We describe protocols for secure computation of the sum, product, and some other functions of two or more elements of an arbitrary constructible ring, without using any one-way functions. One of the new inputs that we offer here is that, in contrast with other proposals, we conceal intermediate results of a computation. For example, when we compute the sum of k numbers, only the final result is...

We revisit the question of secure multiparty computation (MPC) with two rounds of interaction. It was previously shown by Gennaro et al. (Crypto 2002) that 3 or more communication rounds are necessary for general MPC protocols with guaranteed output delivery, assuming that there may be t ≥ 2 corrupted parties. This negative result holds regardless of the total number of parties, even if broadca...

Private comparison is fundamental to secure multiparty computation. In this study, we propose novel protocols to privately determine [Formula: see text], or [Formula: see text] in one execution. First, a 0-1-vector encoding method is introduced to encode a number into a vector, and the Goldwasser-Micali encryption scheme is used to compare integers privately. Then, we propose a protocol by usin...

In this paper, we propose a round efficient unconditionally secure multiparty computation (UMPC) protocol in information theoretic model with n > 2t players, in the absence of any physical broadcast channel, which communicates O(n4) field elements per multiplication and requires O(n log(n) + D) rounds, even if up to t players are under the control of an active adversary having unbounded computi...

Multiplicative monotone span program is one of the important tools to realize secure multiparty computation. It is essential to construct multiplicative monotone span programs for secure multiparty computations. For any access structure, Cramer et al. gave a method to construct multiplicative monotone span programs, but its row size became double, and the column size also increased. In this pap...

Oblivious transfer is widely used in secure multiparty computation. In this paper, we propose a game theoretic analysis of this primitive and discuss how a protocol for efficient rational oblivious transfer should be in the real world.

We present a multiparty computation protocol that is unconditionally secure against adaptive and active adversaries, with communication complexity O(Cn)k + O(Dn)k + poly(nκ), where C is the number of gates in the circuit, n is the number of parties, k is the bitlength of the elements of the field over which the computation is carried out, D is the multiplicative depth of the circuit, and κ is t...

Substantial efforts have been spent on characterizing the round complexity of various cryptographic tasks. In this work we study the round complexity of secure multiparty computation in the presence of an active (Byzantine) adversary, assuming the availability of secure point-to-point channels and a broadcast primitive. It was recently shown that in this setting three rounds are sufficient for ...

We present here a generalization of the work done by Rabin and Ben-Or in [RBO]. We give a protocol for multiparty computation which tolerates any active adversary structure based on the existence of a broadcast channel, secure communication between each pair of participants, and a monotone span program with multiplication tolerating the structure. The secrecy achieved is unconditional although ...

One of the most important problems facing any distributed application over a heterogeneous network is the protection of private sensitive information in local terminals. A subfield of cryptography called secure multiparty computation (SMC) is the study of such distributed computation protocols that allow distrusted parties to perform joint computation without disclosing private data. SMC is inc...