1. A method of validating the authenticity of a signature on a document, the method comprising the steps of: creating a fingerprint comprising machine-readable data corresponding to authorized account signatures, the fingerprint comprising a one-dimensional skeletonized version of account signature data, wherein the fingerprint contains 500 bytes of information or less; providing a document from an account, the document including an actual signature and a fingerprint; presenting the document at a point of presentment; scanning the document, including the actual signature and the fingerprint, into a document-processing machine; and comparing the actual signature against the account signature data in the fingerprint.