The Security Analysis And Research In White-box Cryptography

Since twenty-first century, with the rapid development of computer and network security technology, information security has become an important research topic. Software protection has gained more and more attention. The traditional cryptography is based on the black box model, assumes that the algorithm runs in a trusted environment which can't be checked or changed. According to statistics, more than 80% software is visible to the attacker. It's called White-Box Attack Context-- an attacker can easily obtain key information by observation or perform cryptographic software. Therefore, the concept of white box cryptography emerge as the times require. It contributes to hide key in the implementation of cryptographic information software, and prevent hackers from key in white box attack environment.First of all, the paper makes a brief analysis of white box attack context and white box cryptography. Chow first proposed AES is achieved by introducing a look-up table form design for white box, and then analyze BGE attack technology's success reason. Bringer additional disturbed equations in primitive equation, constructed of white box cryptography. The paper focuses on it's propose algebraic analysis and BEG attack method aiming at Chow's AES white box, ensure to achieve the key in302 minutes.Then, the paper makes comprehensive analysis on the realization method of the above two kind of white box design, comparative advantages and disadvantages of them. Make research on AES algorithm of Xiao.Finally, this paper proposes a new improved white box cryptography algorithm design, which design concept is that, combine drawing on the experience of Chow's white box and the Information chaos technology by Bringer into the implementation of new information, the new and more safety white box cryptography algorithm realized.In work efficiency aspect, it takes about only 5MB space to achieve a complete white box AES improved algorithm, compared with the Chow and Bringer's design of white box cryptography implementation, greatly improving the space occupancy and efficiency.From the security perspective, considering both from a single table lookup mode of attack, Billet attack angle or Mulder attacks, the new one can effectively resist them. Based on this, the white box AES improved realization ensures high level security for all kinds of attack methods.