Faster Multi-exponentiation through Caching: Accelerating (EC)DSA Signature Verification

We consider the task of computing power productsQ 1ik gei i ("multi-exponentiation") where base elements g2, . . ., gk are fixed while g1 is variable between multi-exponentiations but may repeat, and where the exponents are bounded (e.g., in a finite group). We present a new technique that entails two different ways of computing such a result. The first way applies to the first occurrence of any g1 where, besides obtaining the actual result, we create a cache entry based on g1, investing very little memory or time overhead. The second way applies to any multi-exponentiation once such a cache entry exists for the g1 in question: the cache entry provides for a significant speed-up. Our technique is useful for ECDSA or DSA signature verification with common domain parameters and recurring signers.

• Type: Journal
• Year: 2008
• Where: SCN
• Authors: Bodo Möller, Andy Rupp
• Keywords: Base Elements, Cache Entry, Communications, ProductsQ 1ik Gei, SCN 2008