Ancient Hebrew substitution cipher that reverses the alphabet. Maps each letter to its opposite position (A↔Z, B↔Y, etc.). Simple monoalphabetic substitution cipher with fixed key that is its own inverse.
| Property | Value |
|---|---|
| Category | Encoding Schemes |
| Sub-category | Text Encoding |
| Security status | 🎓 Educational Only |
| Complexity | Beginner |
| Inventor | Ancient Hebrew scholars |
| Year | -500 |
| Origin | 🇮🇱 Israel |
| Source | algorithms/encoding/atbash.js |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Frequency Analysis | Simple substitution cipher vulnerable to frequency analysis - letter frequencies preserved | Educational use only - easily broken by frequency analysis |
| Pattern Recognition | Fixed transformation pattern makes it vulnerable to pattern recognition attacks | Combine with other techniques or use for educational purposes only |
3 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Basic Atbash transformation
| Field | Value |
|---|---|
key |
(empty) |
input |
48454c4c4f |
expected |
53564f4f4c |
Vector 2 — Full alphabet test
| Field | Value |
|---|---|
key |
(empty) |
input |
4142434445464748494a4b4c4d4e4f505152535455565758595a |
expected |
5a595857565554535251504f4e4d4c4b4a494847464544434241 |
Vector 3 — Mixed case preservation
| Field | Value |
|---|---|
key |
(empty) |
input |
48656c6c6f20576f726c64 |
expected |
53766f6f6c20446c696f77 |