> Academic opportunities > PHD positions

Optimized and efficient transciphering with homomorphic encryption

Technological challenge: Cyber security : hardware and sofware (learn more)

Department: Département Systèmes et Circuits Intégrés Numériques (LIST)

Laboratory: Laboratoire pour la Confiance des sYstèmes de calcuL

Start Date: 01-10-2022

Location: Saclay

CEA Code: SL-DRT-22-0327

Contact: aymen.boudguiga@cea.fr

In the context of applications directly using encrypted data (Fully Homomorphic Encryption or FHE), Transciphering allows to workaround the large expansion of the size of FHE encrypted data, thanks to the use of symmetric cryptography. Transciphering is a recryption technique that delegates the effective homomorphic encryption to the cloud. As a result, a client only has to encrypt (once) a symmetric key under a homomorphic encryption system, while his payload data are encrypted using the chosen symmetric encryption algorithm. In this thesis, we will investigate the use of TFHE for the definition of 8bits efficient operators for transciphering with stream-ciphers. In addition, we will improve and extend these operators to define a whole instructions set for an 8bits processor working on encrypted words. Finally, we will specify a new symmetric encryption algorithm suited for transciphering with levelled homomorphic schemes (e.g., BGV/BFV) and batching.

See all positions Download the offer (.zip)

Email Bookmark and Share