https://github.com/gdncc/cryptography

Lean 4 programming language and theorem prover cryptography experiments
https://github.com/gdncc/cryptography

cryptography keccak lean4 sha-3

Last synced: about 1 month ago
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Lean 4 programming language and theorem prover cryptography experiments

• Host: GitHub
• URL: https://github.com/gdncc/cryptography
• Owner: gdncc
• License: mit
• Created: 2024-10-21T20:22:06.000Z (2 months ago)
• Default Branch: main
• Last Pushed: 2024-11-24T19:30:26.000Z (about 1 month ago)
• Last Synced: 2024-11-24T20:30:11.338Z (about 1 month ago)
• Topics: cryptography, keccak, lean4, sha-3
• Language: Lean
• Homepage:
• Size: 4.6 MB
• Stars: 9
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Cryptography

Lean 4 programming language and theorem prover cryptography experiments

> [!CAUTION]

> :warning: **Under no circumstances should this be used for cryptographic

applications.** :warning:

> 

> This is an educational resource. The intended use of this project

> is for learning and experimenting with cryptography using Lean 4.

## SHA-3 Hash Functions

For now, the repository contains the implementation of four cryptographic hash

functions, SHA3-224, SHA3-256, SHA3-384, and SHA3-512, and two extendable-output

functions (XOFs), SHAKE128 and SHAKE256 of the SHA-3 family of functions in pure

Lean 4. It provides one-shot, and streaming APIs.

The library makes use of many Lean 4 features, including dependent typing, type

classes, and proofs.

File [example.lean](Cryptography/Hashes/SHA3/example.lean) shows sample usage of

the API. Build and run:

`lake build Cryptography.Hashes.SHA3.example && ./.lake/build/bin/Cryptography-Hashes-SHA3-example`

The implementation passes the test vectors from

[NIST](https://csrc.nist.gov/projects/cryptographic-algorithm-validation-program/secure-hashing). The

test output must be reviewed manually:

`lake build Cryptography.Hashes.SHA3.test && ./.lake/build/bin/Cryptography-Hashes-SHA3-test`

Some performance testing code is included. Loops cannot be unrolled for now, if

one cares about proving some code properties, because of an

[issue](https://github.com/leanprover/lean4/issues/5324) with Lean's elaborator.

`lake build Cryptography.Hashes.SHA3.perftest && ./.lake/build/bin/Cryptography-Hashes-SHA3-perftest`

All array accesses are formally proven to be within bounds. 

See paper [Cryptography Experiments In Lean 4: SHA-3 Implementation](https://eprint.iacr.org/2024/1880).