NFBC: an efficient FPGA based NFSR-oriented lightweight block cipher suitable for embedded system

Area of Science:

• Cryptography
• Computer Science
• Information Security

Background:

• Lightweight cryptography is crucial for resource-constrained environments.
• Existing solutions often face trade-offs between security and efficiency.
• The National Institute of Standards and Technology (NIST) has ongoing initiatives for lightweight cryptography standardization.

Purpose of the Study:

• To introduce and evaluate the NFSR-Based Block Cipher (NFBC), a novel lightweight authenticated encryption with associated data (NAEAD) scheme.
• To demonstrate NFBC's suitability for constrained environments requiring both high security and efficiency.
• To provide a practical and secure cryptographic solution for Internet of Things (IoT) and embedded systems.

Main Methods:

• Design of NFBC utilizing a Non-Linear Feedback Shift Register (NFSR), dynamic chaotic S-boxes, and a Group Permutation (GRP) mechanism.
• Rigorous security analysis including NIST Statistical Test Suite (STS), avalanche effect, Bit Independence Criterion (BIC), nonlinearity, differential, and linear cryptanalysis.
• Provable security analysis using branch-number calculations for theoretical guarantees.
• FPGA implementation on a Xilinx Artix-7 for performance and hardware overhead evaluation.
• Estimation of countermeasure overheads for side-channel and fault attack resistance.

Main Results:

• NFBC successfully passed all 15 NIST STS tests.
• Achieved near-ideal avalanche and BIC properties, with high nonlinearity across 200 S-box instances.
• Demonstrated strong resistance to classical attacks with low differential and linear probabilities.
• FPGA implementation showed superior throughput-per-area compared to NIST Round-2 and CAESAR candidates.
• Feasible overheads for masking and fault detection indicate resistance to side-channel and fault attacks.

Conclusions:

• NFBC is a secure and highly efficient lightweight cryptographic solution.
• The design meets NIST requirements for data, key, and nonce sizes.
• NFBC offers a practical and deployable option for securing constrained devices.
• The combination of NFSR, chaotic S-boxes, and GRP provides a robust security-efficiency balance.