The authentication process comprises: a step of transferring a holographic matrix onto a base, a step of marking the holographic matrix by laser shot, in order to produce a digital code that cannot be interpreted by the human eye preserving the optical diffraction properties of the holographic matrix, and designed to enable the detection of a copy of a document realized using the holographic matrix. Preferentially, during the marking step, the impact of each laser shot presents a greater dimension and a depth allowing the hologram's optical diffraction properties to be preserved.