Method of encryption with dynamic diffusion and confusion layers

A method for the symmetrical encryption of plaintext messages with a secret key, the method implementing at least one substitution layer using a substitution table and a diffusion layer using a diffusion matrix, wherein:

• a counter is initialised with a seed and said counter is incremented at least once between the encryption of two successive plaintext messages;
• a non-invertible transformation is performed on a combination of said secret key with an output word from said counter in order to generate a control parameter;
• the substitution layer and/or the diffusion layer is configured with the control parameter, the configuration of the substitution layer being manifested by an identical permutation of the bits of each element of the substitution table and the configuration of the diffusion layer being manifested by a permutation of the elements of the diffusion matrix.