Data transmissions between smartphone users require security solutions to protect communications. Hence, encryption is an important tool that must be associated with smartphones to keep the user’s data safe. One proven solution to enhance the security of encryption algorithms is by using 3D designs on symmetric block ciphers. Although a 3D cipher design could improve the algorithms, the existing methods enlarge the block sizes that will also expand the key sizes and encryption rounds, thus decreasing their efficiency. Therefore, we propose the LAO-3D block cipher using a 3D permutation that offers security by providing confusion and diffusion characteristics. Five security analyses were conducted to assess the strengths of LAO-3D. The findings suggest that LAO-3D achieves better results compared to other existing lightweight block ciphers, with 98.2% non-linearity, 50% bit error rates for both plaintext and key modifications, surpasses 100% of the randomness test, and is immune to differential and linear cryptanalysis attacks. Moreover, the block cipher obtains competitive performance results in software applications. From the security analyses and performance tests, it is proven that LAO-3D can provide sufficient security at low costs in mobile encryption applications.

RECTANGLE lightweight algorithm is a 64-bit block cipher using 80-bit and 128-bit key variants. A lightweight algorithm takes lesser computational power than a conventional algorithm. Implementing a lightweight algorithm in low-resource devices is more effective. To ensure the output has no pattern, randomness is an essential property for an algorithm. The NIST Statistical Test Suite is used to execute the randomness analysis. To produce 1,000 input sequences for each algorithm, nine data categories are implemented. RECTANGLE-80 and RECTANGLE-128 passed the randomness analysis with 98.73% and 98.48%. The results reveal that RECTANGLE appears to be non-random based on the 0.1% significance level. The analysis findings found weaknesses that can be explored in future research.

Lightweight block ciphers have become a standard for security protections on IoT devices. Advanced technology is required to secure the data, thus encryption is the method that can provide information security. From previous studies, comparisons of lightweight algorithms in various literature focus on their performance and implementation. However, a lack of analysis has been done on the relationship between the algorithm components and their security strength. This information is crucial for developers in designing secure algorithms. In this paper, a comprehensive systematic literature review on 101 existing lightweight algorithms is presented. This review focuses on the security aspect of lightweight algorithms that cover the identification of secure design components based on substitution and permutation. Security analysis and the evolution of lightweight algorithms are also presented. This research includes the results and discussions to observe the selections of substitution and permutation functions to analyse their impact on the security strength. Recommendations from the developer's insight on methods and considerations for designing an algorithm are also presented. Findings from the research indicate that various techniques can be used to develop a secure algorithm. Most importantly, an algorithm must be provided with confusion and diffusion properties in the design to ensure sufficient security