Denial of Service Resistance in Key Establishment

Denial of service (DoS) attacks are an increasing problem for network connected sys-tems. Key establishment protocols are applications that are particularly vulnerable to DoS attack as they are typically required to perform computationally expensive cryp-tographic operations in order to authenticate the protocol initiator, and to generate the cryptographic keying material that will subsequently be used to secure the communi-cations between initiator and responder. The goal of denial of service resistance in key establishment protocols is to ensure that attackers cannot prevent a legitimate initia-tor and responder deriving cryptographic keys without expending resources beyond a responder determined threshold. In this work we review the strategies and techniques used to improve resistance to denial of service attacks. Three key establishment proto-cols implementing denial of service resistance techniques are critically reviewed and the impact of misapplication of the techniques on denial of service resistance is discussed. Recommendations on effectively applying resistance techniques to key establishment protocols are made