Double-IDEA block cipher from the DarkCrypt Total Commander plugin: two consecutive 8-round IDEA passes over a 64-bit block using multiplication mod 65537. The 256-bit key is split into two 128-bit halves, each driving its own IDEA key schedule.
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Intermediate |
| Inventor | IDEA by Xuejia Lai and James Massey; DarkCrypt variant by Alexander Myasnikov |
| Year | 2013 |
| Origin | 🇷🇺 Russia |
| Source | algorithms/block/darkcrypt-twopes.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 32 bytes (256 bits) |
| Block sizes | 8 bytes (64 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Non-standard variant | Undocumented double-IDEA construction with a custom key schedule and subkey whitening constant; 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 Twopes — zero key/plaintext
| Field | Value |
|---|---|
key |
0000000000000000000000000000000000000000000000000000000000000000 |
input |
0000000000000000 |
expected |
e4118731984818f7 |
Vector 2 — DarkCrypt Twopes — incrementing key/plaintext
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f |
input |
0001020304050607 |
expected |
94098860114ea1fd |
Vector 3 — DarkCrypt Twopes — shifted incrementing key/plaintext
| Field | Value |
|---|---|
key |
0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20 |
input |
1011121314151617 |
expected |
8ae166fe3a8d91b2 |