Internal and External Re-keying and the way forward

Approved

Relevance and Originality:

This research article addresses a pressing and long-standing challenge in the field of cryptographic hardware security: Side Channel Analysis (SCA), particularly power analysis attacks. Its relevance stems from the fact that such attacks can bypass the inherent mathematical robustness of cryptographic algorithms by exploiting flaws in their physical implementation. The article’s focus on rekeying, especially distinguishing between internal and external rekeying methods, introduces a relatively underexplored area. By identifying that no consolidated literature exists comparing both rekeying strategies in depth, the work positions itself as a novel contribution and fills a meaningful research gap in the ongoing efforts to harden devices against SPA, DPA, CPA, and related attacks.

Methodology:

The article employs a literature survey methodology, effectively synthesizing a wide range of prior studies on power analysis and associated countermeasures like masking and rekeying. The classification of attacks and their corresponding defenses is clearly presented, offering a comprehensive theoretical foundation. However, the survey could be strengthened by introducing a structured comparison framework—such as benchmarking criteria for performance, scalability, and overhead—for internal vs. external rekeying techniques. The absence of practical case studies or simulations limits the technical depth, but the methodological approach is otherwise appropriate for a survey-type work aimed at establishing future research directions.

Validity & Reliability:

The conclusions drawn are well-aligned with established research trends and accurately reflect the strengths and limitations of existing countermeasures like masking. The article convincingly argues the growing need for efficient alternatives like rekeying due to the overhead and implementation complexity of masking. Nonetheless, because the work is based purely on secondary sources, its findings—while logically coherent—lack empirical substantiation. The reliability of the recommendations would improve with references to concrete performance metrics or comparative evaluations from real-world implementations. Without experimental backing, the generalizability of the proposed insights into rekeying remains theoretical.

Clarity and Structure:

The article is structured in a logical and progressive manner, beginning with foundational knowledge on side-channel attacks and leading into specific discussions on leakage sources and attack typologies. The transition to countermeasure analysis is smooth, and the division of rekeying strategies into internal and external categories is well-articulated. However, there are several grammatical and stylistic errors that detract from readability—for example, phrases like “architectural of the chip manufacturing” and “have been widely implemented countermeasure” require correction. Improving the language and adding visual aids such as diagrams or summary tables would significantly enhance clarity and comprehension.

Result Analysis:

The article provides a balanced and insightful analysis of existing countermeasures, notably identifying the limitations of masking due to high computational overhead. The exploration of rekeying as a scalable and practical alternative is timely and well-reasoned. The distinction between internal and external rekeying, along with a call for further detailed research, sets a constructive agenda for future exploration. The work successfully synthesizes current knowledge while pointing toward unanswered questions, making it a valuable reference for researchers aiming to strengthen resistance to power analysis attacks in cryptographic systems.