Toward Practical Threshold FHE: Low Communication, Computation and Interaction

Fully Homomorphic Encryption (FHE) is a promising primitive for evaluating arbitrary circuits while maintaining the user's privacy with an optimal round of communications. However, extending FHE to Threshold FHE and transitioning from two-party to multi-party settings presents some challenges, such as distributed key generation or decryption. When focusing on distributed decryption, it requires an exponentially large ciphertext modulus, which degrades communication efficiency.