A Generic Approach to Improving Diffie–Hellman Key Agreement Efficiency for Thin Clients
Hung‐Yu Chien · The Computer Journal · 2015
Authenticated Diffie–Hellman key (D-H key) agreement is the de facto standard for establishing secure session keys in many security systems. However, the modular exponentiation computation of D-H key puts a heavy load of those thin clients like Radio Frequency IDentification (RFID), NFC and Zigbee, where either the computational capacity or the battery is limited and precious. Therefore, many standards and implementations of these thin clients opt out key agreement schemes to meet computational efficiency requirements thereby accepting some security risks. As these devices are becoming more popular and security threats are increasing, it is desirable to reduce the computational load of key agreement while still providing sound security. In this paper, we propose a new problem—the modified Computational Diffie–Hellman Problem (MCDHP) and prove its security being equivalent to the Computational Diffie–Hellman Problem. Based on the MCDHP, we propose a general technique to enhance the computational load for thin clients when establishing secure D-H keys. The proposed approach achieves the same security of conventional authenticated D-H key agreement except the perfect forward secrecy. Examples of secure applications on existing D-H key agreement schemes are demonstrated in this paper.