Fletcher-16 checksum used in network protocols and data transmission Uses two 8-bit running sums with modulo 255 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 | — |
3 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Empty string
| Field | Value |
|---|---|
input |
(empty) |
expected |
0000 |
Vector 2 — Single byte ‘a’
Source: Educational test vector
| Field | Value |
|---|---|
input |
61 |
expected |
6161 |
Vector 3 — String ‘abcde’
Source: Educational test vector
| Field | Value |
|---|---|
input |
6162636465 |
expected |
c8f0 |