Quantum Security Analysis of Reduced-Round Hash Functions in Quantum Computing

Researchers from Kookmin University in Korea perform quantum rebound attacks in block cipher-based hash functions that are faster than generic attacks

Hash functions are widely used in information security, including commitment schemes, zero-knowledge proofs, integrity checks, and blockchain technology. However, a thorough analysis of their quantum security under different quantum computing environments is missing. To this end, researchers performed detailed quantum security analysis of reduced-round block cipher-based (ARIA) hash functions in different significant modes of quantum computing applications. Their analysis helps us understand the security of hash functions, which has significant implications in information security.

Image title: Analyzing the security of reduced-round block cipher-based (ARIA) hash function in quantum computing environments.

Image caption: The need for information security in quantum environments inspired a group of researchers from Republic of Korea to revisit the security of reduced-round block cipher-based ARIA hash functions in various significant modes of quantum computing.

Hash functions (functions that convert a numeric or alphanumeric key to a small practical integer value) have wide applications in the field of information security. These include commitment schemes, zero-knowledge proofs, integrity checks, and blockchain technology. In this context, quantum security of hash functions that can be constructed based on block ciphers is of paramount importance. The uncertainty surrounding the development of quantum computers underscores the importance of analyzing the hash functions by considering various quantum computing environments. However, investigations on quantum security of block cipher-based hash functions are incomplete and require dedicated research to ensure data security.

In this regard, a team of researchers from Kookmin University in Korea, including Professor Jongsung Kim and Dr. Seungjun Baek, a PhD student in financial information security, performed a detailed quantum security analysis of reduced-round block cipher-based hash functions and their applicability under different quantum computing environments.

In a recent article published in the ETRI journal on 08 March 2023, the researchers have detailed their findings. “Our results are valuable in that they provide the first quantum security analysis of the combination of significant modes (Davies-Meyer (DM), Matyas-Meyer-Oseas (MMO), Miyaguchi-Preneel (MP), Hirose, MJH) and a standardized cipher (ARIA) that is important for practical applications of quantum computing,” explains Prof. Kim.

In their work, the researchers revised existing quantum rebound attacks on ARIA-instantiated single block length (SBL) hash functions. In addition, they developed new quantum rebound attacks on several ARIA-instantiated double block length (DBL) hash functions. Further, the researchers successfully mounted differential trails for five-round ARIA for SBL hash functions (DM, MMO and MP) and seven-round ARIA-256 DBL hash functions (Hirose and MJH).

“If vulnerabilities in hash functions continue to be exposed through related research, the security margin will decrease, potentially rendering them unusable in a quantum computing environment. Additionally, there will be a need to develop hash function designs that are secure in quantum computing environments,” remarks Dr. Baek.

Quantum security analysis of hash functions can catalyze further related research. This is because the message space that an attacker can choose is virtually infinite compared to general block ciphers. Additionally, the findings of the researcher duo’s analysis could motivate researchers to investigate the potential weaknesses and vulnerabilities of the hash function, and study the possibility of finding quantum collisions that can have significant implications for the security of digital systems in the future.

“While our research focuses on reduced-round block cipher-based hash functions, quantum analysis on hash functions is even extending to dedicated hash functions, e.g., SHA-2 and SHA-3. Moreover, if the full round security is broken through sustained dedicated attacks on hash functions, it may be necessary to force the use of alternative ciphers,” notes an optimistic Prof. Kim.

Together, these results will lead us to a better understanding of the hash function security in different quantum computing environments.

Reference

Titles of original papers: Quantum rebound attacks on reduced-round ARIA-based hash functions

DOI: 10.4218/etrij.2022–0032

Name of author: Seungjun Baek1 and Jongsung Kim1,2

Affiliation: 1Department of Financial Information Security, Kookmin University, Seoul, Republic of Korea

2Department of Information Security, Cryptology, and Mathematics, Kookmin University, Seoul, Republic of Korea

About Professor Jongsung Kim

Jongsung Kim received his BS and MS degrees in Mathematics from Korea University, Republic of Korea, in 2000 and 2002, respectively, and received double PhD degrees in 2006 and 2007 at the ESAT/COSIC group of Katholieke Universiteit Leuven, Belgium and at Engineering in Information Security of Korea University, respectively. He is currently a Full Professor in the Department of Information Security, Cryptology and Mathematics and the Department of Financial Information Security at Kookmin University, Republic of Korea. His research interests include cryptanalysis, symmetric cryptosystems, and digital forensics.

About Seungjun Baek

Seungjun Baek received a BS degree in mathematics and an MS degree in financial information security from Kookmin University, Seoul, Republic of Korea, in 2019 and 2022, respectively, where he is currently pursuing a PhD degree in financial information security. His research interests include cryptanalysis, symmetric cryptosystems, quantum algorithms, and digital forensics.