On the practical CPAD security of “exact” and threshold FHE schemes and libraries

ePrint Report: On the practical CPAD security of “exact” and threshold FHE schemes and libraries

Marina Checri, Renaud Sirdey, Aymen Boudguiga, Jean-Paul Bultel, Antoine Choffrut

In their 2021 seminal paper, Li and Micciancio presented a passive attack against the CKKS approximate FHE scheme and introduced the notion of CPAD security. The current status quo is that this line of attacks does not apply to ``exact'' FHE. In this paper, we challenge this statu quo by exhibiting a CPAD key recovery …

attack eprint report fhe libraries notion passive paul report security threshold