Unconditional Byzantine Agreement and Multi-Party Computation Secure Against Dishonest Minorities from ScratchUnconditional Byzantine Agreement and Multi-Party Computation • June 27th, 2022
Abstract. It is well-known that n players, connected only by pairwise secure channels, can achieve unconditional broadcast if and only if the number t of cheaters satisfies t < n/3. In this paper, we show that this bound can be improved — at the sole price that the adversary can pre- vent successful completion of the protocol, but in which case all players will have agreement about this fact. Moreover, a first time slot during which the adversary forgets to cheat can be reliably detected and ex- ploited in order to allow for future broadcasts with t < n/2. This even allows for secure multi-party computation with t < n/2 after the first detection of such a time slot.
Unconditional Byzantine Agreement and Multi-party Computation SecureUnconditional Byzantine Agreement and Multi-Party Computation • April 22nd, 2002
Abstract. It is well-known that n players, connected only by pairwise secure channels, can achieve unconditional broadcast if and only if the number t of cheaters satisfies t < n/3. In this paper, we show that this bound can be improved – at the sole price that the adversary can prevent successful completion of the protocol, but in which case all players will have agreement about this fact. Moreover, a first time slot during which the adversary forgets to cheat can be reliably detected and exploited in order to allow for future broadcasts with t < n/2. This even allows for secure multi-party computation with t < n/2 after the first detection of such a time slot.
