In this paper, we focus on the problem of key distribution that permits local broadcast authentication. We focus on four types of graphs (1) star graphs, (2) bipartite graphs, (3) planer graphs and (4) fully connected graphs. For star graphs, we show that as n, the number of satellite nodes in the star network, tends to ∞, it suffices to maintain log n + 1/2 log log n + 1 secrets at the center ...

One of the most interesting research topics in cryptography is finding schemes for an efficient fully-homomorphic encryption (FHE), preferably information-theoretically secure schemes, which are not based on unproven computational hardness assumptions. The greatest breakthrough in the field of FHE schemes was made by Gentry [7] in 2009, and since then there were some interesting developments, e...

A core property of program semantics is that local reasoning about program fragments remains sound even when the fragments are executed within a larger system. Mathematically this property corresponds to monotonicity of refinement : if A refines B then C(A) refines C(B) for any (valid) context defined by C(·). In other work we have studied a refines order for information flow in programs where ...

A vendor has several secrets which he regards as of equal worth and importance. He is willing to sell any of these secrets to a buyer. The bargain is said to be secure when the following two conditions are satisfied: 1) the buyer can only obtain one secret if he pays for only one secret, and 2) the vendor will not be able to find out which secret the buyer picked. This cryptographic problem is ...