7. The system as recited in claim 1 , further comprising: at the certification authority computer system, a policy under which the certification authority generates the digital certificate, said policy communicated with the digital certificate; and at the relying party, using the policy of the certification authority in evaluating whether to trust an identification of the signature authority in the digital certificate.
1. A system for authenticating an electronic document having a digital signing signature enabling a relying party that receives the digitally signed electronic document to evaluate a risk of relying on the digitally signed electronic document, comprising: an electronic network configured for electronic communication among a plurality of communication devices each associated with a respective computer system operated by a certification authority, by a signature authority, and by a signing party; the certification authority computer system configured for generating by the certification authority a digital certificate certifying a cryptographic key pair of a private key and a public key for the signature authority; the signing party computer system configured for directing the signature authority to execute a to be signed electronic document for creating a digitally signed electronic document by generating a signature creation request specifying the to be signed electronic document and communicating the signature creation request through the electronic network to the signature authority computer system; the signature authority computer system having an electronic storage device that stores the private key and the digital certificate communicated by the certification authority through the electronic network to the signature authority computer system for use when constructing an electronic signature for indicating execution of the to be signed electronic document as directed by the signing party to create the digitally signed electronic document; the signature authority computer system configured for obtaining in response to a receipt of the signature creation request, a copy of the to be signed electronic document specified in the signature creation request; the signature authority computer system configured for creating a signature data structure that includes an assertion that the signature authority applies its digital signature to the to be signed electronic document for the purpose of certifying that the signing party has legally signed the to be signed document as directed in the signature creation request, the signature authority, creating the signature data structure and, with the retrieved private key and digital certificate, creating a digital signing signature covering the signature data structure and the to be signed document and resulting in a digitally signed electronic document, whereby a relying party receiving the digitally signed electronic document, relying on the signature data structure, the digital signing signature, and the signature authority digital certificate for verifying the digital signing signature on the signature data structure using the signature authority digital certificate, to evaluate a risk of relying on the digitally signed electronic document.