Yazarlar

  • MakaleAçık Erişim2022Scopus SJRQ1
    A method for generation of substitution box based on random selection

    Artuğer, Fırat; Özkaynak, Fatih

    Two basic requirements must be met to encrypt data. These requirements are confusion and diffusion properties. In particular, block cipher algorithms are based on a cryptographic component known as substitution-box to provide the need for confusion. Therefore, attack scenarios generally focus on this cryptographic component. There are alternative design approaches for substitution-box design. It is known that each design approach has several advantages and disadvantages. In this study, an alternative method is proposed to address the problems of the substitution-box design approach based on random selection. The success of the proposed method has been tested in three different scenarios. Analysis results for these three scenarios showed that generated substitution-box provides performance increase for nonlinearity criterion from s-box design criteria. Successful results achieved; It points out that improvement cryptographic components can be used in a variety of practical applications such as block ciphers, masks to prevent side-channel attacks, random number generators, and image encryption algorithms.

    AtıfScopus29WoS25OpenAlex35
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2021Scopus SJRQ1
    An effective method to improve nonlinearity value of substitution boxes based on random selection

    Artuğer, Fırat; Özkaynak, Fatih

    In today's digital society, new design alternatives are needed for substitution box structures, which has critical importance in developing secure information systems that are resistant to algebraic and application attacks, as new attacks negatively affect designs based on mathematical transformations. Although random selection-based substitution box structures are a good alternative against algebraic and application attacks, the low value of nonlinearity criterion is an important problem. Solution suggestions using optimization algorithms have been proposed to address this problem. “Information Sciences 523 (2020) 152–166” is the study that reached the highest nonlinearity value based on optimization algorithms to date. However, the high computational costs of optimization algorithms are another challenge that must be overcome. In this study, it has been shown that the nonlinearity values ​​of random (chaotic) selection substitution box structures can be improved as much as mathematically based designs by using a method that is too simple to compare with optimization algorithms. It has been shown that the nonlinearity value can be improved up to 110 for random selection-based substitution box designs. Although this nonlinearity value is the highest achievable value in the literature based on the random selection principle, the fact that it requires only 2×255×255 processes in the worst case has been evaluated as an important success of the proposed method compared to other design approaches. Other advantages of the proposed method are that the improved substitution box structures are resistant to side-channel attacks, simple structure, easy hardware implementation, and successful results in practical applications such as image encryption. It is believed that all these results will be a motivation for new post-processing techniques to be designed in the future for random selection-based substitution box designs.

    AtıfScopus42WoS30OpenAlex42
    ScopusWeb of Scienceİncele