fhegen

This is a parameter generator for the leveled BGV and BFV scheme, joint work by the Crypto Research Center at the Technology Innovation Institute and the Chair of Security Engineering at Ruhr University Bochum.

Usage

Interactive Mode: python src/interactive.py

Feel free to browse the source code or open an issue if you encounter any problems with the generator.

Output

Generated your BGV configuration!
model: Base
sec:   137
d:     4096
t:     65537
logq:  65 (31, 30, 4)
logP:  36

The output provides multiple values: the chosen model 'model', the estimated security sec, the polynomial degree d, the plaintext modulus t and the size of the ciphertext modulus qbits including the sizes for the top and bottom modulus as well as the middle moduli (see below). In addition, we output the size of the key switching modulus Pbits.

The top modulus is the first modulus in the prime chain, that is the modulus to be switched down from directly after encryption, and the bottom modulus is the modulus that is left before decrypting. The middle moduli are the other moduli in the middle.

Note that due to some discrepancies with library internals, some parameter sets might not work as expected. If you encounter such a parameter set or have any other questions, open an issue or send an email to johannes.mono (at) rub.de.

Cite

The accompanying paper is available on ePrint. For citations, please use the snippet below.

@misc{cryptoeprint:2022/706,
      author = {Johannes Mono and Chiara Marcolla and Georg Land and Tim Güneysu and Najwa Aaraj},
      title = {Finding and Evaluating Parameters for {BGV}},
      howpublished = {Cryptology ePrint Archive, Paper 2022/706},
      year = {2022},
      note = {\url{https://eprint.iacr.org/2022/706}},
      url = {https://eprint.iacr.org/2022/706}
}