The BlueJay Ultra-Lightweight Hybrid Cryptosystem

Abstract

We report on the development of Blue Jay, a hybrid Rabin-based public key encryption cryptosystem that is suitable for ultra-lightweight (total 2000-3000 GE) platforms such as micro sensors and RFID authentication tags. The design is related to authors Passerine and the Oren-Feldhofer WIPR proposals, but is suitable to a wider array of applications. The encryption mechanism is significantly faster and the implementation more lightweight than RSA (even with public exponent 3) and ECC with the same security level. Hardware implementations of the asymmetric encryption component of the hybrid cryptosystem require less than a thousand gate equivalents in addition to the memory storage required for the payload and public key data. An inexpensive, mill scale MCU SoC Blue Jay implementation is reported and compared to RSA-AES on the same platform. The private key operation (not performed by the light-weight device but by the sensor network base station or a data acquisition reader) has roughly the same complexity as the RSA private key operation.