Study On Design And Application Of PUF Based On Flexible Electronics

While the widespread application of the IOT brings people huge economic benefits and convenience in life,a series of security issues are exposed gradually.There are many types and huge numbers of IOT devices,it is difficult to obtain a unified standard to manage its identity.During the process of exchanging information between terminals,the sensors or RFID are mostly used.This method to obtain information is very convenient,but an adversary can intercept specific information by monitoring the communication channel.The storage and computing capabilities of most IOT terminals are limited by volume,and traditional encryption authentication schemes are difficult to apply.Important information stored in the device and the wireless channel without encryption can be easily forged and tampered with.A lightweight,low-cost encryption scheme is required to protect private information.PUF is widely used in active anti-counterfeiting technology to prevent possible copy attacks on devices.Although the overhead required by the PUF circuit itself is not high,it still has a certain degree of difficulty compared with the IOT device chips which require smaller computing and storage resources.And with the further expansion of the application range,more devices are expected to be attached to a flexible substrate for work,which undoubtedly further increases the difficulty of designing related chips.Therefore,the IOT urgently needs a reliable,low-cost,and lightweight protection measure to protect the privacy of the information stored in the device itself.As a key technology in the IOT,flexible electronics has a simple production process,lower cost,unique ductility and good electrical properties.Therefore,how to use flexible electronics to design and implement a PUF scheme that is more suitable for protecting IOT devices had been deeply explored in this work.A PUF scheme based on flexible electronics was proposed.The resistance value is used as a parameter to generate a characteristic response,and the resistance of wire is chosen to generate a random analog voltage signal.The analog voltage would fluctuate around the middle value of VCC in FPGA.A two-cascaded inverter is introduced to realize the conversion of analog voltage to digital voltage as ‘0' or ‘1'.A 2×16 PUF circuit was designed and converted into a two-dimensional plane pattern by Coredraw.Then it was realized on the high-gloss photo paper and sintered in an oven at 120 ? for 20 min.The response extraction circuit was built on the Cyclone-4 FPGA of Altera to realize the automatic extraction of PUF.And a PCB transfer board was designed to realize the effective connection between the flexible PUF circuit and the FPGA.The experiment result shows that the PUF scheme has good randomness and an ideal uniqueness of 0.50080.The average temperature reliability of PUF measured between 20 ? and 75 ? is99.79% which means it has ideal temperature reliability.The flexibility reliability of PUF is tested between bending-25 ° and +25 °,and the result shows that PUF has good reliability between-20 ° and +20 °,about 99.12%.The reproducibility of proposed PUF design is tested under the operating voltage of FPGA VCC and 28 ? room temperature.Its value is 99.26% which means that our design has good reproducibility.In view of the security issues that have been exposed in the IOT,the specific application scenarios of the proposed PUF based on flexible electronics are explored.An RFID security authentication protocol is proposed,which uses PUF based on flexible electronics to generate a unique ID for the tag.The ID is divided into two parts.The first part is used to retrieve and authenticate the identity of the tag by the database.The second part of the ID is used to authenticate the legal identity of the database by the tag.Only after the tag successfully authenticates the legal identity of the database,the internal information is allowed to be modified.The PUF circuit can be integrated with the antenna and other modules in tag.A controller in tag is designed to correctly separate the data stream received by the antenna into corresponding signals,and the functional simulation of the controller is realized on the FPGA.This scheme can save the storage and computing resources of the tag chip,and an error correction mechanism is introduced to improve the reliability of the authentication protocol.The PUF based on flexible electronics is combined with fuzzy vault algorithm to encrypt data in communication.When the PUF key is entered correctly,the data can be decrypted,thereby realizing secure transmission.This scheme has a high authentication success rate and lower manufacturing cost,and the increase in the number of confusion points in the database will not interfere with the authentication success rate.PUF based on flexible electronics can realize the security protection of IOT hardware devices and save hardware resources.It also expands the dimensions of the working environment of IOT devices and have a broader application prospect.