BitCrack

A tool for brute-forcing Bitcoin private keys. The main purpose of this project is to contribute to the effort of solving the Bitcoin puzzle transaction: A transaction with 32 addresses that become increasingly difficult to crack.

Using BitCrack

Usage

Use cuBitCrack.exe for CUDA devices and clBitCrack.exe for OpenCL devices.

Note: clBitCrack.exe is still EXPERIMENTAL, as users have reported critial bugs when running on some AMD and Intel devices.

Note for Intel users:

There is bug in Intel's OpenCL implementation which affects BitCrack. Details here: #123

xxBitCrack.exe [OPTIONS] [TARGETS]

Where [TARGETS] are one or more Bitcoin address

Options:

-i, --in FILE
    Read addresses from FILE, one address per line. If FILE is "-" then stdin is read

-o, --out FILE
    Append private keys to FILE, one per line

-d, --device N
    Use device with ID equal to N

-b, --blocks BLOCKS
    The number of CUDA blocks

-t, --threads THREADS
    Threads per block

-p, --points NUMBER
    Each thread will process NUMBER keys at a time

--keyspace KEYSPACE
    Specify the range of keys to search, where KEYSPACE is in the format,

	START:END start at key START, end at key END
	START:+COUNT start at key START and end at key START + COUNT
    :END start at key 1 and end at key END
	:+COUNT start at key 1 and end at key 1 + COUNT

-c, --compressed
    Search for compressed keys (default). Can be used with -u to also search uncompressed keys

-u, --uncompressed
    Search for uncompressed keys, can be used with -c to search compressed keys

--compression MODE
    Specify the compression mode, where MODE is 'compressed' or 'uncompressed' or 'both'

--list-devices
    List available devices

--stride NUMBER
    Increment by NUMBER

--share M/N
    Divide the keyspace into N equal sized shares, process the Mth share

--continue FILE
    Save/load progress from FILE

Examples

The simplest usage, the keyspace will begin at 0, and the CUDA parameters will be chosen automatically

xxBitCrack.exe 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH

Multiple keys can be searched at once with minimal impact to performance. Provide the keys on the command line, or in a file with one address per line

xxBitCrack.exe 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH 15JhYXn6Mx3oF4Y7PcTAv2wVVAuCFFQNiP 19EEC52krRUK1RkUAEZmQdjTyHT7Gp1TYT

To start the search at a specific private key, use the --keyspace option:

xxBitCrack.exe --keyspace 766519C977831678F0000000000 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH

The --keyspace option can also be used to search a specific range:

xxBitCrack.exe --keyspace 80000000:ffffffff 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH

To periodically save progress, the --continue option can be used. This is useful for recovering after an unexpected interruption:

xxBitCrack.exe --keyspace 80000000:ffffffff 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
...
GeForce GT 640   224/1024MB | 1 target 10.33 MKey/s (1,244,659,712 total) [00:01:58]
^C
xxBitCrack.exe --keyspace 80000000:ffffffff 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
...
GeForce GT 640   224/1024MB | 1 target 10.33 MKey/s (1,357,905,920 total) [00:02:12]

Use the -b, -t and -p options to specify the number of blocks, threads per block, and keys per thread.

xxBitCrack.exe -b 32 -t 256 -p 16 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH

Choosing the right parameters for your device

GPUs have many cores. Work for the cores is divided into blocks. Each block contains threads.

There are 3 parameters that affect performance: blocks, threads per block, and keys per thread.

blocks: Should be a multiple of the number of compute units on the device. The default is 32.

threads: The number of threads in a block. This must be a multiple of 32. The default is 256.

Keys per thread: The number of keys each thread will process. The performance (keys per second) increases asymptotically with this value. The default is256. Increasing this value will cause the kernel to run longer, but more keys will be processed.

Build dependencies

Visual Studio 2019 (if on Windows)

For CUDA: CUDA Toolkit 10.1

For OpenCL: An OpenCL SDK (The CUDA toolkit contains an OpenCL SDK).

Building in Windows

Open the Visual Studio solution.

Build the clKeyFinder project for an OpenCL build.

Build the cuKeyFinder project for a CUDA build.

Note: By default the NVIDIA OpenCL headers are used. You can set the header and library path for OpenCL in the BitCrack.props property sheet.

Building in Linux

Using make:

Build CUDA:

make BUILD_CUDA=1

Build OpenCL:

make BUILD_OPENCL=1

Or build both:

make BUILD_CUDA=1 BUILD_OPENCL=1

Supporting this project

If you find this project useful and would like to support it, consider making a donation. Your support is greatly appreciated!

BTC: 1LqJ9cHPKxPXDRia4tteTJdLXnisnfHsof

LTC: LfwqkJY7YDYQWqgR26cg2T1F38YyojD67J

ETH: 0xd28082CD48E1B279425346E8f6C651C45A9023c5

Contact

Send any questions or comments to [email protected]