Algorithm Hopping Symmetric Cryptography

A novel symmetric cryptography technique based on algorithm hopping is proposed in this paper. Traditional cryptography algorithms use a single encryption algorithm to encrypt the entire plain test. The proposed cryptographic system applies different encryption algorithm to encrypt different parts of plaintext. The strength of this cryptography is in hiding the internal parameters of the Cryptography. The parameters hidden are the actual encrypting algorithm that will be used to encrypt the next partof plain text,and the size of the next part that will be encrypted. The method used to determine the hidden parameters uses apseudorandom number. This pseudorandom selection of the next encrypting algorithm is similar to the technique of Frequency Hopping Spread Spectrum which selects the next hopping frequency pseudo-randomly. This pseudorandom number is pre agreed sequence which functions as the private key in the context of cryptography. The proposed method can be applied to several of encryption algorithms. To evaluate the proposed system, a pool of non- exhaustive Boolean functions is chosen as encryption algorithm. In this case, the pseudorandom number determines the next Boolean function that will encrypt the next part of the plain text, and the second parameter.One of the primary advantages of choosing Boolean functions is that, it can be implemented using Binary Decision Diagrams (in software) and Field Programmable Gate Arrays or Application Specific Integrated Circuits (in hardware). Since these Boolean functions are implemented using logic gates, the encryption and decryption speed will be much high compared to traditional encryption algorithms that use intense decimal number system calculations. In future, this algorithm hopping cryptography can also be extended as asymmetric cryptography to support public keys. Keywords - Symmetric Cryptography, Frequency Hopping, Boolean Function, Binary Decision Diagrams, Field Programmable Gate Arrays