Time Cost Evaluation for Executing RFID Authentication Protocols Yingjiu Li, Ph.D. Associate Professor School of Information Systems Singapore Management University Singapore

Introduction Time cost of cryptographic operations Time cost of communications Protocol classification and time cost Conclusion Contents

Introduction Time cost of cryptographic operations Time cost of communications Protocol classification and time cost Conclusion Contents

Time cost for executing an authentication protocol consists of three parts –Tr: time cost for cryptographic operations and looking up a database at a reader side –Tt: time cost for cryptographic operations at a tag side –Tc: time cost of communication between a reader and a tag Objective –Provide a benchmark for protocol development Introduction

Development Environment –Emulator: UHF DemoTag, IAIK, TU Graz, Austria –Reader: CAEN WA828, Italy We focus on Tt and Tc –Tr is negligible as compared with Tt and Tc Introduction Atmega 128 microcontroller

Introduction Time cost of cryptographic operations Time cost of communications Protocol classification and time cost Conclusion Contents

Time cost for a DemoTag to run cryptographic operations: –Hashing: MD5, SHA-1, SHA-256, SHA-512 –Crypto: AES-128, AES-192, AES-256 –Ultra-lightweight: PRESENT-80 Time cost of cryptographic operations

Time cost for a DemoTag to run cryptographic operations: –Hashing: MD5, SHA-1, SHA-256, SHA-512 –Crypto: AES-128, AES-192, AES-256 –Ultra-lightweight: PRESENT-80 Time cost of cryptographic operations

Introduction Time cost of cryptographic operations Time cost of communications Protocol classification and time cost Conclusion Contents

Time cost of communications –Tag-to-tag Read/Write operations Read: 0007ms / 16-bit word Write: 16.7ms / 16-bit word –Reader-to-tag Read/Write operations Time cost of communications

Introduction Time cost of cryptographic operations Time cost of communications Protocol classification and time cost Conclusion Contents

Four types of authentication protocols –RAO: reader authentication only A reader authenticates its legitimacy to a tag –TAO: tag authentication only A tag authenticates its legitimacy to a reader –TRA: tag-then-reader authentication A tag authenticates its legitimacy to a reader and then the reader authenticates its legitimacy to the tag –RTA: reader-then-tag authentication A reader authenticates its legitimacy to a tag and then the tag authenticates its legitimacy to the reader Protocol classification and time cost

Four types of authentication protocols –Different types of protocols have different numbers of rounds of communications between a reader and a tag Communication time Tc takes the major time cost for executing a protocol, as shown in the figure in the next slide Protocol classification and time cost

Communication time Tc takes the major time cost for executing a protocol, as shown in the figure Protocol classification and time cost

Introduction Time cost of cryptographic operations Time cost of communications Protocol classification and time cost Conclusion Contents

We have conducted pioneering study for time cost evaluation of RFID authentication protocols Future work –Conduct some other asymmetric cryptographic operations like ECC, RSA, etc –Conduct experiments on WISP tag platform Conclusion

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