Design Of Encrypted NFC Tag Digital Baseband For IoT Data Security

In recent years,with the rapid development of Internet of Things technology,the blueprint of smart city construction has gradually become a reality.The Internet of Things system connects real objects and equipment to urban smart terminals through identification technology to achieve intelligent management.Near Field Communication(NFC)technology has become an indispensable technology in the Internet of Things system due to its advantages of low power consumption,strong convenience,and fast operation speed.However,the security of NFC is still insufficient.Traditional NFC tags often use UID as their own identity code data,but the static and unchanged UID has the risk of being copied.Forged NFC tags can use the copied identity data to easily break through the Io T system,thereby stealing personal data of users in Io T end systems.Aiming at the problem that the identity data of traditional NFC tags is easy to copy and transfer,this paper designs a digital baseband for dynamically encrypted NFC tag chip.The SM3 cryptographic hash algorithm is integrated into the baseband design,so that the tag will generate an unpredictable hash value to refresh its own identity code data after each round of power-on,which improves the anti-copying property of the NFC tag chip and ensures the tag identity data.At the same time,the forged tags cannot pass the authentication of the Io T system,and no longer have the authority to read the system data,thus also protecting the data security in the Io T terminal system.The main work of this paper includes:(1)Based on the ISO/IEC 14443-A communication protocol,combined with the SM3cryptographic hash algorithm,the digital baseband of the tag is divided into modules,and the respective state machines are formulated according to the functions of the modules.Verilog is used to write the digital baseband to realize the specified functions.The low-power method optimizes the overall power consumption of the tag,and the correctness of the functions of each module is verified through pre-simulation.At the same time,the generation of the dynamic authentication code is checked.The function of the tag baseband meets the design requirements;Through the FPGA test board and commercial reading PN532communication to further examine the vulnerabilities of the digital baseband design.(2)After the board-level verification is passed,gate-level circuit conversion and layout are implemented for the tag digital baseband under the TSMC 0.18μm CMOS process.After imposing different gated clock constraints,the synthesis report is analyzed,and the design constraints with the best area and power consumption results are selected to convert the gate-level netlist to the digital baseband.The synthesized encrypted tag digital baseband area is177947.30μm~2,Power consumption is 38.67μW.After completing the implementation of the encrypted tag chip layout,in order to improve the success rate of tape-out,the chip has been checked for timing and physical verification.(3)Build a chip test platform to complete the test of the basic communication function and dynamic encryption authentication code generation function of the NFC tag chip.At the same time,the SM3 encryption algorithm calculator is used on the computer to verify the correctness of the authentication code data.After testing,the function of the NFC tag chip is correct,power consumption and area meet the design requirements.