WIPR Public Key Identi cation on Two Grains of Sand
Yossi Oren, Martin Feldhofer · 2008
We revisit a public key scheme presented by Shamir in [16] (and simultaneously by Naccache in [12]) and examine its applicability for general-purpose RFID tags in the supply chain. Using a combination of new and established space-saving methods, we present WIPR a fulledged public key identi cation scheme which is secure yet highly e cient. 1024-bit WIPR ts completely (including RAM) into 5705 gate equivalents and has a mean current consumption of 10.88μA. The main novelty in our implementation is the replacement of the long pseudorandom sequence, originally stored on EEPROM in [16], by a reversible stream cipher using less than 300 bits of RAM. We show how our scheme can be extended to o er tag-to-reader and reader-to-tag authentication and how it can be t into the existing RFID supply chain infrastructure.