Standard International Data Encryption Algorithm (Lai/Massey) as implemented in the DarkCrypt Total Commander plugin: textbook 8.5-round Lai-Massey structure, big-endian 16-bit words. 64-bit block, 128-bit key. Validated against the DarkCrypt implementation and the classic published IDEA test vector.
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Intermediate |
| Inventor | Xuejia Lai, James L. Massey |
| Year | 1991 |
| Origin | 🇨🇭 Switzerland |
| Source | algorithms/block/darkcrypt-idea.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 16 bytes (128 bits) |
| Block sizes | 8 bytes (64 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Weak keys | IDEA has a small class of weak keys detectable in known-plaintext scenarios. | Use AES or another vetted cipher. |
4 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Published IDEA known-answer test (Botan idea.vec, first vector)
| Field | Value |
|---|---|
key |
ed1bcc9e9267925f3132ba3a8cf9b764 |
input |
7409000000000000 |
expected |
e18315c171b83765 |
Vector 2 — DarkCrypt Idea — zero key/plaintext
| Field | Value |
|---|---|
key |
00000000000000000000000000000000 |
input |
0000000000000000 |
expected |
0001000100000000 |
Vector 3 — DarkCrypt Idea — incrementing key/plaintext
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f |
input |
0001020304050607 |
expected |
864c9d7d208a0e65 |
Vector 4 — DarkCrypt Idea — shifted incrementing key/plaintext
| Field | Value |
|---|---|
key |
0102030405060708090a0b0c0d0e0f10 |
input |
1011121314151617 |
expected |
f9698f89bb4969fe |