Dilithium

A rust implementation of the Dilithium, a KEM standardised by the NIST Post-Quantum Standardization Project.

See the features section for different options regarding security levels and modes of operation. The default security setting is Dilithium3.

It is recommended to use Dilithium in a hybrid system alongside a traditional signature algorithm such as ed25519.

Minimum Supported Rust Version: 1.50.0

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Installation

cargo add pqc_dilithium

Usage

use pqc_dilithium::*;

Key Generation

let keys = Keypair::generate();
assert!(keys.public.len() == PUBLICKEYBYTES);
assert!(keys.expose_secret().len() == SECRETKEYBYTES);

Signing

let msg = "Hello".as_bytes();
let sig = keys.sign(&msg);
assert!(sig.len() == SIGNBYTES);

Verification

let sig_verify = verify(&sig, &msg, &keys.public);
assert!(sig_verify.is_ok());

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AES mode

Dilithium-AES, that uses AES-256 in counter mode instead of SHAKE to expand the matrix and the masking vectors, and to sample the secret polynomials. This offers hardware speedups on certain platforms.

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Randomized signing

One may want to consider randomized signatures in situations where the side channel attacks of [SBB+18, PSS+18] exploiting determinism are applicable. Another situation where one may want to avoid determinism is when the signer does not wish to reveal the message that is being signed. While there is no timing leakage of the secret key, there is timing leakage of the message if the scheme is deterministic. Since the randomness of the scheme is derived from the message, the number of aborts for a particular message will always be the same.

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Features

By default this library uses Dilithium3

Name	Description
mode2	Uses Dilithium2
mode5	Uses Dilithium5
aes	Uses AES256-CTR instead of SHAKE
random_signing	Enables randomized signing of messages
wasm	For compiling to WASM targets

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Testing

To run the known answer tests, you'll need to enable the dilithium_kat in RUSTFLAGS eg.

RUSTFLAGS="--cfg dilithium_kat" cargo test

To run through all possible features use the test_matrix.sh script.

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Benchmarking

This library uses the criterion benchmarking suite. To use you must enable bench eg.

RUSTFLAGS="--cfg bench" cargo bench

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WebAssembly

To compile the wasm files yourself you need to enable the wasm feature.

For example, using wasm-pack:

wasm-pack build -- --features wasm

Which will export the wasm, javascript and typescript files into ./pkg/.

To compile a different variant into a separate folder:

wasm-pack build --out-dir pkg_mode5/ -- --features "wasm mode5" 

There is also a basic html demo in the www folder.

From the www folder run:

npm install
npm run start

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Alternatives

The PQClean project has rust bindings for their C post quantum libraries.

https://github.com/rustpq/pqcrypto/tree/main/pqcrypto-dilithium

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About

Dilithium is a digital signature scheme that is strongly secure under chosen message attacks based on the hardness of lattice problems over module lattices. The security notion means that an adversary having access to a signing oracle cannot produce a signature of a message whose signature he hasn't yet seen, nor produce a different signature of a message that he already saw signed. Dilithium has been standardised by the NIST post-quantum cryptography project.

The official website: https://pq-crystals.org/dilithium/

Authors of the Dilithium Algorithm:

• Roberto Avanzi, ARM Limited (DE)
• Joppe Bos, NXP Semiconductors (BE)
• Léo Ducas, CWI Amsterdam (NL)
• Eike Kiltz, Ruhr University Bochum (DE)
• Tancrède Lepoint, SRI International (US)
• Vadim Lyubashevsky, IBM Research Zurich (CH)
• John M. Schanck, University of Waterloo (CA)
• Peter Schwabe, Radboud University (NL)
• Gregor Seiler, IBM Research Zurich (CH)
• Damien Stehle, ENS Lyon (FR)

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Contributing

Contributions welcome. For pull requests create a feature fork, by submitting PR's you agree for the code to be dual licensed under MIT/Apache 2.0