Block cipher attacks have found new aspects, due to the advancement of the technology and the development of the software and hardware tools. In many cases, the attackers try to use the weaknesses of the block ciphers implementation, instead of the theoretical cryptanalyses. Increasing the attacker’s accessibility to the details of the block ciphers implementation will increase the chance of success of his attacks. Hence, it is important to design secure block cipher schemes, those are unbreakable whether the attackers have access to the details of the implementation or not. In this paper, first we will introduce the different models of the block ciphers implementation, then we will explain the fundamental concepts of the white-box cryptography, and why it is useful. Later we will discuss several white-box schemes.

The use of lightweight and light weight block ciphers in the Internet of Things is inevitable. Recently, Midori64 has received a lot of attention among other lightweight ciphers due to its very low power consumption. Midori64 security has been threatened by various attacks, including side channel attacks. One of the types of side channel attacks is correlation power analysis, in which an attacker can discover the encryption key by using the power leak of the cryptographic chip while the algorithm is running, data being processed and operations being executed. Masking against power analysis attacks is known as one of the most effective methods of cryptographic algorithms. The purpose of the mask is to disrupt the relationship between power consumption and ongoing operations. In this paper, an implemented version of the Midori64 code on an Atmega32 AVR micro-controller is attacked by correlation power analysis, and an encryption key with 300 blocks of plain text is discovered. After masking the Midori64 with the Boolean masking method, the attack was performed again, and the experimental results showed that the Boolean masking method could prevent key discovery.

Side-channel attacks, particularly power analysis attacks, pose a significant threat to the security of block cipher applications in hardware. These attacks can be executed using three primary methods: Simple Power Analysis (SPA), Differential Power Analysis (DPA), and Correlation Power Analysis (CPA). This paper examines the vulnerability of the SPEEDY block cipher to such power analysis attacks. In the first section, we demonstrate that the non-linear layer of the SPEEDY block cipher is susceptible to information leakage when subjected to power analysis attacks. By implementing the cipher in hardware and utilizing 1000 input samples, we establish that key-recovery attacks are feasible. The second section focuses on countermeasures to enhance the security of the SPEEDY block cipher against power analysis attacks. We propose a secure implementation method that employs Domain-Oriented Masking (DOM). Using the SILVER tool and the T-test method, we show that the secured version of the SPEEDY block cipher effectively mitigates the vulnerabilities and information leakages present in the original version when exposed to power analysis attacks.