On the scalability of an efficient “Nonscalable” key distribution scheme

Some important requirements of key distribution schemes for many emerging applications involving resource constrained devices (for example, ad hoc and sensor networks) are 1) low complexity; 2) the ability to support unmediated establishment of security associations and 3) scalability. We propose a novel key distribution scheme based on an elegant scheme proposed by Leighton and Micali (1994). While the scheme in (Leighton and Micali, 1994) was intended to be an alternative to Kerberos (employing a trusted server for mediation), the proposed modifications are towards realizing a scheme for nonmediated establishment of pairwise secrets. We enumerate several compelling advantages of the proposed scheme over existing schemes in the literature.