cr-marcstevens/sha1collisiondetection

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

1414 stars · 222 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

A C library and command-line tool that computes SHA-1 hashes while detecting known cryptanalytic collision attacks against SHA-1 with probability 1. It acts as a near drop-in replacement for sha1sum and common SHA-1 libraries, offering a safe-hash mode that protects applications like digital signature verification from collision forgeries.

Use cases

• detect sha-1 collision attacks in files
• drop-in replacement for sha1sum with collision detection
• protect digital signatures against sha-1 collision forgeries
• verify files like the shattered pdf collision
• compute safe sha-1 hashes for colliding files
• scan files for cryptanalytic hash collisions

When to choose

• you must keep using SHA-1 but need protection against known collision attacks
• you want a fast drop-in replacement for sha1sum or existing SHA-1 libraries
• you need to detect forged files created with attacks like SHAttered or Sha-mbles

When to avoid

• you can migrate to SHA-256 or other modern hash functions instead
• you need detection of arbitrary future collision attacks beyond the top 32 disturbance vectors
• you need a general-purpose cryptographic hashing library with many algorithms

Facets

library · maturity stable

cryptography security cli security developer-tools windows cli cpp c sha1 collision-detection hashing counter-cryptanalysis c algorithms linux macos

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