LHA/LHarc -lh5- method: LZSS matching over an 8 KiB window feeding two per-block Huffman trees, a 510-symbol literal/length tree whose code lengths travel through a 19-symbol code-length tree, and a slot-based position tree with raw extra bits.
| Property | Value |
|---|---|
| Category | Compression Algorithms |
| Sub-category | Dictionary |
| Security status | Not classified |
| Complexity | Advanced |
| Inventor | Haruyasu Yoshizaki, Haruhiko Okumura |
| Year | 1988 |
| Origin | 🇯🇵 Japan |
| Source | algorithms/compression/lzh.js |
Status: not classified — treat as unverified.
No vulnerabilities are recorded for this implementation.
8 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Empty input - header only
| Field | Value |
|---|---|
input |
(empty) |
expected |
00000000 |
Vector 2 — Single byte ‘A’ - single-symbol trees
| Field | Value |
|---|---|
input |
41 |
expected |
0100000000010000041000 |
Vector 3 — All literals (ABCD)
| Field | Value |
|---|---|
input |
41424344 |
expected |
04000000000428052450b7c006c0 |
Vector 4 — Simple repetition - AAAA
| Field | Value |
|---|---|
input |
41414141 |
expected |
04000000000220043010b6554010 |
Vector 5 — Pattern ABCABC
| Field | Value |
|---|---|
input |
414243414243 |
expected |
06000000000428053010b7951021b0 |
Vector 6 — English text with repeats
| Field | Value |
|---|---|
input |
74686520717569636b2062726f776e20 666f78206a756d7073206f7665722074 6865206c617a7920646f672e20746865 20717569636b2062726f776e20666f78 206a756d7073206f7665722074686520 6c617a7920646f672e20 |
expected |
5a000000002b48aeb0a93e067fd560f5 5200e0018e46079c0012334184289f56 3c8959c3f2b8551af902a9a235f33bce 07c47eb75e18 |
Vector 7 — Long run - 256 bytes of ‘a’
| Field | Value |
|---|---|
input |
61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 61616161616161616161616161616161 |
expected |
00010000000220043fd136c34010 |
Vector 8 — All 256 byte values in order
| Field | Value |
|---|---|
input |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f 404142434445464748494a4b4c4d4e4f 505152535455565758595a5b5c5d5e5f 606162636465666768696a6b6c6d6e6f 707172737475767778797a7b7c7d7e7f 808182838485868788898a8b8c8d8e8f 909192939495969798999a9b9c9d9e9f a0a1a2a3a4a5a6a7a8a9aaabacadaeaf b0b1b2b3b4b5b6b7b8b9babbbcbdbebf c0c1c2c3c4c5c6c7c8c9cacbcccdcecf d0d1d2d3d4d5d6d7d8d9dadbdcdddedf e0e1e2e3e4e5e6e7e8e9eaebecedeeef f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff |
expected |
00010000010002a000000020406080a0 c0e10121416181a1c1e20222426282a2 c2e30323436383a3c3e40424446484a4 c4e50525456585a5c5e60626466686a6 … (266 bytes; the full value is in the source) |