Questions tagged [development]

This tag should be used for questions related to creation and ongoing work for different existing and future Bitcoin-related projects and source code.

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2
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1answer
211 views

Why are broadcast checkpoints considered bad?

warren, a LiteCoin dev, said of Peercoin: Good Luck Removing PPC's Centralized Checkpoints Regarding PPC... these amount to empty obfuscating defensive excuses. Sure he wants to remove the ...
2
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3answers
294 views

Which altcoins have testnets?

Bitcoin can be run on a public testnet (by using a different port than the real Bitcoin network). This is very useful for development, because you can test software handling Bitcoin without handling ...
5
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2answers
2k views

How to create a SPV client?

What are the steps a SPV client takes in order to sync? Connect to a peer Set bloom filter for wallet addresses Download all block-headers since latest checkpoint Request every block again with ...
0
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1answer
432 views

Programming for/modding bitcoin-qt on Windows

In multiple places I've found methods of modifying or adding to the bitcoin-qt(or other coin wallet) source on ubuntu or osx, but how would I do this on a Windows machine? If possible, I'd like to be ...
1
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2answers
374 views

How can I find out how much bitcoin is in existence with PHP?

I'm running a Bitcoin blog and I'd love to display a ticket of the total amount of Bitcoins in existence. Unfortunately, I'm not sure where I can find a JSON feed for this (now that MTGOX is gone). Is ...
0
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1answer
362 views

Bitcoin Exchange Api [duplicate]

I need an bitcoin exchange api implemented in my website. Basically there will be one way transactions money->bitcoin and it needs to support major credit cards (visa,mastercard) as well as paypal ...
6
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2answers
554 views

Bitcoind Performance for production usage

Lets say we have one instance of bitcoind running on the production server. And our exchange software/application interacts with it using RPC callbacks for: address generation withdrawal ...
1
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2answers
2k views

How do I use Blockchain.info's Receive Payments API with node JS / Express?

Blockchain has great documentation for PHP, but nothing really for node! Does anyone here have any projects,where they used the blockchain.info Receive Payments API, in their node apps, to receive ...
1
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0answers
226 views

When computing a normalized transaction id, when do I finalize the sha256 hash?

I'm trying to compute the normalized transaction ID so that it matches what is on blockchain.into at the following URL http://blockchain.info/q/hashtontxid/ --- normal TX ID here ---- Given that I ...
1
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3answers
207 views

So how would someone steal coins from my site?

Nearly every attack I've ever read about has involved bad website coding in one fashion or another. Like that that attack on the Doge wallet site in December, where they allegedly injected the website,...
0
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1answer
155 views

Can mining puzzles be made socially valuable? [duplicate]

Bitcoin miners work to solve a random puzzle as "proof of work". A huge amount of raw computing power is going into finding the solution to these puzzles, yet the actual solution to the puzzle serves ...
2
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2answers
1k views

What is the correct Base58 encoding for this uncompressed Public Key RipeMD hash with a zeros in bits 31, 32, or 33?

My understanding is that Base58Checked is always 34 bytes long, and isn't going to be less than 34 bytes even if the first or last bytes of the RipeMD are zero. If this statement isn't true, then ...
1
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2answers
694 views

What are the differences between the transaction and block versions? (v1, v2, v3, etc..)

If I run command to fetch a block, I see version 2 is returned: getblock 0000000000000000ae22455f90306f43e8c806585fe2dfc3b0e92ac7b7620bff Output { "hash" : "...
3
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1answer
168 views

Mine valid but nonstandard transactions

Is there a way to configure cgminer to accept valid but nonstandard transactions for mining? If not, where, theoretically, would be a good place to look if I was interested in mining nonstandard ...
3
votes
1answer
161 views

Is there a signature format, or cryptography has *only one* possible S value?

EDIT: This question is not specific to Bitcoin. It's applicable to any other crypto currency that is interested in using a different signature scheme than Bitcoin or the QT reference client. One ...
0
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1answer
109 views

What parts of Bitcoin (litecoin etc) are Little Endian?

As mentioned on this Hardfork Wishlist, many developers want Bitcoin to be entirely Big Endian for consistency and performance reasons. I'm looking for a concise list of all the areas that Bitcoin ...
1
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1answer
356 views

What encoding is “pubkey” from the JSONRPC validateaddress command?

I need to convert a public key into a form suitable for use with BouncyCastle. To do this I open the debugger and write: ListAddressGroupings I then pick an address and write validateaddress ...
2
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1answer
926 views

Need sample compressed and uncompressed Public / Private key pairs for BigInteger

I am testing a different version of BigInteger that has different endian formats and the native implementation likes to add or remove zeros from the final output. Can anyone provide some sample ...
0
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1answer
2k views

How to get difficulty for Bitcoin and other coins

How do I get access to the latest Bitcoin/Altcoin difficulties from the original "source/network"? I want to develop a C#/.NET application that collect this information. I know that there are web ...
2
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3answers
2k views

Would it be theoretically possible to make a Cryptocurrency in a scripting language like PHP, Python, or Ruby?

Just wondering if this is even possible. If so, are there any practical reasons not to?
5
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2answers
1k views

What encoding or format is the private key in Dumpprivkey?

I'm trying to use the results of Dumpprivkey to sign a message outside of the QT client, however I'm either having a problem signing or extracting the real value of the key. What encoding, endian, or ...
1
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0answers
902 views

Cryptocurrency from Scratch?

I remember seeing a question a while back about how to code your own cryptocurrency here: How to fork Bitcoin and build own cryptocurrency Unfortunately, it seems to suffer from a lack of in-depth ...
0
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0answers
31 views

How to add worker through API?

How to add workers through API? https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list I don't see any method to add workers or may be it is there but with some other name?
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2answers
133 views

How is RonPaulCoin different from Bitcoin/Litecoin?

Is RonPaulCoin a clone of Bitcoin/Litecoin or are there differences beyond the specifications such as coin limit and difficulty algorithm?
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0answers
823 views

mining pool with eloipool, fires up port but cannot connect

I am trying to get eloipool up and running in a solo mining configuration using this installation https://bitcointalk.org/index.php?topic=158105.0 eolipool starts up error free but clients cannot ...
1
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2answers
313 views

Does there exist a SPV-client in another language than Java?

The only (active) project I know that implements a full SPV client is BitcoinJ, which is written in Java. Does somebody know if there are any SPV implementations in other languages (like C) too?
0
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1answer
79 views

Profit by programming a Bitcoin service (wallet) in an “only-now” bc adopting country? [closed]

A country where I am from appears to take Bitcoin into an interest right now. I am a senior programmer at one company and have done several projects, but right now I am mostly interested in the ...
-1
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1answer
365 views

Where does the money come from? [duplicate]

Where does the Bitcoin money come from? You know how banks distribute money, how does someone have enough money to distribute bit coins which can be turned into money?
0
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2answers
234 views

What is miner supposed to do when waiting for longpoll

i am coding simple miner. I succesfully implemented Getwork in basic form. Next thing is gonna be Longpolling. If i understand correctly longpoll is just connection that is waiting for next block. So,...
32
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4answers
49k views

How to fork Bitcoin and build own cryptocurrency

Is there any step-by-step tutorial about how to build own cryptocurrency based on Bitcoin code?
4
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1answer
228 views

How do I determine the balance of an address I don't own? (WebAPI or local API)

I have an arbitrary address. How can I get the current balance of the account through a Web API? ... how do I get it for a local API? I'm also interested in all transaction history for that address. ...
8
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8answers
4k views

bitcoin programming book

is there any reference or authoritative resource, or book on bitcoin programming? Bitcoin is dubbed "programmable money" but there is no obvious resource for how to do it aside from trudging through ...
1
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1answer
124 views

Implementation languages of popular exchanges

What programming languages are some of the popular BTC exchanges implemented in? E.g. MtGox, BTC-E, Coinbase, etc. MtGox is releasing their new Midas trading engine, and there does not seem to be much ...
10
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1answer
1k views

Turing completeness of Bitcoin Script

For me, scripts are one of the most interesting features of Bitcoin. They provide possibilities which have no equivalent in classical currencies. However, the wiki states It is purposefully not ...
0
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1answer
766 views

How get address from pk_script?

We have example in the wiki: [...] Output 1: 40 4B 4C 00 00 00 00 00 - 0.05 BTC (5000000) 19 - pk_script is 25 bytes long ...
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2answers
6k views

Creating a bitcoin/litecoin miner with Javascript

I am a web developer and looking for well written technical documents about how bitcoin/litecoin works, what is the workflow, what is the algorithm and how can I write a miner from scratch by using ...
2
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1answer
217 views

What would be the second greatest bottleneck in the mining process? after the hash generation of course.

Lets pretend theres a fantasy world where I can produce an infinite amount of hashes no time at all... What is the next biggest bottleneck for bitcoin mining? Is it the bitcoin client? Is the client ...
6
votes
1answer
145 views

What “Identity Verification” features will be part of the QT client?

When Patrick Murck testified today at the Homeland Security Digital Currency committee, he mentioned that an identity verification feature will be added to the QT client. What is this identity ...
0
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1answer
119 views

Getting started progmatically

Does anyone know of good resources to get started with working with bitcoin? Mostly involving transactions, eg: creating and storing wallets and moving coins from one wallet to another, etc. This will ...
4
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1answer
1k views

Building from source static bitcoind on Ubuntu

I'm trying to build bitcoind from source on Ubuntu 13.04: $ apt-get install libboost-all-dev ccache pkg-config # deps $ git clone https://github.com/bitcoin/bitcoin.git $ cd bitcoin $ ./configure --...
2
votes
1answer
562 views

How do I communicate with the BTC network? [closed]

Some background: I'm looking into making my own miner. Even though there's some documentation out there, I find it hard to do without looking into loads of existing code, and while I do that, I prefer ...
1
vote
1answer
401 views

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

I understand that the public key (Q) can be extracted from a signature (r,s), but I'm having trouble understanding this line: if (!key.Recover(hash, &vchSig[1], (vchSig[0] - 27) & ~4)) The ...
1
vote
1answer
145 views

How to connect to several Bitcoin nodes using Bitcoin

I'm looking for a way to connect to several Bitcoin nodes using Python... I've been looking in different Bitcoin-for-Python libraries, but I haven't found anything :( What should I do?
2
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4answers
1k views

Is it legal to embed a miner in another open source program for benifit of the programmer?

So say I am writing an open source program, or any program really, and I embed a Bitcoin miner in the code, so that when people run my program, they would be earning Bitcoins for me. Would this be ...
0
votes
1answer
55 views

Would it be possible to make Trophys / Achievements from bitcoin experience

One Trophy could be: "First output signed" And many more milestones on the road to the more advanced usages of the network: "First multisign/multispend", "First completed ANYONECANPAY transaction" ...
1
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3answers
1k views

Is there a working Open source implementation of litecoin mining application for Linux without GUI

Is there a working Open source implementation of litecoin mining application for Linux flavours without GUIs (think debian, ubuntu server etc.) I found a couple of implementations by developers but ...
3
votes
1answer
940 views

jsonRPC calling createrawtransaction in PHP

I can't get createrawtransaction to work in PHP using jsonRPC. I found this thread https://bitcointalk.org/index.php?topic=133769.0 from a few months ago describing the process. It won't work however,...
5
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3answers
2k views

How do I find out what the latest protocol version is?

How do I find out what version Protocol specification is describing?
1
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1answer
486 views

Stable bitcoind build with watch-only wallets

I found out that the new major release of bitcoind will contain support for the watch-only wallets: https://github.com/bitcoin/bitcoin/pull/2861. Anybody knows if there is available a binary package ...
2
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0answers
238 views

What limitations are there to creating a Bitcoin client on Google App Engine?

I want to create a Bitcoin client on App Engine with equivalent protocol functionality to bitcoind. With the new Sockets API available in Python and Java I believe this would almost be possible. The ...