In order to hold secure electronic conference in Communication networks via insecure channels, a conference key distribution system should be constructed. The conference key distribution system (CKDS) is used for distributing a conference key shared among the participants of the conference and hence secure communications are achieved. In this paper, by using the secret sharing scheme based on t...

We explore the minimal assumptions that are necessary for nontrivial argument systems, such as Kilian’s argument system for NP with polylogarithmic communication complexity [K92]. We exhibit an oracle relative to which there is a 2-round argument system with poly-logarithmic communication complexity for some language in NP, but no one-way functions. The language lies outside BPTime(2o(n)), so t...

is similar to the proof of Theorem 2.4 ((rst direction), together with the second part of Lemma 4.3 that guarantees that D 1 (e) = D 1 (e f) D 1 (e g). Using the last two theorems, we get Let us now brieey discuss the case of computing general relations and not necessarily functions. The equality in Lemma 4.3 part (1), does not hold anymore. However, by FKN91] the two sides cannot be too far. A...

The dissemination of knowledge derived from research and scholarship has a fundamental impact on the ways in which society develops and progresses, and at the same time it feeds back to improve subsequent research and scholarship. Here, as in so many other areas of human activity, the internet is changing the way things work; two decades of emergent and increasingly pervasive information techno...

We investigate the e ect of limiting the number of available nondeterministic bits in di erent computational models. First we relate formula size to one-way communication complexity and derive lower bounds of (n = log n) on the size of formulae with n = log n nondeterministic bits for 0 < 1=2. Next we prove a rounds-communication hierarchy for communication complexity with limited nondeterminis...