A high-performance GPU-accelerated solver for the Incapsula proof-of-work SHA-1 algorithm. This tool leverages NVIDIA CUDA to brute-force nonces in parallel, dramatically reducing solve times compared to a CPU implementation.

When accessing certain protected resources, Incapsula issues a proof-of-work challenge: a client must find a nonce that, when combined with a salt and fed into the SHA-1 algorithm, matches a server-provided target hash within a time limit. This solver:

• Reads the time limit (T), target hash (D), and salt (S) from script challenge data.
• Launches thousands of CUDA threads to test nonces in parallel.
• Uses constant memory and unrolled loops for maximum throughput.
• Reports the first valid nonce (if found) and timing statistics.

The reese84 script contains PoW information which is encoded as base64. Example:

eyJjIjoie1widFwiOjE2Nzc3MjE1LFwiZFwiOlwiNDk3Zjg4MTM3NTE5MDc4ZTZhY2U3MTk3NzA5N2M3ZDg5ZWY1NGYyZVwiLFwic1wiOlwiNDllYWZhZTE1ODQ0NGFmNjkxMzUyN2Y5Yzk5N2U3NjhcIn0iLCJzIjoiY1BPL2tONmtYeGFVQWlUSkpRbmJCMTdSR1Jsc2JSemI3WTJmUkkxWTdNR3M4NXJZOTgrNHZVeGdZc01OZ1YrVVRDUmhGMHFPNlRWRjg5OTU1aExqckE2Wk96TFNaVUNGZDJNNUlHSHBBMWdNYmJiYzduNVN2bkFzSWNuRnlVcXRpa3J5Z3ZVRnppZ1pRR1l6In0=

Decoding it we get:

{
  "c": "{\"t\":16777215,\"d\":\"497f88137519078e6ace71977097c7d89ef54f2e\",\"s\":\"49eafae158444af6913527f9c997e768\"}",
  "s": "cPO/kN6kXxaUAiTJJQnbB17RGRlsbRzb7Y2fRI1Y7MGs85rY98+4vUxgYsMNgV+UTCRhF0qO6TVF89955hLjrA6ZOzLSZUCFd2M5IGHpA1gMbbbc7n5SvnAsIcnFyUqtikrygvUFzigZQGYz"
}

1. Parse the inner c string as JSON.

2. Read the properties:

   • t: time limit in milliseconds
   • d: target hash (20-byte SHA-1) in hex
   • s: salt (16 bytes) in hex

For the example above, you would use:

T = 16777215                                  # max execution time in milliseconds
D = 497f88137519078e6ace71977097c7d89ef54f2e  # 20-byte SHA-1 target
S = 49eafae158444af6913527f9c997e768          # 16-byte salt

• Windows 10 or later
• NVIDIA GPU with compute capability 5.0 or higher
• CUDA Toolkit 10.0+
• A C++11-compatible compiler (Visual Studio 2017+ recommended)

1. Open a "x64 Native Tools Command Prompt for VS".

2. Navigate to the project root (where pow_solver.cu resides).

3. Compile with:

   nvcc -O3 -std=c++11 -o pow_solver.exe pow_solver.cu

4. Ensure pow_solver.exe was created successfully.

pow_solver.exe <T_ms> <D_hex20> <S_hex16>

• <T_ms>: time limit (ms)
• <D_hex20>: 20-byte target hash in hex
• <S_hex16>: 16-byte salt in hex

pow_solver.exe 16777215 497f88137519078e6ace71977097c7d89ef54f2e 49eafae158444af6913527f9c997e768

Output will look like:

foundNonce: 12345678
iterations: 1048576
timeTaken: 36 ms

If no nonce is found within the time limit, you’ll see:

No valid nonce found in 1048576 iterations within 16777215 ms

Note:: CPU benchmark was run single-threaded

Speedup: ≈583× faster on the GPU than on the CPU.

This project is licensed under the MIT License. See LICENSE for details.