ASIC-Oriented Comparative Review of Hardware Security Algorithms for Internet of Things Applications Mohamed A. Bahnasawi 1 , Khalid Ibrahim 2 , Ahmed Mohamed 3 , Mohamed Khalifa Mohamed 4 , Ahmed Moustafa 5 , Kareem Abdelmonem 6 , Yehea Ismail 7 , Hassan Mostafa 8 1,3,5,6,8 Electronics and Electrical Communications Engineering Department, Cairo University, Giza, Egypt 2 Electronics Department, Faculty of Information Engineering and Technology, German University in Cairo, Cairo, Egypt 4 Electrical, Electronics and Communications Engineering Department, Faculty of Engineering, Alexandria University, Egypt 7,8 Center for Nanoelectronics and Devices, AUC and Zewail City of Science and Technology, New Cairo, Egypt { 1 m_bahnasawi@outlook.com; 2 khalid.mohie@student.guc.edu.eg; 3 ahmedmohamed.eece@gmail.com; 4 mohamed.mohamed@student.tut.fi; 5 ahmed_moustafa_94@yahoo.com; 6 kareem.men3em@gmail.com; 7 y.ismail@aucegypt.edu; 8 hmostafa@uwaterloo.ca } Abstract— Research into the security of the Internet of Things (IoT) needs to utilize particular algorithms that offer ultra-low power consumption and a long lifespan, along with other parameters such as strong immunity against attacks, lower chip area and acceptable throughput. This paper offers an ASIC-oriented comparative review of the most popular and powerful cryptographic algorithms worldwide, namely AES, 3DES, Twofish and RSA. The ASIC implementations of those algorithms are analyzed by studying statistical data extracted from the ASIC layouts of the algorithms and comparing them to determine the most suited algorithms for IoT hardware- security applications. The AES algorithm is found to be the most suitable algorithm for IoT applications. Keywords—Internet of Things (IoT); Hardware Security; Application Specific Integrated Circuit (ASIC); Cryptography; Cryptographic Algorithms; AES; 3DES; Twofish; RSA I. INTRODUCTION Cryptography has been used for centuries to secure communication. Due to the enormous expansion of the digital world, secure cryptographic algorithms have become intensively used in a wide number of applications such as Wireless Local Area Networks (WLAN), Wireless Sensor Networks (WSN), smart cards and medical devices. Accordingly, efficient, secure and low power cryptographic algorithms have become crucial. Many cryptographic algorithms are widely available and used in information security. They can be categorized into symmetric (private) and asymmetric (public) key cryptographic algorithms. In symmetric-key cryptography, only one key is used to encrypt and decrypt data. In contrast, asymmetric-key cryptography uses two keys, a private and a public key [1]. The public key is used for encryption while the private key is used for decryption. The RSA algorithm is an example of an asymmetric-key algorithm. Public key encryption is based on mathematical functions and is computationally intensive. Symmetric-key algorithms are suited for certain applications while asymmetric-key algorithms are better for different ones. Applications have different requirements for the cryptographic algorithms that secure them, varying in the throughput needed, the extent of immunity against attacks, power consumption, the area needed on-chip, etc. The Internet of Things (IoT) focuses mainly on low-power implementations of security algorithms. This is because most of them are related to autonomous applications or embedded systems applications (i.e. an ultra-thin sensor system [2] embedded inside clothes or biomedical applications). These applications have very limited power budgets to lengthen the lifetime of their batteries. In this paper, different symmetric-key and asymmetric- key cryptographic algorithms are investigated. ASIC implementations of these algorithms are presented and statistical data such as power consumption are compared to conclude which algorithms are the most suited for IoT security constraints. The following popular and powerful algorithms are chosen to be studied: AES, 3DES, Twofish and RSA. The rest of this paper is organized as follows. Section II gives a brief overview of each of the chosen algorithms and analyzes the immunity against attacks of each algorithm. The statistical data extracted out of the ASIC implementations are tabulated and compared in Section III. In addition, the corresponding layout implementations are presented. Finally, Section IV concludes and discusses the results of the paper. II. IMMUNITY AGAINST ATTACKS A. AES The Advanced Encryption Standard (AES) was established in 2001 by NIST as the current standard for encrypting electronic data. AES uses the Rijndael cipher, which is a symmetric-key block cipher. The Rijndael cipher supports numerous block and key sizes, but AES chooses to have a fixed block size of 128 bits and three key size variants to choose from: 128, 192 and 256. The AES therefore benefits from strong security and high flexibility. 978-1-5090-5721-4/16/$31.00 ©2016 IEEE ICM 2016 285