An overview of Hybrid Homomorphic Encryption

# Abstract:

Fully Homomorphic Encryption (FHE) has long been considered the crown jewel of cryptology and it is only recently that efficient solutions have started to emerge. Being as it is, the current state of the art of FHE still comes along with a huge expansion factor that implies an overload both in computation time and bandwidth usage.

Hybrid Homomorphic Encryption, or transciphering, aims to solve the latter issue by combining the efficiency of light symmetric schemes with the computational power of FHE. In this talk, we will present an history of HHE, talk about the latest advances in the domain and address the issues that are yet to be solved.

# The speakers

Orel Cosseron & Clément Hoffmann

# Important links:

Can Homomorphic Encryption be Practical?
> https://eprint.iacr.org/2011/405.pdf

Ciphers for MPC and FHE1
> https://eprint.iacr.org/2016/687.pdf

Towards Stream Ciphers for Efficient FHE with Low-Noise Ciphertexts
> https://eprint.iacr.org/2016/254.pdf

Stream ciphers: A Practical Solution for Efficient Homomorphic-Ciphertext Compression
> https://eprint.iacr.org/2015/113.pdf

Rasta: A cipher with low ANDdepth and few ANDs per bit
> https://eprint.iacr.org/2018/181.pdf

Improved Filter Permutators: Combining Symmetric Encryption Design, Boolean Functions, Low Complexity Cryptography, and Homomorphic Encryption, for Private Delegation of Computations
> https://eprint.iacr.org/2019/483.pdf

Transciphering Framework for Approximate Homomorphic Encryption (Full Version)
> https://eprint.iacr.org/2020/1335.pdf

Transciphering, using FiLIP and TFHE for an efficient delegation of computation
> https://eprint.iacr.org/2020/1373.pdf

Pasta: A Case for Hybrid Homomorphic Encryption
> https://eprint.iacr.org/2021/731.pdf

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