THE KRYPTOKNIGHT FAMILY OF LIGHTWEIGHT PROTOCOLS FOR AUTHENTICATION AND KEY DISTRIBUTION

An essential function for achieving security in computer networks is r eliable authentication of communicating parties and network components . Such authentication typically relies on exchanges of cryptographic m essages between the involved parties, which in turn implies that these parties be able to acquire shared secret keys or certified public key s. Provision of authentication and key distribution functions in the p rimitive and resource-constrained environments of low-function network ing mechanisms, portable, or wireless devices presents challenges in t erms of resource usage, system management, ease of use, efficiency, an d flexibility that are beyond the capabilities of previous designs suc h as Kerberos or X.509. This paper presents a family of light-weight a uthentication and key distribution protocols suitable for use in the l ow layers of network architectures. All the protocols are built around a common two-way authentication protocol. The paper argues that key d istribution may require substantially different approaches in differen t network environments and shows that the proposed family of protocols offers a flexible palette of compatible solutions addressing many dif ferent networking scenarios. The mechanisms are minimal in cryptograph ic processing and message size, yet they are strong enough to meet the needs of secure key distribution for network entity authentication. T he protocols presented have been implemented as part of a comprehensiv e security subsystem prototype called KryptoKnight, whose software and implementation aspects are discussed in [16], and which is the basis for the recently announced IBM Network Security Program product.