A PROTOCOL FOR ESTABLISHING SECURE COMMUNICATION CHANNELS IN A LARGE NETWORK

Knowledge exchange and information access in a truly distributed netwo rk often require transmitting of data through an open media. Consequen tly, data presented through such an environment are vulnerable to atta cks. To minimize such vulnerability, data transformation or encryption /decryption techniques are often utilized among senders and receivers to achieve secure communication. Since data encryption/decryption requ ires sharing of a secret session key, finding an efficient way to dist ribute the session key in a large-scale, truly distributed network has been a nontrivial task. This paper presents a protocol for efficientl y distributing session keys in such an environment to establish a secu re channel. We assume the target network consists of many locally trus ted centers, and each center has many users attached to it. The scheme incorporates the public-key distribution concept and the RSA encrypti on scheme as the basic mathematical tools, but eliminates the storage problem associated with huge public-key files. In addition, the propos ed scheme has the added feature of providing the authenticate session key to the two parties in a secure communication.