Two Round Multiparty Computation via Multi-key FHE

Explore a 25-minute conference talk on Two Round Multiparty Computation via Multi-key FHE presented by Daniel Wichs at Eurocrypt 2016. Delve into the fundamentals of Fully Homomorphic Encryption (FHE) and its extension to multi-key settings. Examine the concept of Multi-Party Computation and its implementation using Multi-Key FHE in a two-round protocol. Investigate the construction of Multi-Key FHE, including Learning with Errors (LWE), GSW FHE keys, encryption, and evaluation. Learn about the Gadget Matrix G and its role in the Micciancio-Peikert '12 approach. Understand the challenges of ciphertext expansion and distributed decryption in the multi-key setting. Gain insights into cutting-edge cryptographic techniques and their applications in secure multi-party computations.

Intro
Fully Homomorphic Encryption (FHE)
Background on Multi-Key FHE
Multi-Party Computation
2-Round MPC from Multi-Key FHE
Constructing Multi-Key FHE
Learning with Errors (LWE) [RO5]
GSW FHE: Keys
GSW FHE: Encryption
The GSW FHE: Evaluation
Gadget Matrix G Micciancio-Peikert '12
Extending GSW to Multi-Key Setting
Ciphertext Expansion
Distributed Decryption
Conclusions