Leviathan (DarkCrypt)
Keystream-driven block cipher from the DarkCrypt Total Commander plugin: a four-round doubled RC4-style table schedule feeds a Fibonacci-style position counter with S-box-diffused output words, XORed with the block. Exposed through the plugin’s generic stream setup()/crypt() interface but only ever advances one 16-byte block per call.
Properties
| Property |
Value |
| Category |
Block Ciphers |
| Sub-category |
Block Cipher |
| Security status |
🎓 Educational Only |
| Complexity |
Intermediate |
| Inventor |
Leviathan stream cipher by David McGrew and Scott Fluhrer; DarkCrypt variant by Alexander Myasnikov |
| Year |
2013 |
| Origin |
🇷🇺 Russia |
| Source |
algorithms/block/darkcrypt-leviathan.js |
Parameters
| Parameter |
Supported values |
| Key sizes |
16 bytes (128 bits) |
| Block sizes |
16 bytes (128 bits) |
Security
Status: 🎓 Educational Only
Known vulnerabilities
| Issue |
Description |
Mitigation |
| Non-standard exposure |
Exposed as a single-block primitive via a stream-cipher interface that discards the requested length; the underlying keystream generator is unanalyzed as reconstructed here and not recommended for real use. |
Use a vetted stream or block cipher. |
Documentation
Test vectors
3 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — DarkCrypt Leviathan — zero block, incrementing key
| Field |
Value |
key |
000102030405060708090a0b0c0d0e0f |
input |
00000000000000000000000000000000 |
expected |
3d2a20bbae89b73ffc9e78598186ef31 |
Vector 2 — DarkCrypt Leviathan — mixed key, non-zero block (verified against the DarkCrypt implementation)
| Field |
Value |
key |
0f1e2d3c4b5a69788796a5b4c3d2e1f0 |
input |
00112233445566778899aabbccddeeff |
expected |
fd76bbdecbf577ca8cc541067323f9e7 |
Vector 3 — DarkCrypt Leviathan — all-0xFF key, two incrementing blocks continue the keystream (verified against the DarkCrypt implementation)
| Field |
Value |
key |
ffffffffffffffffffffffffffffffff |
input |
000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f |
expected |
b4a2c6b7ffce411e2e2aa6b5015d2ac03cb79098609bda1896aaf3a20cdb7151 |
← All algorithms