Fletcher-32 checksum providing robust error detection for medium-sized data Uses two 16-bit running sums with modulo 65535 for enhanced error detection.
| Property | Value |
|---|---|
| Category | Checksums |
| Sub-category | Simple Checksum |
| Security status | 🎓 Educational Only |
| Complexity | Beginner |
| Inventor | John G. Fletcher |
| Year | 1982 |
| Origin | 🇺🇸 United States |
| Source | algorithms/checksum/fletcher.js |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Not Cryptographically Secure | Use cryptographic hash functions (SHA-256, SHA-3) for security purposes | — |
| Collision Vulnerability | Use for error detection only, not for data integrity in security contexts | — |
5 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Empty string
| Field | Value |
|---|---|
input |
(empty) |
expected |
00000000 |
Vector 2 — Single byte ‘a’
| Field | Value |
|---|---|
input |
61 |
expected |
00610061 |
Vector 3 — String ‘abcde’ - published test vector, odd length so the last word is zero-padded
| Field | Value |
|---|---|
input |
6162636465 |
expected |
f04fc729 |
Vector 4 — String ‘abcdef’ - published test vector, exact multiple of the 16-bit word
| Field | Value |
|---|---|
input |
616263646566 |
expected |
56502d2a |
Vector 5 — String ‘abcdefgh’ - published test vector
| Field | Value |
|---|---|
input |
6162636465666768 |
expected |
ebe19591 |