more than 80% of the nodes are "bad guys".
So what I mean is, can it be the case that even 79% cannot be an attack, but need to be a higher number, such as 81% or 91%.
It may appear if the verification of data can reach a 50% level, reaching out to 1 more node of those 50% can make it become 80% to 100% easily, so one extra step is all it takes?


texts:
From what I can tell OP_DROP is a method of storing non validation data in a tx ( seperate from using data after OP_RETURN ).

However in this unlocking script described by bip199, the timeout block and timeout op are before the OP_DROP, meaning they would be dropped during validation? OP_DROP can't be describing what comes after because that should be the payment path validation - and because afaik bitcoin script is stack based.

What is the point of OP_DROP? How does it apply in the following script?

OP_IF
    [HASHOP] <digest> OP_EQUALVERIFY OP_DUP OP_HASH160 <seller pubkey hash>
OP_ELSE
    <num> [TIMEOUTOP] OP_DROP OP_DUP OP_HASH160 <buyer pubkey hash>
OP_ENDIF
OP_EQUALVERIFY
OP_CHECKSIG


texts: BitInstant - How do I trade my plain cash for Bitcoin at CVS, 7-11, Walmart

texts: On the BitInstant site, it says that I can trade in my paper money at places like CVS, 7-11 and Walmart and get bitcoins sent to me in the next 30 minutes. Can some explain how this works and what I have to do. Do I just go up to the clerk a 7-11 and hand him my invoice i recieved at BitInstant.com and I will get my bitcoins?


texts: I recently purchased some bitcoins, which were sent via coinapult to my cell phone.  I received a text for the amount with a link to an online wallet (apparently not a true wallet but just an account within a larger wallet).  I would like to have my own wallet.  I’ve downloaded the bitcoin wallet program (for windows) from this website.  (bitcoin-qt) version 0.6.2-win32.  When I open this program it claims to be “synchronizing with network” a certain number of “blocks”.  In the “received  coins” tab is listed an address.  Using my coinapult via the link provided on my smartphone I sent a bitcoin to the listed address.  However I see no evidence it was received.  Do I need to wait for the synchronizing process to complete to send bitcoins to this wallet?


texts: CVE-2012-2459 , possible code and performance improvement, is my logic correct?

texts:
ok so, in my effort to create a fullnode from scratch both for learning purpose and need (not a topic for discussion, thanks), I was looking at the code that check Merkle Root to not be vulnerable to CVE-2012-2459.
That vulnerability basically allows you to create a block that has a valid merkle root but contains duplicate transactions, causing a node that receive such block before the correct one, to be stuck on a fork (because that block will be flagged as incorrect and having the same hash of a correct block will prevent the node to ask again for that block, causing a node to be stuck.
Anyway, this is an old CVE that was fixed back in 2012 and code changed during time.
Now in bitcoin core the code is not that pretty and the method to compute merkle root are polluted from a boolean parameter that when read back reflects if the block has been mutated (malleated) or not.
The code is this
uint256 ComputeMerkleRoot(std::vector<uint256> hashes, bool* mutated) {
    bool mutation = false;
    while (hashes.size() > 1) {
        if (mutated) {
            for (size_t pos = 0; pos + 1 < hashes.size(); pos += 2) {
                if (hashes[pos] == hashes[pos + 1]) mutation = true;
            }
        }
        if (hashes.size() & 1) {
            hashes.push_back(hashes.back());
        }
        SHA256D64(hashes[0].begin(), hashes[0].begin(), hashes.size() / 2);
        hashes.resize(hashes.size() / 2);
    }
    if (mutated) *mutated = mutation;
    if (hashes.size() == 0) return uint256();
    return hashes[0];
}

now thinking about the problem, I think I found a better approach that is O(log n) and way better both in readability and speed... if it works and the logic isn't flawled... so I'd like to know your thought about this.
my paint skill can show you some of the logic:

A, B, C... etc... are transactions
the vertical line is what I call "safe point", basically all transactions before that safe point are guaranteed to be not duplicable (this is one of the assumption I do and one thing to check if it's correct)
then, based on how merkle root is computed and how the CVE uses that to do nasty things, you can see some example of malleated blocks
I created then a gist, containing a LINQPad code that can be run as it is and produce outputs to see if the logc is correct and can spot malleated blocks.
https://gist.github.com/MithrilMan/27985e4f5bcc3853e792aa39631b9647
this is an output example of that gist

The core logic relies into checking the last transaction against the previous, moving exponentially to the left at each iteration (see the picture with the vertical blue arrows showing which element it checks, or see the linqpad result where it's explicitly detailed)
I handle both the cases where the tx count is even or odd.
To me it seems to work but would like to have some more eyes on that to see if the logic sounds correct or not.
Note how for 9000 tx I have just to compare 14 transactions instead of thousands like current bitcoin code is doing.
Apart from that in my case it has another pros that allow me to split the markle computation and markle cve check in two different places, without having to use a solution like that mutated boolean parameter
UPDATE
for those of you not having LINQPad I adapted the POC script to be run on dotnetfiddle here
for those who doesn't have linqpad I adapted the script to be run on dotnetfiddle here
https://dotnetfiddle.net/wT87D2


texts: How to set up LndHub on top of RaspiBolt ir RaspiBlitz?

texts:
My goal is to support multiple LN clients without having to run a full node for each client.

How to set up LndHub on top of RaspiBolt or RaspiBlitz?


texts: Is it possible to shift/modify a ECDSA keypair by a scalar where the public key can be computed using only public information?

texts:
I am looking for a method which would allow a keypair to be modified in a manner which is unpredictable to the original creator.

So I was thinking a user creates a key and commits it by making a transaction which is written to the blockchain.  The block hash could be used as a source of unpredictability to derive a new keypair.  Can this be done in a manner than only the derived private key can be computed from the original private key and the derived public key can be computed without the original or new private key?

Let:

k = existing private key
K = existing public key
B = hash of block hash
k' = derived private key
K' = derived public key

Is there some pair of functions such that solves the following?

K' = FPub(K, B)
k' = FPriv(k, B)

Are there any security implications?

To be clear the new public key should be derived using only public information (existing public key and scalar).


texts: Choosing a blockchain fork in Bitcoin Core

texts:
According to this, the BIP 148 UASF (user activated soft fork) goes into effect on August 1. Supposing it results in a substantial fork in the blockchain, is there a way users of Bitcoin Core can choose which chain to use (as opposed to whichever chain one's node receives first)? In other words: How do I tell Bitcoin Core to use an alternative chain?

Is this what preciousblock* is for?

*"Treats a block as if it were received before others with the same work."


texts:
Hello fellow bitcoiners,

I would like to install lightning over Bitcoin core - I already have a full node. But every guide I follow ends up with a broken build or some issue preventing to finish the install of lightning. Did you have success with a good howto by any chance? I would preciate if someone could post a proven working install howto.

Thank you very much, /cr!?ptal


texts: How will Bitcoin deal with the year 2106 problem?

texts: The Bitcoin protocol currently uses uint32_t to record timestamps. While the year 2106 is still a long way off, I'm wondering why not just go with int64_t and be done with it?


texts:
From here, we can read that :

  A private key is a 256-bit value, meaning there are approximately
  1.1579e77 possible keys (There are about 1.2288e66 invalid values

But here, we have :

  Nearly every 256-bit number is a valid ECDSA private key.
  Specifically, any 256-bit number from 0x1 to 0xFFFF FFFF FFFF FFFF
  FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140 is a valid
  private key.

Does "nearly every" mean (1.1579e77-1.2288e66) out of 1.1579e77 ?


texts: Are lightweight LN wallets vulnerable to transaction withholding?

texts: As far as I know, LN requires the user to watch the blockchain in order to perform penalty in time. However, running full node is probably a heavy burden to some users, especially to mobile phones. I once heard that improved protocol for lightweight wallet (like Neutrino) can solve this problem, but I also heard that such lightweight wallet protocol still implies trusting the full node or server which provides service. Especially, a malicious full node can hide transactions from its clients, which seems to be a potential threat to lightweight LN wallets.


texts: Resource on cryptocurrency exponents/significant digits/decimal places?

texts: I'm looking for a comprehensive list, or library, that lists a wide range of cryptocurrencies and there exponents/significant digits/decimals - ie "8 for BTC, 18 for ETH, ..."


texts: I think my bitcoin wallet was hacked. What to do?

texts: I opened bitcoin-qt after not mining for a couple months and found that I suddenly have no more bitcoins!  And I see that there were 2 transactions that I did not authorize sending my coins to other addresses!  Is there anything I can do to get my coins back?


texts: What are Bloom filters and why does Bisq require them to be activated on my local node?

texts:
First of all, why does Bisq care about Bitcoin Core being installed or not?
Then why does it require it to be fully synced and not pruned?
Finally, the error message talking about "Bloom filters" is confusing me, what are they and why does Bisq need them ?


texts: How many confirmation do i have to wait before i can spend the inputs I already received?

texts: Can I spend Inputs with 0 confirmations?? If I could, are there some restrictions?


texts: Why are there such huge differences between commissions on different exchanges?

texts: Why are there such huge differences between the commissions applied by sites like Bitstamp.org (0.5-1%) and other sites (I have seen 5-10% fees)?


texts: Bitcoin Qt message signature construction

texts:
I'm trying to construct the message verification signature of bitcoin qt in python. I'm able to compute the couple (r,s) of the signature, but, even I'm not able to find the correct way to encode it to find the correct base64 encoded string that bitcoin-qt use.

Here is my example :

My test bitcoin addresse : "1BBwZVdBjoPxotHfrKLpHJBSy7vmc2pjex"
Private Key : 18 (the integer 18 in base 10)
Message : "Hello World"

When I sign, I use an integer k (specified in the ECDSA) which is 1 (just an example).
I get (r,s)=(55066263022277343669578718895168534326250603453777594175500187360389116729240, 23952895512439370531107719399796920806315532907434078350311186283065887977941)
in base 10.

How do I construct the signature string generated by bitcoin-qt from these r and s ?

Thank you very much for your help.


texts: Getting orphaned Blocks from the Blockchain

texts:
I'm very interested in doing some analysis of orphaned blocks, but to do so I'd have to have a good way of accessing them. Blockchain.info seems like a good place to start but I don't want to abuse their API by scraping the entire Blockchain. Another attempt was to use ABE but after parsing nearly all the blockchain from my Disk (several days of work) I am unable to find a single orphaned block, and I'm starting to fear that the satoshi client prunes old orphaned blocks, which would be a pity.

Will I be able to find orphaned blocks with ABE, and if not what alternatives are there?


texts: What is the currently most efficient and reliable method to store the Bitcoin blockchain in a local database?

texts:
I have seen several posts on this before, and have tried all the suggested solutions, but I can't get any of them to work.

I am interested in analysing transactions with the OP_RETURN opcode for a project, and need to dump the entire Bitcoin in a database to start working on that. I have already installed Bitcoin Core and downloaded all data until today.

There is a list of tools available to do this, and I have had problems with all of them:

WebBTC: The files don't seem to be available
BitcoinDataBaseGenerator: This seems like the most promising solution, as it is easy to set up on Windows, and a MS SQL Server database is easy to use. However, after file blk005**.dat it crashed, saying that there are blocks with an unknown version. I also can't try to run it again because the queries to delete data from that file won't finish executing and timeout after ~2 hours. Looking at the issues at GitHub, people seem to be having problems with that too, as the repo is not maintained any more.
Blockparser + SQL: This only keeps the data in memory.
BitcoinABE: I have not tried this one yet. I read many issues that it is very slow though, and there are generally many open issues. Might work though, I will try later.
NBitcoin.Indexer: Made for Azure, I want to have a local database though.
Blockchain2Graph: This also seems promising, and it is under active development. It uses neo4j, which is fine. At the moment I have no preference for either SQL or graph databases. I set up a Debian Virtual Machine and followed all the steps, which did work. However, at the end I can't get the application to actually show up in the browser. From my understanding it uses RPC calls and not the blk*.dat files directly.

Then I found one more on Google:

Bitcoin-to-neo4j: This takes the block files directly and puts them in a neo4j database. The problem with this is that the database is apparently six times the size of the actual Bitcoin data. I don't have 1.7 Terabytes of free storage space available. It also mentions that it takes several weeks to process it all. I simply don't have the time to wait for that.

So, my question is if there are any other tools currently available to easily write the Bitcoin blk*.dat files to a local database. Maybe I did something wrong, with the above mentioned solutions, but none of them seem to be an ideal solution. How easy would it be to write a custom application that only extracts the data I'm interested in, and are there code templates for that?


texts: Transfer from exchange to my Electrum cold wallet

texts:
I have created a wallet on an offline computer and regenerated it as a watching-only wallet on my online computer using the public key of the offline computer wallet.

So far, so good. Now, how can I transfer my bitcoins from the exchange service to the cold wallet? Is it fine to just enter the first address I get when clicking the "receive" tab on the online computer (watching-only wallet), will bitcoins transfered to this address also 'arrive' in my cold storage (offline computer) wallet original?


texts: Bitfinex API - clarification of "timestamp" in orderbook API request

texts:
Does anybody know what value "timestamp" in orderbook POST actually means?

The response is structured as follows:

bids (array)
price (price)
amount (decimal)
timestamp (time)
asks (array)
price (price)
amount (decimal)
timestamp (time)

documentation: Bitfinex API

Does it say when the corresponding limit order entered the orderbook? Assuming that this is true, what if there are two limit orders at the same price level each of which entered the orderbook at different time? Will there be two orders at that price level or will it be groupped to one order with the latest (more recent) timestamp?


texts: Why does the default miner implementation use pay-to-pubkey?

texts:
Looking at the v0.9.3 source in miner.cpp:

CBlockTemplate* CreateNewBlockWithKey(CReserveKey& reservekey)
{
    CPubKey pubkey;
    if (!reservekey.GetReservedKey(pubkey))
        return NULL;

    CScript scriptPubKey = CScript() << pubkey << OP_CHECKSIG;
    return CreateNewBlock(scriptPubKey);
}

The default scriptPubKey is a pay-to-pubkey? Does it need to be preserved for compatibility? I'm just surprised that it's not using pay-to-pubkey-hash.


texts: How do I move money from one address to another on the same wallet?

texts:
My wallet have 3 addresses. I want to consolidate payment into one.

What should I do in bitcoin-qt.

Notice on the SAME wallet. I know how to do this if the addresses are on different wallet.

I just don't want to keep moving wallets because I have backups on those wallets.


texts: For a transaction with a single input and output, is there a difference between SIGHASH_ALL and SIGHASH_SINGLE|SIGHASH_ANYONECANPAY

texts:
I have an signing implementation that already works for SIGHASH_ALL, and I'm trying to also support SIGHASH_SINGLE|SIGHASH_ANYONECANPAY.

I'm referencing https://en.bitcoin.it/wiki/OP_CHECKSIG for the behaviors of different SIGHASH types. From my reading, I assumed that there should be no difference between SIGHASH_ALL and SIGHASH_SINGLE|SIGHASH_ANYONECANPAY (aside from the hashtype appended to the end of the transaction being hashed) if the transaction involved only has one input and one output, but from my testing using other tools this does not seem to be the case.

Am I wrong with my interpretation? What modifications would the signing need if it's SIGHASH_SINGLE|SIGHASH_ANYONECANPAY instead of SIGHASH_ALL, assuming there's only a single input and output?


texts:
The reason I ask is because I just received an e-mail from someone who claims to have commandeered my cell phone camera and also my address book.  They said they would overlay my picture while watching
porn if I do not send them 869 usd worth of bit coins, or the will send my customized video to everyone in my address book.  The email header didn’t have any IP addresses or a MAC address.  The email address itself would not resolve to a valid domain. If anyone can help me find the owner of this bit coin address I would really appreciate it.
BTC address: 1Lq8TnU33SMFUXcyGYmwkfriaBAfEoX5Co
Thank you very much.
David


texts: How does one calculate the profitability for a coin?

texts: Given, a coin has difficulty 'd', an exchange rate 'x'/BTC or 'X'/USD, and given that my hardware can do 'y' MH/s (scrypt), how would I determine the best coin that I could mine? Do I need to consider any other factors?


texts: How could recurring payments be implemented?

texts:
I pay for some things on a regular basis. They generally fall into two categories:

Things I pay for or lose, eg a variety of online services (Spotify for example)
Things I'm legally obliged to pay because I've signed a contract (my mobile bill, for example)

In the first case, I suspect recurring payments could be handled relatively easily with upgrades to the original client interface. (Maybe it would be complicated by the desire to have a new address per transaction.)

In the second case, the other party has a stronger vested interest in knowing they will receive the money. Currently, with bank standing orders and direct debits, nothing stops me cancelling regular payments on my end. But companies who receive the payments rely in part on knowing I have to go out of my way to do that. They also rely on knowing that my wages likely go into the same bank account that their payment comes out of.

With Bitcoin, the situation is reversed. I have to go out of my way to make a recurring payment. Even I was using some online service ("Bitcoin bank"?) to make the payments, I'd still have to go out of my way to top up the balance.

With no changes to Bitcoin, if it became a dominant currency, I would predict an increase in the use of debt collection agencies to recover missed contract payments. Good for debt collection agencies, but it would drive up the cost of the services proportionately.

How could recurring payments be implemented in a mutually satisfactory way? Or is the current system inherently impossible to recreate with Bitcoin?


texts: Applying additional oauth scopes to coinbase

texts:
I am trying to apply the coinbase wallet API with oauth to use its send functionality. I have been able to connect to the API and use its endpoints, but whenever I try to use the send functionality, I am thrown the error Invalid amount for meta[send_limit_amount]. My omniauth initializer looks like this:

provider :coinbase, , ENV['CLIENT_ID'], ENV['CLIENT_SECRET'],
scope: 'wallet:user:read wallet:user:email wallet:accounts:read wallet:transactions:send'

The reason for this error is because, in order to use the send functionality, coinbase requires additional parameter meta[send_limit_amount]. Where and how am I supposed to apply this additional scope?


texts: Can I send a transaction with zero fees? And if I could, what would happen? Would miners ignore my request? Who sets the price of fees for transactions?


texts: Is there any blockchains that has implemented a 2fa type of security measure?

texts:
Currently someone can steal your btc private key and send all your funds away. But has there been a 2fa built into a blockchain that prevents something like this?

Say if you wanted to send something out from a btc address, it will require a 2fa generated token text to be provided in order send out.

I'm not talking about exchanges, but just the blockchain itself.


texts: How does the wallet work, online and offline?

texts:
I've been reading about bitcoins and I've come across a few questions:

How does the wallet actually work? From what I can gather, I use the wallet as a centralized service to store recieved coins, and to send coins. If recieved coins are stored physically in the .dat file, what are the safeguards that prevent users from duplicating the .dat file and getting more coins?
Do I need to have the wallet client on to receive transactions? In other words, if i don't leave the wallet client active on my computer, will i be able to receive transactions the next time i open the wallet?

Cheers.


texts: Why was transaction malleability fix required for Lightning network?

texts:
Transaction malleability is that TXID can be changed modifying the signature slightly without the private key. To implement Lightning Network, it was required to fix the malleability.

However, I thought that we just wait for 1 confirmation that we create an opening transaction, which is 2 of 2 Multisig, in order to open a channel.

After researching Lightning network protocol, I kind of found out that before broadcasting the opening transaction, we have to create a commitment transaction that needs the TXID of the opening transaction, and we have to keep it to claim. If the TXID is changed, the commitment transaction won’t be valid. So we needed to fix transaction malleability to keep the commitment transaction valid.

Is this correct? If not, please educate me.


texts: Can one recover the full list of public keys generated in electrum with the seed/private key?

texts:
I used the wallet.change_gap_limit command in the electrum console in order to generate some 20.000 public keys.
Would I be able to recover all of these using my seed after completely removing electrum from my system, reinstalling it and running the change_gap_limit command again?


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

texts:
I tried to create a multisig in both the Bitcoin network and the Bitcoin testnet. It seems to work only when all public keys are from the current wallet. That means when I call listunspent after I send coin to the multisig address, it didn't show up as a multisig address unless this multisig address was created from the current wallet. I tried it in both real coin and testnet. What is problem?

Note: I use Bitcoin-qt 0.9.2.1

Why "listunspent" dosen't show multisig address ?

How can i check balance of multisig address and get txid and vout and scriptPubKey for multisig address ?

Edit 2:I try to search for software(tool) can be track bitcoin address (balance and transactions) i found bitcoin-abe, but  when i search for it i found i can't search for bitcoin address to retrieve it balance and transaction ? anyone know tool like blockchain when i request about bitcoin address give me balance and transactions ?


texts: Is there any way to make an UTXO that cannot be spent until a certain block #?

texts:
In bitcoin, each transaction has an nLockTime integer to specify the earliest allowed block number/time that the transaction can be added to the blockchain. In addition, each transaction input has an nSequence integer that could theoretically be used to update transactions and know which is the most recent (although this functionality is currently disabled).

But is there a way to broadcast a transaction which is final and can be added to the blockchain immediately, but also make it so that its outputs cannot be spent until a certain block number/time? It seems like this would be a useful feature. For example, if I want to give my inheritance to be made available at the time my grandson/granddaughter turns 18, I don't think there is any way to do that in bitcoin except have someone hold the funds and give them to them at the time. Or if I wanted to give someone an allowance, I could just send funds at once for 3 months or so, and they would just show up in the son/daughter's wallet on a weekly basis.

So, just to double check, there's no way to do something like this in bitcoin, is there? Are there any security risks by allowing transactions like this? If there really isn't any way to do this, then maybe it's something to add to the hard fork wishlist.

If there is no way to do this with Bitcoin right now, is it because there is a serious flaw with such a system where an UTXO could be added to the blockchain that is not YET spendable?

I can think of two ways that such a thing might be implemented.

Supplement the bitcoin scripting language with OP_BLOCKINDEX and OP_BLOCKTIME opcodes, which just push the corresponding value onto the stack. These values would have to come from the block that spends the UTXO, though, not from the the block that included the transaction that created the UTXO. This would mean that any transaction outputs with these OP codes could not be spent with 0 confirmations, because these OPs would have no meaning in this context. (This method possibly adds too much complexity to the situation)
Or, similar to the nSequence field, we could add an extra few bytes to each output to denote when an output can be spent (block number/time). If not provided, it can be assumed to be 0.


texts: What does "P2P peers available. Skipped DNS seeding" means?

texts:
I'm trying to avoid bitcoin daemon trying to connect to other addresses but the ones that I set in bitcoin.conf.

I've commented vSeeds in chainparams.cpp and I've cleared vFixedSeeds in this way:

        vFixedSeeds = std::vector<SeedSpec6>(pnSeed6_main, pnSeed6_main + ARRAYLEN(pnSeed6_main));
        vFixedSeeds.clear();

But the daemon still tries to connect with some addresses. What I am missing?

What I need to do is to connect two bitcoin daemons that are running in the same machine, with a different genesis block than the main blockchain (both daemons share the same genesis block).


texts: Why don't most Bitcoin exchanges like Mt. Gox accept debit cards?

texts:
The Mt. Gox FAQ reads:

  Unfortunately we do not accept any credit or debit payment

Why is this so? It seems like the most natural way to buy bitcoin would be to pay for it using money in my bank account. However this very method seems to be avoided almost everywhere.


texts: How was the magic network ID value chosen?

texts: Messages on the Bitcoin network are identified by the magic value 0xD9B4BEF9, and on the testnet by 0xDAB5BFFA. Why were these values chosen?


texts: Setting the fee rate on regtest, or, quickly generating full blocks

texts:
I'm setting up some automated testing for a lightning wallet. At the heart of my tests is a bitcoind instance running in regtest mode. I need to be able to set the fee rate - both the fee rate reported by estimatesmartfee and the fee rate which transactions need to match in order to get confirmed.
So far, the only way I can see to do this is to mine lots of blocks filled with transactions that have the desired fee rate. I'm doing this by calling sendtoaddress (via bitcoin-cli) repeatedly in a loop to send small amounts of money into the void. This is painfully slow - it involves generating ~2500 transactions before bitcoind catches the drift that this should be the new reported fee rate. And I have to do this for every test, sometimes multiple times per test, so my CI is taking forever.
I'm wondering if there's any way to avoid doing this. Is there some way to override bitcoind's estimated fee rate and have it refuse to include transactions which pay less than that fee rate when mining blocks? If not, are there any quicker ways to pad out blocks with transactions than what I'm doing?


texts:
What is Sentinel Chain? Is it a cryptocurrency scam?
Can somebody help me? Thx!!!


texts: Test vectors for bitcoin core (blocks and transactions) needed

texts:
I am looking for test vectors to test edge cases of an implementation. For instance:

"Unusual" blocks that made it to the blockchain
Non standard transactions that made it to the blockchain

Anything else that will help in testing the implementation. I have already obtained test vectors for secp256k1, so those are not needed. (If anyone needs them please comment below).


texts: Sending bitcoins programatically without running a node

texts:
How can I send bitcoins in my web app without running the daemon on my server?
Is there a way to do it? Do third parties allow you to send through them?


texts:
What's the recommended way to start testing the Bitcoin Core source code.

Thanks in advance,
Jim


texts: How to get difficulty from Fairbrix/Tenebrix?

texts:
How can I get the difficulty of Fairbrix or Tenebrix directly from the client? Without using an external site.

I use "getinfo" with Bitcoin but with Fairbrix/Tenebrix, "getinfo" doesn't return anything.
I'm running it with their somewhat unstable "portable launcher".

Thanks!


texts: 1,500% transaction fee and 3,5 months to confirm?

texts:
So my service is skimming a tiny 0,001% (1/1,000) fee off every payment that gets through it. Most of the transactions are actually micro-payments so there are thousands of tiny unspent outputs accumulating in the service's wallet. I'm worried now that I will not be able to spent these outputs without having to pay a load of transaction fees and wait for eternity for this payment to clear.

The average btc value of my unspent outputs that come out of the commissions is 100 satoshis (0,000001 btc). That means that if I want to cash out 100 btc, I need to spend on average 100,000,000 of these outputs.

According to: How to calculate transaction size before sending the transaction size is: in*148 + out*34 + 10 plus or minus 'in', which makes my withdrawal equal to: 100,000,000*148 + 2*34 + 10 + 100,000,000 = 14,900,000,078 bytes = 14,9 GB ?! (am I missing something here?)

The maximum block size is 1 MB so I will need to split this transaction in more than 14,900 transactions of 1,000 kB each ?!

A transaction fee of 0.0001 btc per kB is required, so I will need to spend 0,0001 * 1,000 =  0,1 btc for each of these 14,900 transactions which means I will need at least 1,490 btc (to send 100 btc), which is roughly 15 times the amount I'm trying to send!

All these 14,900 transactions will need to be included on different blocks (since they would exceed the maximum block size otherwise) and since one block is found every 10 minutes on average, I will need to wait 14,900 * 10 minutes = 149,000 minutes = 2,483 hours = 103 days = 3 months and a half ?!

Please tell me I got this all wrong. I've really freaked out.

Edit1: Thanks to Nate Eldredge for pointing out an error in the calculations.


texts: Get invoice amount from payment request - LND REST API

texts:
I'm using the REST API of my LN node to generate and pay invoices. I would like to know how to get the invoice amount/value in sats from the payment request I receive.

I found this : https://api.lightning.community/rest/index.html?javascript#v1-invoice, but I don't know how to get the payment hash.

Thanks in advance


texts: Middlecoin vs Wafflepool vs multipool.us

texts:
Which one actually has a better payoff? As I understand from their websites, their fees are:

Middlecoin  3.88%
Wafflepool  1%
Multipool.us    1.50%

So, clearly Wafflepool's the best, but how are their respective "algorithms"? Are they making the right mining decisions - does somebody have some empirical evidence of that?


texts:
Can somebody explain me why atomic swaps are not flawed in that way:

When I give him/her my secret he/she could decide wheter to make the trade or not. If the price does favor him/her after a certain amount of time he/she will execute the trade if not wait for the timeout. Do I miss something?


texts: How does the "failover" setting in cgminer work?

texts:
I have been messing with a p2pool which I like (no fee) but has latency about every week causing the miner to stop mining altogether. I would like to employ some kind of failover strategy so that the miner will mine somewhere else if unable to connect to this free p2pool, but I would like to be mining on the primary pool as often as possible.

I have tried looking at the multipool settings, but they weren't very informative in terms of what happens when. If I set failover does that mean that it will only connect to the second if it can't connect to the first? If not, is there any way to set up cgminer this way?


texts: Can Multibit be set to use a SOCKS proxy on OSX?

texts: I'd like to route my multibit traffic through TOR, but have been unsuccessful finding out if it's possible. It's certainly not in the GUI settings on OSX.


texts:
Where can I get all historical trades BTC price data?

(There are some similar questions, but I am looking for high-resolution data, while the previous questions asked for lower resolution data, such as daily prices.)


texts: Are there numbers on how many pre-orders (or total GH/s) ButterflyLabs already received?

texts:
The whole Bitcoin world is waiting for ButterflyLabs' entree in the mining scene.

Their promised products are quite revolutionary and so they can cause great fluctuations in the BTC price when they finally arrive.

To know how the Bitcoin network would be affected, it would be very useful and interesting to have an idea on how much hashpower will enter for mining.

Calculations of the profits from their miners with the current difficulty are absurd (like a $ 1,299 miner being paid back in just 4 days) and make no sense.
When making estimates for your profit you need also to consider changes in the difficulty, which are predicted to be enormous when ButterflyLabs' hardware launches.

So, to come to my question, I know that Butterfly Labs is not the most transparent company and that they failed to keep most of their promises. But did they ever mentioned numbers or approximations of how many pre-orders they already received? Or how much hashpower they would account for?


texts: Bitcoind running in vagrant can't import bootstrap.dat from external directory

texts:
I am working on a bitcoin development environment in a box, and I've got the bitcoin reference implementation compiling and running so far in this vagrant environment: https://github.com/tlehman/bitcoin-vagrant

Another feature I would like to add is an optional script in /home/vagrant that can download the bootstrap.dat file to speed up downloading the blockchain. My first stab at this problem was to use transmission-cli to download  https://bitcoin.org/bin/blockchain/bootstrap.dat.torrent, and then copy it to ~/.bitcoin/, and then fire up bitcoind for the first time. This works, but it fills up the virtual machine, and it still takes a long time to get imported. On top of that, a vagrant destroy command would blow away all the blockchain data, which is not desirable, I'd like to decouple the data from the program and it's dependencies.

The way I tried to solve this was to mount ~/.bitcoin/ as /vagrant/data/ (which is mounted to a folder in the host filesystem). The problem I am having is that when I run bitcoind -daemon, I get an error saying

Bitcoin server starting
vagrant@precise64:~$ : Error opening block database.

Do you want to rebuild the block database now?

My first guess was that the ~/.bitcoin/bootstrap.dat file was corrupted, but the SHA256 of the file is d05062052be4dd6fbaeac5f17598e52f7ad545f9f938acefaf7067ecce1d7b5a, which matches the SHA256 in the torrent's readme.

My second guess was that LevelDB needs some filesystem feature that isn't present in VirtualBox's synced directories, but I am not sure what that would be.

What can I do to fix this or work around it?


texts:
I have payed last april 21 and april 25 should be my payment but it took days already here is my transaction id

b5a9cb6a67429ec60c51f3aa197bec67af0003c841890132051f9fea40f71f76

And the same as april 22 and i should get my bitcoin on april 26 transaction id

77fc2aa152a80e0abe382a53d5254f113460a6f17cff95852bd0827a572e01cb

I waited how many days just for bitcoin to go to my wallet but it say bitcoin network i dont why and what happen ?please i need help


texts: Can a transaction have more than one recipient?

texts:
I am quite new to Bitcoin. I have a doubt.

Let's say I, person A, have 1 bitcoin. I want to send 0.5 BTC to person B and 0.5 BTC to person C in a single transaction. Is it possible to do so within one single transaction?

Later on, if Person C sends the same bitcoin to Person B, will it be possible for person B to recognize that the bitcoin which it now received from person B and the one which it already received from person A, originated from the same source?


texts: Sending transactions to mining nodes only?

texts: Instead of propagating transactions across all nodes in the bitcoin network, would it be theoretically better to just send transactions to mining nodes as transactions are only confirmed and 'used' when confirmed inside a block. The other nodes would then be able to confirm and validate these transactions when they learn about the new mined block with the 'confirmed' transactions?


texts: Can new types of transactions be included the current block chain?

texts:
I was putting an answer for this question together when I realised my idea would require a new type of transaction to be invented and included in blocks.

Then I wondered how that could work. There are many mining rigs out there which would have no way of validating my transaction type.

Even if some miners do recognise my transaction and even included it in a winning block, all the other miners would not accept that winning block and instead continue mining on the previous block.

What would happen if we wanted to devlop Bitcoin this way? Would we instead have to establish Bitcoin2 with a new block chain?


texts: How is the current hashing power of the entire network measured in real time?

texts:
Does hash power refers to mining nodes only ?

We don't know how many nodes there are on the Bitcoin network, correct?
How do we count them?

Would we need to know [2] in order to figure out what the actual hashing power of the network is?

What are the units of hashing power?


texts: Using blockchain to publish downloadable software verification codes

texts:
What is the point of comparing sha256 of downloaded file with published on the same website code?

Why can't developers of currencies publish file version and sha256 hash on blockchain as alias or message ?

Why don't other software vendors use blockchain as reliable way to distribute verification codes ?

Software vendors could send sha256 code published on their website for a small fee as a reply transaction to each interested account.

This is one real way to raise wide practical interest in cryptocurrencies and blockchain isn't it ?

How about scanning all downloadable online software and putting all types of hashcodes on blockchain, making it useful not just for coin transfers ?

How about setting up auto-reply account as currency feature where software vendor could put hash code and get some coins for it ?


texts: How to reduce Bitcoin loaded wallet memory?

texts: The server has 2GB of RAM memory. It takes up a lot of memory when I create or load a wallet. When I create about 50 wallets, the server is very slow because the memory is full. Is there a way to reduce the memory of a loaded wallet?


texts:
Two days ago, I sent 2.337 BCH from Kraken to Blockchain.info. I cut and paste a BTC address accidentally, not a BCH one. I had used this wallet address about 45 days prior, and so it should be associated with my own BTC wallet, which I have control over.
 (theoretically).

My question then is, how to I get my BCH out of that BTC wallet address on Blockchain.info? I wrote them days ago, and nothing back yet. Any help would be greatly appreciated.


texts: I accidentally used BTC xpub key to generate HD wallet addresses for BCH, can I recover funds?

texts: I am using Exodus wallet and an eCommerce plugin to accept cryptocurrency payments. To generate the HD wallet addresses I needed to provide an xpub key. I accidentally used the BTC xpub key instead of the BCH xpub key. They are different. Is it possible to recover my funds somehow or are they lost forever?


texts: It seems that a BIP (Bitcoin Improvement Proposal) is very similar to an RFC (Request for Comments). Can anybody confirm this, or describe major differences in the two approaches?


texts:
I am using the BitcoinJ API to create my wallet.
When I create a transaction, I provide the change address to which change should be sent.
For example: let there be 1 bitcoin at address A;
then I create a transaction to send 0.1 bitcoins to address B and the change (0.9 bitcoins) back to address A.

In the BitcoinJ wallet, I see that the change (0.9 bitcoins) is not received back. To try to fix that, I created a custom coin selector to explicitly select unconfirmed transactions which are generated by myself---but still I do not see the change (0.9 bitcoins) in my wallet.

This is the transaction view https://www.biteasy.com/testnet/transactions/db66d5058e5773f353447ffa2174a417867e9aa134113f01359576f5e6f2b4c6

And this is my wallet https://www.biteasy.com/testnet/addresses/mnj3589DHMoCyhxDSvWKubjkUoTenmrGkE.

According to my address on Biteasy, there is a balance of 4BTC,
but my BitcoinJ wallet shows only 0.069BTC

Now my question is: Why can't I send return change to same address it is being sent from?


texts: I have my 12 word passphrase and would like to see the contents of my wallet how do I see this wallet on a new app or site?


texts: Transactions for multiple crypto-currency coins in cold storage without downloading full block-chains

texts:
I've searched on the internet and still unable to understand the usage of cold storage. Actually, I want to buy a few types of low price crypto currency coins and save them in my personal devices or papers. Later I need to send them to some exchanges to sell at higher price. I don't want to rely on online sites/firm meanwhile before exchange. Neither I want to download blockchains of each currency.

So, how can I efficiently save my coins in my personal captivity? If I use offline wallet generator, how In-ward and Out-ward transactions will be carried out?


texts:
I issued this transaction on testnet (for a homework later solved with another script). python-bitcoinlib validates the transaction but when i submit it to blockcypher it gets rejected with error:

{"error": "Error validating transaction: Error running script for input 0 referencing e96a1ae8aaff2920601fdfd8cb12289d77bad2a4d595e2093d9d828107023705 at 0: Script was NOT verified successfully.."}

My first transaction scriptPubKey: (transaction hash: e96a1ae8aaff2920601fdfd8cb12289d77bad2a4d595e2093d9d828107023705)

    [2, j1_public_key, j2_public_key, j3_public_key, 3, OP_CHECKMULTISIGVERIFY,
      1, my_public_key, p2_public_key, 2, OP_CHECKMULTISIG]

And the failed transaction scriptSig is:

[0, my_sig, 0, sig_j1, sig_j2]

and failed transaction hex is:

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


texts: Which full node implementation(s) supports SegWit2x?

texts:
I'm running a full node, because I want to support the Bitcoin network, and because I'm interested in the backend mechanisms in Bitcoin.

Now, SegWit2x is approaching. I believe it's important for Bitcoin to increase the block size, so I would like to somehow support the doubling of the block size. Can I somehow support SegWit2x through my choice of full node software? If I can choose between Bitcoin Core, Bitcoin ABC, Bitcoin XT, and Bitcoin Classic: Are there any feature differences that would make those more or less supportive of the block size doubling?


texts: I’m trying to get all transaction ids in the memory pool as json array. I just finish downloading bitcoin core and do now know where to begin. Any help would be appreciated!!


texts: How much would it cost to execute a 51% attack?

texts: I know that it's commonly said that they're not really in the realm of possibility right now, but how much would it really cost to execute a 51% attack on the network?  And are there any organizations out there who might have a goal in mind for which such an attack would be worth it?


texts:
Please help. Probably I set fee too small and now I wait 10 hours so far and transaction is not confirmed yet.

Is there anybody who can help speed it up ?


texts: How to do tx.addInput without tx_hash if sending from address for the first time?

texts: Iam using the bitcoinjs-lib library and trying to do a transaction. Iam doing the tx.addInput method before building but running into a build issue. I assume an error is thrown if blockchainScripthash_listunspent cannot retrieve the previous tx_hash.


texts: What advantages and disadvantages does Ethereum have over Bitcoin? What can you do with Ethereum that you simply cannot with Bitcoin? What price do you pay for these additional functionalities?


texts:
I'm trying to figure out how I'd submit a block in many alt-coins. I originally found this issue in bbqcoin but have since found it in many others. I have bbqcoin (and others) installed from gihub source on Ubuntu 12.04.4

root@ubuntu-hp:~# bbqcoind help
addmultisigaddress <nrequired> <'["key","key"]'> [account]
backupwallet <destination>
dumpprivkey <bbqcoinaddress>
encryptwallet <passphrase>
getaccount <bbqcoinaddress>
getaccountaddress <account>
getaddressesbyaccount <account>
getbalance [account] [minconf=1]
getblock <hash> [decompositions]
getblockcount
getblockhash <index>
getconnectioncount
getdifficulty
getgenerate
gethashespersec
getinfo
getmemorypool [data]
getmininginfo
getnetworkhashps [blocks]
getnewaddress [account]
getpeerinfo
getrawmempool
getreceivedbyaccount <account> [minconf=1]
getreceivedbyaddress <bbqcoinaddress> [minconf=1]
gettransaction <txid> [decompositions]
getwork [data]
getworkex [data, coinbase]
help [command]
importprivkey <bbqcoinprivkey> [label]
keypoolrefill
listaccounts [minconf=1]
listreceivedbyaccount [minconf=1] [includeempty=false]
listreceivedbyaddress [minconf=1] [includeempty=false]
listsinceblock [blockhash] [target-confirmations]
listtransactions [account] [count=10] [from=0]
move <fromaccount> <toaccount> <amount> [minconf=1] [comment]
sendfrom <fromaccount> <tobbqcoinaddress> <amount> [minconf=1] [comment] [comment-to]
sendmany <fromaccount> {address:amount,...} [minconf=1] [comment]
sendrawtx <hex string>
sendtoaddress <bbqcoinaddress> <amount> [comment] [comment-to]
setaccount <bbqcoinaddress> <account>
setgenerate <generate> [genproclimit]
setmininput <amount>
settxfee <amount>
signmessage <bbqcoinaddress> <message>
stop
validateaddress <bbqcoinaddress>
verifymessage <bbqcoinaddress> <signature> <message>

Best I can figure, the closest thing would be sendrawtx.. but that can't be right, can it? I'm thinking at this point I should have taken advantage of the checkout feature, but it's hard to tell what version each coin is on.

Edit: I've found that many coins have this issue as described here: https://github.com/Crypto-Expert/stratum-mining/issues/72

So looks like the solution is to build it yourself, there is a hail-mary workaround which might do the trick but is heavily undocumented. I found reference that you can submit a block through getblocktemplate, https://github.com/moopless/stratum-mining-litecoin/issues/48

When trying with some data I go a json parse error.. has anyone used getblocktemplate submit?


texts:
In the recent BIP about Schnorr's standardization, Pieter Wuille presents an algorithm for batch validation. In my understanding the most heavy operation is the multiplication by a scalar: to make batch validation secure we need to multiply each public nonce by a random factor, thus we get back to two multiplications per signature (plus one). I don't understand why there is the speed up presented in the figure at the beginning of the BIP. Could someone help?

Thanks in advance for your answers!


texts: What, if anything, can I do to recover bitcoin that was stolen from my MtGox acct in June, 2013?

texts:
I understand the short answer is "nothing", but I ask because I've had trouble explaining this to a coworker which made me realize I don't really get it myself.

What information can I glean from following the stolen bitcoin on a blockchain explorer?  1GvfmXt2CKP8QJfw93LNcnNV6KghD5ohVA

How useful is the IP address the withdrawal was made from? IP: 75.110.224.12

Do I have any legal recourse when the company in question is bankrupt, in Japan, and the theft occurred almost five years ago?

Thank you.


texts: Why can't altcoins erode Bitcoin's foundation?

texts:
There already are hundreds of altcoins and even more are being created. However, Bitcoin still dwarfs all altcoins in value.

From a technical point of view, Bitcoin was invented 7 years ago and its technology is far from perfect (e.g. forking, speed). Why can't altcoins with improved features beat Bitcoin?


texts: How does a full node decide which outbound peers to have?

texts:
I understand that a full node can have up to 10 outbound connections (8 full relay peers and 2 block-relay-only peers). I wonder how my full node decides which nodes to connect to for outbound. What are the selection criteria does a node use to evaluate if a peer is good?
If I want to connect to a new specific peer (let's say I know the node's owner IRL or something) but I have already reached my outbound capacity, what specific criteria does my node use to decide which outbound peer to drop in order to make room for the new peer?


texts: What is the "zeitgeist attack"? Does it affect all blockchain technologies?

texts: What exactly is this attack? It would be nice to have a good explanation of how it works and which chains can be effected by this. Does it apply to the bitcoin main chain, or only the newer and smaller alternative chains?


texts: Mining profitability sounds too good! Where is the catch? (2017 edition)

texts:
Given the staggering increase in BTC value over the last few months (nearly 600% in 12 months), I am kicking myself for not getting into the game earlier. I've been lurking around this for years but have been too risk-averse to dive in, and I haven't been paying attention lately. Now, looking into matters again, I am bound to ask: Where is the catch?

(This has been asked before, but the information is outdated.)

A cost/income calculation with present-day numbers (Aug'17) tells me that a dedicated mining device would pay for itself in 86 days and would generate in excess of $2500 per year. That sounds like free money!

If this is really true, then why isn't the whole world up in arms about this new gold rush? Or is it true, and most people are just living under a rock?
If this is true, then why not rush out and buy as many miners as I can afford? Or is it wiser to just buy a bunch of coins instead?

I've tried to take into account current values of:

best hash rate (14Th/s)
difficulty (860,221,984,436) as well as the expected increase
block reward (12, halving to 6 expected in the year 2020)
BTC exchange rate (currently 4162 USD per 1 BTC)
purchase cost of miner ($1288)
cost of miner's power consumption.

Using various online calculators (coinish, blockchained) I arrive at 16.35 USD/day or 2597.50 USD/year when taking difficulty and power cost into account. This still sounds like free money; what's the catch?

(edit: Due to a typo my initial calculation was one order of magnitude too high. These values are now corrected.)


texts:
how exactly is the satoshi value in a raw transaction calculated to decimal? Because on blockchain.info, I cannot figure out how they parse the raw transaction from that value to the JSON result. I thought it would be just a hex to decimal parsing, but I cannot get the same results. Neither I understand it in here, how you get to 49.99990000 BTC (from https://developer.bitcoin.org/reference/transactions.html):
Sorry if it's a silly question.


texts: bitcoin core 0.13.1: Inconsistent getbalance result from RPC

texts:
I have a node which is giving inconsistent results from RPC:

$ bitcoin-cli getbalance
0.01647763
$ bitcoin-cli getbalance "*" 1
1.90937153
$ bitcoin-cli getbalance "" 1
1.90937153
$ bitcoin-cli getbalance * 1
0.00000000
$ bitcoin-cli listaccounts
{
  "": 1.90937153
}

Not sure how can I interpret this. Does my wallet have 0, 0.01647763 or 1.90937153? Documentation for getbalance says that if you don't pass any arguments, the defaults are * (all accounts) and 1, but when I specify those arguments, the result is not the same.

What are the real defaults when not specifying arguments to getbalance?