A Low-Cost ECC Coprocessor for Smartcards

Abstract. In this article we present a low-cost coprocessor for smartcards which supports all necessary mathematical operations for a fast calculation of the Elliptic Curve Digital Signature Algorithm (ECDSA) based on the finite field GF(2m ). These ECDSA operations are GF(2m ) addition, 4-bit digit-serial multiplication in GF(2m ), inversion in GF(2m ), and inversion in GF(p). An efficient implementation of the multiplicative inversion which breaks the 11:1 limit regarding multiplications makes it possible to use affine instead of projective coordinates for point operations on elliptic curves. A bitslice architecture allows an easy adaptation for different bit lengths. A small chip area is achieved by reusing the hardware registers for different operations.

• Type: Conference
• Year: 2004
• Where: CHES
• Authors: Harald Aigner, Holger Bock, Markus Hütter, Johannes Wolkerstorfer
• Keywords: CHES 2004, Cryptography, ECDSA Operations, Elliptic Curve Digital Signature Algorithm, Necessary Mathematical Operations