Design And Physical Implementation Of Tag’s Baseband Baseon SMS4 Authentication

With the increasing popularity of UHF RFID technology in the field of logistics, its fields will be more widely involved, thus information security problems of passive UHF RFID tags are also more and more important. In order to increase security when the tag proceeds secure authentication with the reader, based on symmetric encryption bidirectional authentication protocol which be used to security identify in national standards for information technology- radio frequency identification air interface protocol at 800 / 900 MHz, this paper designed a RFID tag with secure authentication and a SMS4 encryption algorithm,according to the basic architecture and designing ideas of tags without secure authentication. SMS4 encryption algorithm proposed in this paper is a cipher applied to wireless LANs, since in this cryptographic each encryption algorithm or decryption process is operated for a set of data, and this different from stream cipher that only conduct one bit, so it can be nanmed as block cipher. Because a combination structure of non-linear iterative structure and linear structure is used for encryption or decryption process in SMS4 algorithm, so compared to XOR encryption methods proposed in protocol, this algorithm stronger security, and higher reliability.Research focus of this paper is to design a low power, small area of SMS4 algorithm structure, and combined with the basic framework of the tag to design a tag digital baseband based SMS4 encryption algorithm.Through analysis on the expanded key, S boxes, T operation, encryption and decryption mechanisms in SMS4 algorithm, the paper describes several different basic design frameworks of SMS4 algorithms and their implementation, including full-loop structure, the structure of loop unrolling, and pipeline structure. Based on difference between these types of framework in the area, power consumption and speed, combined with the basic framework and no SMS4 encryption algorithm tag framework in the tag, this paper designs a low power consumption, small area tag baseband based SMS4 encryption algorithm by improving the SMS4 digital baseband implementation in framework.Finally, with EDA software in SMIC 0.18μm technology library, this paper did logic synthesis DC, physical implementation, post-simulation and verification for the tag baseband on this design. Simulation and verification results show that this design tag based SMS4 encryption algorithm can complete mutual authentication based on symmetric encryption, and can also achieve normal reading, writing, inactivation and locking tags. Power SMS4 algorithm introduced is controlled within 7μw, the number of gates SMS4 algorithm occupies is about 4000, and the indicators show that this tag meet the design requirements, and achive the predetermined goals.