Lempel-Ziv-Storer-Szymanski compression algorithm. An improved variant of LZ77 that omits short matches and uses bit flags to distinguish literals from references. Wire format: a 4-byte little-endian original-length header, then groups of up to 8 tokens each preceded by a flag byte (bit=1 literal, bit=0 match); matches are 2 bytes encoding a 12-bit distance and 4-bit length (3-18) found via a 3-byte hash-chain match finder.
| Property | Value |
|---|---|
| Category | Compression Algorithms |
| Sub-category | Dictionary-based |
| Security status | Not classified |
| Complexity | Intermediate |
| Inventor | James A. Storer and Thomas G. Szymanski |
| Year | 1982 |
| Origin | 🇺🇸 United States |
| Source | algorithms/compression/lzss.js |
Status: not classified — treat as unverified.
No vulnerabilities are recorded for this implementation.
6 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — AAAAAAAAAA repetition
| Field | Value |
|---|---|
input |
41414141414141414141 |
expected |
0a00000001410006 |
Vector 2 — Random data - no matches
| Field | Value |
|---|---|
input |
4142434445464748494a4b4c4d4e4f50 |
expected |
10000000ff4142434445464748ff494a4b4c4d4e4f50 |
Vector 3 — Empty input
| Field | Value |
|---|---|
input |
(empty) |
expected |
00000000 |
Vector 4 — Highly repetitive data - 300 bytes
| Field | Value |
|---|---|
input |
58585858585858585858585858585858 58585858585858585858585858585858 58585858585858585858585858585858 58585858585858585858585858585858 … (300 bytes; the full value is in the source) |
expected |
2c0100000158000f000f000f000f000f 000f000f00000f000f000f000f000f00 0f000f000f00000f0008 |
Vector 5 — Alternating pattern - 300 bytes
| Field | Value |
|---|---|
input |
5a595a595a595a595a595a595a595a59 5a595a595a595a595a595a595a595a59 5a595a595a595a595a595a595a595a59 5a595a595a595a595a595a595a595a59 … (300 bytes; the full value is in the source) |
expected |
2c010000035a59001f001f001f001f00 1f001f00001f001f001f001f001f001f 001f001f00001f001f0017 |
Vector 6 — English text sample - repeated sentence
| Field | Value |
|---|---|
input |
54686520717569636b2062726f776e20 666f78206a756d7073206f7665722074 6865206c617a7920646f672e20546865 20717569636b2062726f776e20666f78 … (450 bytes; the full value is in the source) |
expected |
c2010000ff5468652071756963ff6b20 62726f776e20ff666f78206a756d70ff 73206f7665722074fe01e06c617a7920 646f0f672e205402cf02cf02cf02cf00 02cf02cf02cf02cf02cf02cf02cf02cf 0002cf02cf02cf02cf02cf02cf02cf02 cf0002cf02cf02c5 |