Private Decision Tree Evaluation with Constant Rounds via (Only) Fair SS-4PC

Multiparty computation (MPC) is a cryptographic method that enables a set of parties to compute an arbitrary joint function of the private inputs of all parties and does not reveal any information other than the output. MPC based on a secret sharing scheme (SS-MPC) and garbled circuit (GC) is known as the most common MPC schemes. Another cryptographic method, homomorphic encryption (HE), computes an arbitrary function represented as a circuit by using ciphertexts without decrypting it. These technologies are in a trade-off relationship for the communication/round complexities, and the computation cost.