Method of authenticating a signature on a work document in which a remote server generates a digital work fingerprint and a representation file of the work document. The representation file and the digital work fingerprint are transmitted to a client station from the remote server via a wide area communication network, and at least one digital representation fingerprint of the representation file is generated. A file to be signed is generated containing at least the digital work and representation fingerprints. The client station generates only one client signature from the file to be signed, and a client signature file is generated containing at least the file to be signed and the client signature.