Hardware Implementation of BORON Cipher in CBC Mode for RFID Tags

Abstract

In today's era, RFID tags allow giving digital identity to almost every object in the world. These devices find their applications in various day to day activities such as logistic chain management, access control, Inventory management, RFID smart cards, price tagging, various health monitoring devices etc. The communication in these devices is vulnerable to various attacks such as replay attacks, Denial of Service attacks, man-in-the-middle attack etc. To provide security against these attacks cryptographic algorithms for providing security are required to be embedded in these tags. The conventional cryptographic algorithms such as AES and ECC provide a highly secure encryption and authentication mechanism. But these algorithms require a larger area for their implementation. According to NIST, a low-cost RFID tag requires 1000-10,000 gate equivalents (GE) for its implementation. Out of these gates, around 200-2000 Gate Equivalents (GEs) are reserved for security. Since these tags are constrained in terms of area, memory, and power, so the conventional algorithms such as AES, ECC do not perform well in these tags. National Institute of Standards and Technology (NIST) has recommended using lightweight cryptographic algorithms for these low -cost devices. This thesis work attempts to provide encryption-authentication scheme for low -cost RFID tags by adhering to the area constraints for security in these tags. For encryption, a lightweight block cipher BORON has been used as an encryption scheme. The 64-bit implementation of BORON required Gate Equivalents nearly equal to 2000 GE. To provide authentication some extra circuitry is required and hence exceeding the Gate Equivalents beyond 2000. So, a lightweight implementation has also been done by reducing the number of s-boxes and then embedding an authentication mechanism to it. Authentication has been done using an arbiter PUF. The experimental results show that for this lightweight implementation, encryption-authentication together required 106 FPGA slices and 3190 GEs thereby making this scheme suitable for providing security in low-cost RFID tags.