Secured Testing of AES Cryptographic ICs for IoT Devices

Abstract

Internet of Things (IoT) devices are increasingly embedded in many aspects of our daily lives. The massive connectivity of these devices means the enormous amounts of data they transmit becomes susceptible to different types of attacks. Therefore, an IoT system demands that high security features be an integral part of the implementation of these IoT devices, which are responsible for exchanging critical and sensitive information. The proper use of Cryptography through Cryptographic ICs therefore becomes essential to securing all IoT devices. A Cryptographic IC also needs to be tested so as to ensure its correct functionality. Although various types of testing methods exist, scan-based testing is the most popular IC testing technique. When it comes to Cryptographic ICs, these scan-based testing methods can retrieve secret information stored inside them. This happens because scan chain structure provides a backdoor to hackers who can exploit easily sensitive information. Such attacks are known as scan-based side channel attacks. Therefore, it becomes absolutely essential to guarantee the security of these Cryptographic ICs which are used to secure IoT devices, and also maintain their testing capabilities to ensure their functional correctness. In this chapter, Cryptographic Algorithms used for security purposes in IoT devices are discussed, as well as various side channel attacks on AES Cryptographic ICs reported in the literature. Existing countermeasures for securing the scan chain, which is typically inserted in the AES Cryptographic ICs, are examined. In the next section of the chapter, the design and simulation results of a scan-inserted AES Crypto module are presented. The proposed methods which are used to enhance the security of the SCAN Chain of AES Crypto module are detailed. Closely examined are the results and analysis of the implemented Crypto module. The conclusion highlights achievements while completing this work and discusses future work. After reading this chapter, the reader should be able to understand the importance of the SCAN chain side channel attacks and their countermeasures in Cryptographic ICs used in IoT devices for security.