FRAST

This is an implementation of the FRAST cipher (proposed in FRAST: TFHE-friendly Cipher Based on Random S-boxes) using TFHE-rs library.

Updates

• 24.11.15. The setup phase of FRAST is optimized by the split FFT (https://eprint.iacr.org/2024/1318)
• 24.08.19. The first version from the FRAST paper (https://eprint.iarc.org/2024/745)

Tests

There are two tests: 'negacyclic_dbr' and 'frast'.

• 'negacyclic_dbr': test for evaluating double blind rotation
• 'frast': test for evaluating the frast cipher

To run each test, run the following command in the frast directory:

cargo test --release --test `test_name`

Benchmarks

There are foure benchmarks: 'bench_gen_pbs', 'bench_setup', 'bench_frast' and 'bench_online'.

• 'bench_gen_pbs': benchmark for generalized PBS
• 'bench_setup': benchmark for the setup phase
• 'bench_frast': benchmark for the frast cipher in the offline phase
• 'bench_online': benchmark for the online phase

To run each benchmark, run the following command in the frast directory:

cargo bench --bench `bench_name`

Error Analysis

The error anlaysis of the frast evaluation is given in err.sage. The failure probability of the FRAST evaluation is given by 2^-80.32.