Decorrelation theory

According to Vaudenay, the decorrelation theory has four tasks: 1) the definition of a measurement for the decorrelation, which usually relies on a matrix norm; 2) the construction of simple primitive or "decorrelation module" with a quite good decorrelation; 3) the construction of cryptographic algorithms with decorrelation modules so that the primitive can be inherited by the algorithm; and, 4) proving that the decorrelation provides security against attacks.