Hasty Pudding Cipher (HPC-Medium sub-cipher) as shipped in the DarkCrypt Total Commander plugin. Uses Rich Schroeppel’s original 1998 key-stirring (pre-Wagner-fix); the 96-byte key seeds a 256-bit KX expansion while its last 64 bytes act as an 8-word spice/tweak. 128-bit block, 768-bit key.
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Advanced |
| Inventor | Rich Schroeppel (base HPC); DarkCrypt variant by Alexander Myasnikov |
| Year | 2013 |
| Origin | 🇷🇺 Russia |
| Source | algorithms/block/darkcrypt-hpc.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 96 bytes (768 bits) |
| Block sizes | 16 bytes (128 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Non-standard variant | Modified HPC using the original pre-Wagner-fix stirring and a fixed 256-bit key-seed length; unanalyzed and not recommended for real use. | Use AES or another vetted cipher. |
3 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — DarkCrypt Hpc — zero key/plaintext
| Field | Value |
|---|---|
key |
00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 |
input |
00000000000000000000000000000000 |
expected |
e8d77b317b6ea04abfcb67a2ef4879cb |
Vector 2 — DarkCrypt Hpc — incrementing key/plaintext
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f 404142434445464748494a4b4c4d4e4f 505152535455565758595a5b5c5d5e5f |
input |
000102030405060708090a0b0c0d0e0f |
expected |
3d158e9dc45de315e1cef91efd369acc |
Vector 3 — DarkCrypt Hpc — shifted incrementing key/plaintext
| Field | Value |
|---|---|
key |
0102030405060708090a0b0c0d0e0f10 1112131415161718191a1b1c1d1e1f20 2122232425262728292a2b2c2d2e2f30 3132333435363738393a3b3c3d3e3f40 4142434445464748494a4b4c4d4e4f50 5152535455565758595a5b5c5d5e5f60 |
input |
101112131415161718191a1b1c1d1e1f |
expected |
4d686475ede1aff9e60ef040fd5968f2 |