Bootstrapping BGV Ciphertexts with a Wider Choice of $$p$$ and $$q$$

Autor: Nigel P. Smart, Joop van de Pol, Emmanuela Orsini
Rok vydání: 2015
Předmět:
Zdroj: Lecture Notes in Computer Science ISBN: 9783662464465
Public Key Cryptography
DOI: 10.1007/978-3-662-46447-2_30
Popis: We describe a method to bootstrap a packed BGV ciphertext which does not depend (as much) on any special properties of the plaintext and ciphertext moduli. Prior “efficient” methods such as that of Gentry et al. (PKC 2012) required a ciphertext modulus \(q\) which was close to a power of the plaintext modulus \(p\). This enables our method to be applied in a larger number of situations. Also unlike previous methods our depth grows only as \(O(\log p + \log \log q)\) as opposed to the \(\log q\) of previous methods. Our basic bootstrapping technique makes use of a representation of the group \({\mathbb {Z}}_q^+\) over the finite field \({\mathbb {F}}_p\) (either based on polynomials or elliptic curves), followed by polynomial interpolation of the reduction mod \(p\) map over the coefficients of the algebraic group.
Databáze: OpenAIRE