Hawkynt

RZIP

Long-range redundancy-elimination compressor that indexes the entire input with a rolling hash so LZ77-style (offset,length) matches can be found at arbitrary distances, far beyond a classic 32K/64K sliding window. Literal bytes are entropy-coded with a self-contained order-0 canonical Huffman stage.

Properties

Property	Value
Category	Compression Algorithms
Sub-category	Long-Range
Security status	Not classified
Complexity	Advanced
Inventor	Andrew Tridgell
Year	1998
Origin	🇦🇺 Australia
Source	algorithms/compression/rzip.js

Security

Status: not classified — treat as unverified.

No vulnerabilities are recorded for this implementation.

Documentation

• rzip - a large-file compression program (project home)
• Andrew Tridgell, “Efficient Algorithms for Sorting and Synchronization” (PhD thesis, ANU, 1999)
• rzip(1) manual page

References

• Rzip - Wikipedia
• lrzip - Long Range ZIP (rzip descendant)

Test vectors

7 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.

Vector 1 — RZIP round-trip - empty input

Field	Value
input	(empty)
expected	(empty)

Vector 2 — RZIP round-trip - single byte

Field	Value
input	41
expected	(empty)

Vector 3 — RZIP round-trip - long repetitive run (2000 bytes)

Field	Value
input	42424242424242424242424242424242 42424242424242424242424242424242 42424242424242424242424242424242 42424242424242424242424242424242 … (2000 bytes; the full value is in the source)
expected	(empty)

Vector 4 — RZIP round-trip - alternating byte pattern

Field	Value
input	58595859585958595859585958595859 58595859585958595859585958595859 58595859585958595859585958595859 58595859585958595859585958595859 … (600 bytes; the full value is in the source)
expected	(empty)

Vector 5 — RZIP round-trip - pseudo-random binary sample

Field	Value
input	05048ba2e81c7e8c98c80abef712b375 65f567f3fea96c7f496cac2716da4f01 764a92f603c74d52f48baaa89f29edc4 75b954b693c2713474ab85df64ecbe24 … (500 bytes; the full value is in the source)
expected	(empty)

Vector 6 — RZIP round-trip - identical blocks separated by 40KB of filler (long-range match, exceeds a 32K/64K sliding window)

Field	Value
input	525a49502d4c4f4e472d52414e47452d 4d41524b45522d424c4f434b2d303132 3334353637383941424344454610df9e 68ab5bc80b2f78ef4420b08ebf3fb252 … (40090 bytes; the full value is in the source)
expected	(empty)

Vector 7 — RZIP round-trip - spec-flavoured description text

Field	Value
input	525a49502066696e6473206c6f6e6720 64697374616e636520726564756e6461 6e637920696e207468652077686f6c65 2066696c65207573696e67206120726f 6c6c696e672068617368206469637469 6f6e6172792c207468656e2072656c69 6573206f6e2061207365636f6e642073 7461676520636f6d70726573736f7220 666f7220656e74726f707920636f6469 6e67206f6620746865206c6974657261 6c20646174612e
expected	(empty)

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