A computer implemented method for the protection of the integrity and authorship of a piece of registration information belonging to a user, which can be used for a registration of said user as a voter, said method comprising for each piece of registration information the following stages: a) entering, by the user, the registration information in a registration module of at least one computer device; b) generating, by the registration module, an item of integrity proof of the registration information from at least said registration information, wherein the item of integrity proof is generated by means of at least one of: a hash function applied to at least part of the registration information, a MAC function applied to at least part of the registration information using a key known by the user and/or the registrar, and/or from a complete or partial copy of the registration information, said method further comprising: c) displaying, by the registration module, the item of integrity proof to the user in a legible, audible or printable format; d) capturing, by a validation module of at least one computer device, an item of multiformat biometric proof, including voice, an image, writing or a combination thereof, of the user, said item of multiformat biometric proof being captured by obtaining a biometric registration of the user which contains the displayed item of integrity proof including an audio registration, a handwritten registration, a visual registration or a combination thereof; e) generating, by the validation module, an item of non-repudiation proof of the registration information using at least the captured item of multiformat biometric proof; and f) storing, by the validation module, at least the item of non-repudiation proof, wherein either before or after said storing of the item of non-repudiation proof the method: - validates the generated item of non-repudiation proof by verifying if the item of non-repudiation proof has been generated based on an item of integrity proof of any piece of registration information entered; or - validates that the generated item of non-repudiation proof is not a duplicated item of non-repudiation proof by verifying if there is a stored non-repudiation proof which has been generated by the same user as another non-repudiation proof to be stored or already stored but different from the compared one; or - verifies the existence of non-validated registrations of the item of non-repudiation proof by detecting registration information entered in a registration module of at least one computer device for which an item of non-repudiation proof has not yet been stored. a) entering, by the user, the registration information in a registration module of at least one computer device; b) generating, by the registration module, an item of integrity proof of the registration information from at least said registration information, wherein the item of integrity proof is generated by means of at least one of: a hash function applied to at least part of the registration information, a MAC function applied to at least part of the registration information using a key known by the user and/or the registrar, and/or from a complete or partial copy of the registration information, said method further comprising: c) displaying, by the registration module, the item of integrity proof to the user in a legible, audible or printable format; d) capturing, by a validation module of at least one computer device, an item of multiformat biometric proof, including voice, an image, writing or a combination thereof, of the user, said item of multiformat biometric proof being captured by obtaining a biometric registration of the user which contains the displayed item of integrity proof including an audio registration, a handwritten registration, a visual registration or a combination thereof; e) generating, by the validation module, an item of non-repudiation proof of the registration information using at least the captured item of multiformat biometric proof; and f) storing, by the validation module, at least the item of non-repudiation proof, - validates the generated item of non-repudiation proof by verifying if the item of non-repudiation proof has been generated based on an item of integrity proof of any piece of registration information entered; or - validates that the generated item of non-repudiation proof is not a duplicated item of non-repudiation proof by verifying if there is a stored non-repudiation proof which has been generated by the same user as another non-repudiation proof to be stored or already stored but different from the compared one; or - verifies the existence of non-validated registrations of the item of non-repudiation proof by detecting registration information entered in a registration module of at least one computer device for which an item of non-repudiation proof has not yet been stored.