AhnLab researcher wins award at Korea's only cryptanalysis competition

A researcher from AhnLab's threat intelligence unit A-FIRST has won an award at the only cryptanalysis competition held in South Korea, demonstrating the ability to analyze the structure and vulnerabilities of complex cryptographic algorithms and derive decryption techniques.

AhnLab said Wednesday that the REPO team — which includes an A-FIRST researcher — received an encouragement award (Signal Technology Research Institute Director's Award) at the 12th Annual Cryptanalysis Competition 2026. The ceremony was held Sept. 21 at the Nine Tree Premier Locauz Hotel in Yongsan, Seoul.

The Cryptanalysis Competition is the only contest of its kind in South Korea, co-hosted by the Korea Institute of Information Security and Cryptology and the military's 777 Command. Held annually since 2015, this year's competition ran from April through Wednesday. Participants may use past problems and related reference materials to solve the challenges.

Competitors tackled problems across eight categories: classical cryptanalysis, cryptographic implementation, network security, digital forensics, homomorphic encryption, PRNG analysis, integer factorization and block cipher analysis.

Lee Jeong-wook, an A-FIRST researcher who served as the REPO team's leader, received the award alongside teammates Yoon Do-hyeon and Yoon Ju-yeol, both industry and academic security specialists. The team was recognized for identifying the structure of the cryptographic algorithms required for each problem, analyzing their vulnerabilities, and deriving decryption techniques and source code — demonstrating their cryptanalysis and problem-solving capabilities.

Han Chang-gyu, head of AhnLab's research division, said the company's researchers "are broadening their expertise by taking on various technical competitions based on their hands-on experience," adding that AhnLab would "continue to proactively respond to new threats in the AI era, drawing on our accumulated threat analysis capabilities."