SIT: A Lightweight Encryption Algorithm for Secure Internet of Things (1704.08688v2)

Abstract: The Internet of Things (IoT) being a promising technology of the future is expected to connect billions of devices. The increased number of communication is expected to generate mountains of data and the security of data can be a threat. The devices in the architecture are essentially smaller in size and low powered. Conventional encryption algorithms are generally computationally expensive due to their complexity and requires many rounds to encrypt, essentially wasting the constrained energy of the gadgets. Less complex algorithm, however, may compromise the desired integrity. In this paper we propose a lightweight encryption algorithm named as Secure IoT (SIT). It is a 64-bit block cipher and requires 64-bit key to encrypt the data. The architecture of the algorithm is a mixture of feistel and a uniform substitution-permutation network. Simulations result shows the algorithm provides substantial security in just five encryption rounds. The hardware implementation of the algorithm is done on a low cost 8-bit micro-controller and the results of code size, memory utilization and encryption/decryption execution cycles are compared with benchmark encryption algorithms. The MATLAB code for relevant simulations is available online at https://goo.gl/Uw7E0W.

• The paper introduces SIT, a lightweight symmetric key block cipher designed for resource-constrained IoT devices, balancing security and computational efficiency.
• SIT is a 64-bit Feistel-SP hybrid cipher completing encryption in five rounds, achieving efficiency shown by a 3006 cycle count on an ATmega 328 platform.
• Evaluated against cryptanalysis techniques, SIT demonstrates robustness suitable for practical, secure data transmission in energy-limited IoT environments.

Summary of "SIT: A Lightweight Encryption Algorithm for Secure Internet of Things"

The paper explores the development of a lightweight encryption algorithm, named Secure IoT (SIT), specifically tailored for the Internet of Things (IoT). The primary concern addressed in the paper is the performance inefficiency and potential security vulnerabilities of traditional encryption algorithms when applied to resource-constrained IoT devices. These devices, due to their limited power and computational capabilities, necessitate an encryption technique that balances security with efficient resource utilization.

Core Contributions

The authors introduce SIT, a symmetric key block cipher, which is characterized by a 64-bit key and plaintext. The cipher combines features of both Feistel and substitution-permutation (SP) networks, thereby leveraging the benefits of both architectures to optimize security and computational efficiency. The encryption process in SIT is designed to be completed in five rounds, significantly reducing computational complexity and energy consumption when compared to conventional algorithms, which often require more rounds.

Performance and Security Analysis

Key aspects of the SIT algorithm include:

• Key Expansion: The key expansion module of SIT employs a modified Khazad block cipher approach, which efficiently derives five unique keys using a series of linear and non-linear transformations over a 64-bit input key. The structure ensures a robust key derivation that is resistant to key-related attacks.
• Efficiency in Encryption and Decryption: The encryption and decryption processes are almost identical, optimizing resource use even further—a feature intrinsic to the Feistel structure. Moreover, the computational operations in each round of encryption are applied on 4-bit data segments to enhance computational efficiency.
• Security Strength: The algorithm's structure provides robustness against both known linear and differential cryptanalysis techniques, as well as key-related attacks such as weak keys and related key attacks. The hybrid nature of the algorithm, with uniform transformations across rounds, complements its security credentials.

Experimental Evaluation

The researchers validate SIT by implementing it on an AVR-based ATmega 328 platform. Key performance metrics include a cycle count of 3006 for completing encryption and decryption, which showcases its efficiency compared with other lightweight algorithms. Furthermore, SIT demonstrates favorable results in memory utilization, and its entropy and correlation tests using image data confirm its capability to produce high-quality pseudo-random outputs.

Implications and Future Research

SIT is positioned as a practical encryption solution for IoT contexts. By achieving a balance between security robustness and computational efficiency, it addresses the critical need for lightweight cryptography in the emerging IoT landscape. Practically, SIT provides a viable framework for secure data transmissions in environments where power and processing capabilities are inherently limited.

Further avenues for research could include exploring potential optimizations for specific hardware platforms such as FPGAs, given their capability for parallel computation, which might enhance throughput. Additionally, varying the algorithm's architecture and key lengths could yield insights into scalability and security trade-offs, enhancing SIT's applicability across diverse IoT architectures.

In conclusion, the development of efficient, lightweight encryption algorithms like SIT is pivotal in ensuring the secure and sustainable growth of IoT networks, highlighting significant steps forward in aligning security solutions with the unique demands of IoT environments.