Symmetric cryptographic algorithm based on polarization identity and implementation on file encryption

A good encryption algorithm should provide data pro tection of high quality with high complexity, not dependent on the secrecy of algorithm, implemented economically and effectively and used widely. Symmetric cryptographic algorithm based on polarization identity conducts polarization operation on vectors and inner product decomposition on a constant according to the feature of vector´s inner product, which can provide a certain computational complexity and st rong security by way of the combination of a set of keys. The application of the algorithm on various types of file encryption proves to be easy, flexible and effective.