Enhancement of Security in VoIP using Modified Shamir’s Secret Sharing and Multipath Routing

Abstract

This paper proposes a novel security technique for VoIP which integrates the multipath routing and the secret key sharing. Existing techniques have used shamir’s secret scheme. A secret sharing scheme divides a secret into multiple shares by a dealer and shared among shareholders in such a way that any authorized subset of share- holders can reconstruct the secret; whereas any un-authorized subset of share- holders cannot recover the secret. If the maximal length of shares is equal to the length of the secret in a secret sharing scheme, the scheme is called ideal. If the shares corresponding to each un-authorized subset provide absolutely no information, in the information-theoretic sense, the scheme is called perfect. Shamir proposed the first (t; n) threshold secret sharing scheme and it s ideal and perfect. In this paper, two modifications of Shamir's secret sharing scheme are proposed. In the first modification, each shareholder keeps both x-coordinate and y-coordinate of a polynomial as private share. In the second modification, dealer uses polynomial with degree larger than the threshold value t to generate shares for a (t; n) threshold scheme. These two modifications are used to construct a hierarchical secret sharing scheme called Multilevel Threshold Secret Sharing (MTSS) is introduced for better security. The performance of the proposed approach is compared with the existing VoIPsec and VoIP with shamir’s secret sharing.