Securing mobile ad hoc networks with certificateless public keys

This paper studies key management, a fundamental problem in securing mobile ad hoc networks (MANETs). We present IKM, an ID-based key management scheme as a novel combination of ID-based and threshold cryptography. IKM is a certificateless solution in that public keys of mobile nodes are directly derivable from their known IDs plus some common information. It thus eliminates the need for certificate-based authenticated public-key distribution indispensable in conventional public-key management schemes. IKM features a novel construction method of ID-based public/private keys, which not only ensures high-level tolerance to node compromise, but also enables efficient network-wide key update via a single broadcast message. We also provide general guidelines about how to choose the secret-sharing parameters used with threshold cryptography to meet desirable levels of security and robustness. The advantages of IKM over conventional certificate-based solutions are justified through extensive simulations. Since most MANET security mechanisms thus far involve the heavy use of certificates, we believe that our findings open a new avenue towards more effective and efficient security design for MANETs.