Streaming Verification of Graph Properties

Streaming interactive proofs (SIPs) are a framework for outsourced computation. A computationally limited streaming client (the verifier) hands over a large data set to an untrusted server (the prover) in the cloud and the two parties run a protocol to confirm the correctness of result with high probability. SIPs are particularly interesting for problems that are hard to solve (or even approximate) well in a streaming setting. The most notable of these problems is finding maximum matchings, which has received intense interest in recent years but has strong lower bounds even for constant factor approximations. In this paper, we present efficient streaming interactive proofs that can verify maximum matchings exactly. Our results cover all flavors of matchings (bipartite/non-bipartite and weighted). In addition, we also present streaming verifiers for approximate metric TSP. In particular, these are the first efficient results for weighted matchings and for metric TSP in any streaming verification model.Comment: 26 pages, 2 figure, 1 tabl

Verifiable Secret Sharing Scheme on Images using Watermarking

Abstract In this paper, we have implemented Adi Shamir's (k, n) threshold secret sharing scheme onto 24-bit bitmap images. Along with this we have used a concept of watermarking, hash function and a multilayered threshold secret sharing approach to verify the authenticity of each image share before processing instead of decrypting blindly. Moreover this verification scheme allows us to identify dishonest participants who might have gained unauthorized access on secret shares. Consequently, this proposed scheme offers a highly secure mechanism of image secret sharing, which is different from existing traditional methods. Although we have implemented this scheme on images it can easily be used on any digital format as we are dealing with streams of bits