Ralph Merkle’s Khufu cipher with a 544-bit key as implemented in the DarkCrypt Total Commander plugin: 64-bit Feistel block, 8 octets of 8 rounds (64 rounds total), key-dependent S-boxes built via a self-referential bootstrap encryption. Includes a confirmed register-clobber bug in the key schedule’s swap-index computation and reliance on global (not per-call) key-schedule memory.
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Advanced |
| Inventor | Ralph Merkle; DarkCrypt variant by Alexander Myasnikov |
| Year | 1990 |
| Origin | 🇷🇺 Russia |
| Source | algorithms/block/darkcrypt-khufu512.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 68 bytes (544 bits) |
| Block sizes | 8 bytes (64 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Non-standard key schedule with global-state dependency | The DarkCrypt implementation’s key schedule reads global memory left over from prior setup() calls rather than being a pure function of the key; this implementation reproduces that exactly via shared module state. Encryption for a given key can therefore differ depending on prior key-schedule calls in the same process, exactly like the original implementation. | Use AES or another vetted cipher. |
| Differential cryptanalysis (base Khufu) | Textbook Khufu is broken by differential cryptanalysis; this DarkCrypt variant is unanalyzed. | 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 Khufu — zero key/plaintext
| Field | Value |
|---|---|
key |
00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000 |
input |
0000000000000000 |
expected |
8786833be7a2484b |
Vector 2 — DarkCrypt Khufu — incrementing key/plaintext
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f 40414243 |
input |
0001020304050607 |
expected |
6ea8385a3a73a96b |
Vector 3 — DarkCrypt Khufu — shifted incrementing key/plaintext
| Field | Value |
|---|---|
key |
0102030405060708090a0b0c0d0e0f10 1112131415161718191a1b1c1d1e1f20 2122232425262728292a2b2c2d2e2f30 3132333435363738393a3b3c3d3e3f40 41424344 |
input |
1011121314151617 |
expected |
e629f9a0abc6c61b |