NSA’s lightweight block cipher family designed for resource-constrained environments. Simon64/128 variant uses 64-bit blocks with 128-bit keys and 44 rounds. Optimized for hardware implementation.
| Property | Value |
|---|---|
| Category | Block Ciphers |
| Sub-category | Block Cipher |
| Security status | 🎓 Educational Only |
| Complexity | Not specified |
| Inventor | NSA (National Security Agency) |
| Year | 2013 |
| Origin | 🇺🇸 United States |
| Source | algorithms/block/simon.js |
| Parameter | Supported values |
|---|---|
| Key sizes | 16 bytes (128 bits) |
| Block sizes | 8 bytes (64 bits) |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Reduced-round attacks | Various attacks exist against reduced-round variants (not full 44 rounds) | Use full-round implementation and consider alternatives for high-security applications |
4 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Simon64/128 - Simon and Speck paper Appendix B (byte-serialised)
| Field | Value |
|---|---|
key |
0001020308090a0b1011121318191a1b |
input |
756e64206c696b65 |
expected |
7aa0dfb920fcc844 |
Vector 2 — Simon64/128 - Crypto++ TestVectors #2
| Field | Value |
|---|---|
key |
435ccae27799f6117c08652eb81e0ebe |
input |
ef4a99d6e0d6992c |
expected |
b172958be0f28647 |
Vector 3 — Simon64/128 - Crypto++ TestVectors #3
| Field | Value |
|---|---|
key |
6cce23b05650d41237fc83805a76eddc |
input |
6e27377afc08ecf4 |
expected |
c889752d52f046e5 |
Vector 4 — Simon64/128 - Crypto++ TestVectors #4
| Field | Value |
|---|---|
key |
c2358c444168bad0ab5067fd536885f1 |
input |
547ab26aa85da02d |
expected |
bd99b9583d4c5449 |