Modeling Polymorphic Ciphers

Abstract

Polymorphic ciphers are a relatively new construct in the field of encryption. Although the first real example of the encryption, the One Time Pad (OTP), has been known since the early part of the 20th century, the idea of a “mutating cipher” has not been implemented and well studied until now. Since these ciphers are actually “engines” comprised of single algorithm ciphers with good encryption properties, such as a large key space, evaluating the characteristics of the engine becomes im-portant. In this paper, we present a simple method to classify the polymorphic properties of ciphers and the polymorphic engine. In addition, the security of such engines is presented, along with an analysis of the additional latency and overhead costs.