Key Validation Using Weighted-Edge Web of Trust Model

Abstract

Public key cryptography is widely used in the establishment of secure communication. An important issue in the use of public key cryptography is to ensure that a public key actually belongs to its owner. This problem is referred to as the key validation problem. One solution to this key validation problem is the centralized public key infrastructure (PKI) model ([1]). A second alternative is the decentralized Web of Trust model ([2]). In this model a user depends on digital certificate introduced by other users, who may be trustworthy or otherwise, to establish the binding between a public key and its owner. In this work we propose to model the trust relationship between users as weighted edges. We propose an algorithm to find trusted paths and thus validate public keys. The proposed algorithm is simple and has a low complexity both in terms of time and space.