AN EFFICIENT AND PROVABLY SECURE ID-BASED SIGNATURE SCHEME WITH BATCH VERIFICATIONS

[[abstract]]A secure signature scheme with providing variant batch verifications ex- tremely improves the verification performance for many cooperative and distributed appli- cations. The identity (ID)-based public key system can simplify certificate management as compared to certificated-based public key systems. With the advent of the ID-based public key system using bilinear pairings defined on elliptic curves, many ID-based sig- nature schemes have been proposed. Recently, Cha and Cheon proposed a new ID-based signature scheme which is more efficient than the previously proposed schemes, but their scheme does not offer batch verifications for multiple signatures because their scheme suffers from forgery attacks for batch verifications. To repair this drawback, Yoon et al. proposed a secure ID-based signature scheme with batch verifications. However, Yoon et al.’s scheme requires more computational time than Cha and Cheon’s scheme. In this paper, we propose an efficient and provably secure ID-based signature scheme supporting variant kinds of batch verifications. In the random oracle model and under the computa- tional Diffie-Hellman assumption, we show that our scheme is secure against existential forgery attacks under various kinds of batch verifications. According to performance analysis, our scheme with batch verifications has the best performance as compared to the previously proposed schemes