Advanced Concept for Simple Realizable Ciphers
By definition, such ciphers cannot be deciphered without a key.
Main Concept Summary
It is well known in cryptography that it is easy to construct an unbreakable secret-key cipher system if a plaintext source generates letters which are independent and have equal probabilities. Such a system can be easily done even if the length of a key sequence is much less than the message length.
A method for two new key cipher systems has been developed in which a generated message is transformed in such a way that either all letters of the transformed sequence are independent and equiprobable, or the main part of the transformed sequence consists of such symbols.
The first system is based on new algorithms of homophonic coding. The second is based on a new efficient enumerative coding.
The complexity of the proposed algorithms is exponentially less than that for currently existing methods. (Complexity of a method is characterised by two parameters: the time of encoding and decoding (in bit operations) and the memory size in bits).
The length of the key may be less than 1% of the length of encrypted message.
The key may be either secret or calculated on the basis of open key algorithms.
Potential Applications
This development is an ideal cryptosystem for text with known structure (like text in languages like English, French, etc.). It is proven that nobody can break such a system without a key.
|
