TFHE ciphertext

FHE Questions
1

Any reason why p and q are powers of 2 and not primes in TFHE scheme?

2

Please provide additional context and details related to your question. This is important since different research papers and academic sources often employ unique notations. Specifically, TFHE utilizes multiple moduli, so it would be helpful if you could:

  • Specify the full name of the parameter you’re inquiring about
  • Provide relevant definitions or formulas
  • Share a link (and page number) to the specific resource or paper you’re referencing
3

For plaintext modulus p, the motivation it to support large-precision operations, such as large-precision sign evaluation (see Large-Precision Homomorphic Sign Evaluation using FHEW/TFHE Bootstrapping for more information).

For ciphertext modulus q, we need a power of two since power-of-two cyclotomic rings are used internally (in Ring-GSW) to do the bootstrapping.