Published on December 25th, 2017 📆 | 6607 Views ⚑0
[CB17] Key recovery attacks against commercial white-box cryptography implementations
White-box cryptography aims to protect cryptographic primitives and keys in software implementations even when the adversary has a full control to the execution environment and an access to the implementation of the cryptographic algorithm. It combines mathematical transformation with obfuscation techniques so it’s not just obfuscation on a data and a code level but actually algorithmic obfuscation.
In the white-box implementation, cryptographic keys are mathematically transformed so that never revealed in a plain form, even during execution of cryptographic algorithms. With such security in the place, it becomes extremely difficult for attackers to locate, modify, and extract the cryptographic keys. Although all current academic white-box implementations have been practically broken by various attacks including table-decomposition, power analysis attack, and fault injection attacks, There are no published reports of successful attacks against commercial white-box implementations to date. When I have assessed Commercial white box implementations to check if they were vulnerable to previous attacks, I found out that previous attacks failed to retrieve a secret key protected with the commercial white-box implementation. Consequently, I modified side channel attacks to be available in academic literature and succeeded in retrieving a secret key protected with the commercial white-box cryptography implementation. This is the first report that succeeded to recover secret key protected with commercial white-box implementation to the best of my knowledge in this industry. In this talk, I would like to share how to recover the key protected with commercial white-box implementation and present security guides on applying white-box cryptography to services more securely.
I am a senior security engineer currently working in the security department at LINE corp and mostly engaged in security assessment, security architecture design and development. I like to analyze the program and find vulnerabilities in it also, am interested in technology related to security. In recent years, I have been interested in white-box cryptography doing various researches such as implementation, cryptanalysis.