Abstract: A method for obtaining at least one securitized cleartext attestation by at least one requestor subject coupled to a data processing system and communicating with each other through a network. The data processing system includes a plurality of subjects and an authority represented by at least one server acting on behalf of the authority and issuing attestations. The requestor subject sends the authority an attestation request including at least one protection datum. The requestor subject chooses, at random, a check datum which is associated and linked with the protection datum. The requestor subject then transmits, in cleartext, to the authority both a piece of identification information defining the relationship between the check datum and the protection datum, and the protection datum itself. The server organizes the attestation in the form of binary information and calculates at least one of a signature and a seal of attestation taking into account the protection datum and the identification information.