C2S, a New Cryptographic Command Set for Smart Card Operating System

摘要

Smart card is a miniature computer with very limited hardware and software resources. Like any computer, an operating system is needed to manage the card hardware and software resources. Several smart card operating systems of different types were developed for this purpose. The basic functions of these operating systems are handling the card input/out process, managing the file system, managing communication with card users/ application programs and data processing with the cryptographic algorithms embedded on the card, if any. This paper aims to make the smart card smarter by expanding its command set to include cryptographic commands. The proposed command set enables the card issuer to deeply access the embedded cryptographic cipher algorithms and customize their building blocks after card development. The proposed command set is capable of on-card generation of new cryptographic building blokes like permutations, linear transformations and substitution boxes. For the purpose of validation, testing and demonstration of the new features, the new command set has been developed in embedded C language and implemented on an open platform smart card.