FNAm2 (Feistel Net Algorithm mark 2) as shipped with the DarkCrypt Total Commander plugin. A 128-bit-block / 512-bit-key ARX-with-multiply construction: 64 sequential steps mix the four little-endian words using subkeys built by 32-bit multiplication from the key, the step number and the block’s position in the message.
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Intermediate |
| Inventor | Alexey Kobzin (DarkCrypt implementation by Alexander Myasnikov) |
| Year | 2009 |
| Origin | 🇷🇺 Russia |
| Source | algorithms/block/darkcrypt-fnam2.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 64 bytes (512 bits) |
| Block sizes | 16 bytes (128 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Non-standard cipher | Amateur ARX-with-multiply design without published cryptanalysis; not recommended for real use. | Use AES or another vetted cipher. |
6 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — DarkCrypt Fnam2 — zero key/plaintext
| Field | Value |
|---|---|
key |
00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 |
input |
00000000000000000000000000000000 |
expected |
e7dbfb251bf0fcfb302602cc2cfe03f2 |
Vector 2 — DarkCrypt Fnam2 — incrementing key/plaintext
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f |
input |
000102030405060708090a0b0c0d0e0f |
expected |
838b7b06c845801344698e2fd3b89fc0 |
Vector 3 — DarkCrypt Fnam2 — shifted incrementing key/plaintext
| Field | Value |
|---|---|
key |
0102030405060708090a0b0c0d0e0f10 1112131415161718191a1b1c1d1e1f20 2122232425262728292a2b2c2d2e2f30 3132333435363738393a3b3c3d3e3f40 |
input |
101112131415161718191a1b1c1d1e1f |
expected |
7baf2995776dab041609d53a6b4b59c7 |
Vector 4 — DarkCrypt Fnam2 — four zero blocks (per-block subkeys)
| Field | Value |
|---|---|
key |
00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 |
input |
00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 |
expected |
e7dbfb251bf0fcfb302602cc2cfe03f2 399dfb35a02cc6fa236003b82c1d1121 f9defb1b1c9ee8aa2bc9020a31a91179 6719fd279e078a1acf7102ee2924a03e |
Vector 5 — DarkCrypt Fnam2 — three incrementing blocks, encryption
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f |
input |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f |
expected |
838b7b06c845801344698e2fd3b89fc0 b6aa47fdc0a586afab4fd529ed4071de f30c3a0c501ae7ccbf86f316fd42d5ca |
Vector 6 — DarkCrypt Fnam2 — three incrementing blocks, from the plugin’s decryption
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f |
input |
5deae5e351e0f3a4ab28d570de4af746 905e59febfb0c7f66b7ac4e1ef8f288d a4e89bc3bef249d6e6e580768f26e7d7 |
expected |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f |