Cooperative Public Key Authentication Protocol in Wireless Sensor Network

Recent measurements for Public Key Cryptography (PKC) protocols on 8-bit wireless sensor nodes showed optimistic results. It has been shown that Elliptic Curve Cryptography (ECC) is quite applicable to WSN. Still, PKC is much expensive in terms of computation and memory compared by the Symmetric Key Cryptography (SKC). In addition, in PKC, each public key needs to be authenticated before it’s used. We believe that sooner or later, PKC will be widely deployed in WSN. Therefore, we present a cooperative distributed public key authentication scheme that does not require any cryptographic overhead. In our scheme, each node is let to store a few number of hashed keys for other nodes. When a public key authentication is required, nodes who store this key help in authenticating it in a distributed and cooperative way. We consider the constrained resources of the sensor node. Additionally, we extend our scheme to fit with small range of authentication error.