The present invention relates to a method for a secure execution of a whitebox cryptographic algorithm applied to a message (m) and protected by countermeasures based on pseudo-random values, comprising the steps of: executing a pseudo-random function (PRP) generating pseudo-random output values and an encrypted main output value based on an encrypted input value (*Xi*) derived from said message, securing said cryptographic algorithm by applying to the cryptographic algorithm said countermeasures based on said generated pseudo-random output values retrieving, from said generated encrypted main output value, the input value or part of the input value, under an encrypted form (*Xi*), executing said secured cryptographic algorithm on said encrypted retrieved value.