Standard NTT E2 block cipher (256-bit key variant), a 12-round Feistel cipher with initial/final modular-multiplication transforms and an s-box/P-function round structure, submitted to the AES competition in 1998. The DarkCrypt Total Commander plugin implements this unmodified (matches NTT’s own published test vector).
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Advanced |
| Inventor | Masayuki Kanda, Shiho Moriai, Kazumaro Aoki, Hiroki Ueda, Youichi Takashima, Kazuo Ohta, Tsutomu Matsumoto (NTT) |
| Year | 1998 |
| Origin | 🇯🇵 Japan |
| Source | algorithms/block/darkcrypt-e2.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 32 bytes (256 bits) |
| Block sizes | 16 bytes (128 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Not selected for AES | E2 was a first-round AES candidate not advanced past round 1; while not broken, it received far less cryptanalytic scrutiny than AES/Rijndael. | Use AES or another vetted, standardized cipher. |
4 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — NIST AES round-1 E2 KAT ecb_vk.txt, KEYSIZE=256, I=1
| Field | Value |
|---|---|
key |
8000000000000000000000000000000000000000000000000000000000000000 |
input |
00000000000000000000000000000000 |
expected |
1afeb356ae10f7bb2c3221223fb6bd8a |
Vector 2 — DarkCrypt E2 — zero key/plaintext (matches NTT spec Appendix A, Case 3)
| Field | Value |
|---|---|
key |
0000000000000000000000000000000000000000000000000000000000000000 |
input |
00000000000000000000000000000000 |
expected |
5002cb8cd878f26fbab9f52e6c96501e |
Vector 3 — DarkCrypt E2 — incrementing key/plaintext
| Field | Value |
|---|---|
key |
000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f |
input |
000102030405060708090a0b0c0d0e0f |
expected |
dff330c9ebbd520262ee310b1feed4dd |
Vector 4 — DarkCrypt E2 — shifted incrementing key/plaintext
| Field | Value |
|---|---|
key |
0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20 |
input |
101112131415161718191a1b1c1d1e1f |
expected |
8ac3a298e0dd7e5e4d5a858c0a213e10 |