Secure document workflow

A method, for a second participant in a secure document workflow, of authenticating a document image, the method comprising:

• receiving the document image from a first workflow participant;
• receiving workflow information relating to the document image, including:
• a document image descriptor, dependent upon the appearance of the document image for verifying the authenticity of a version of the document image that has been printed and scanned, and
• a first digital signature generated by the first participant, derived from at least the document image descriptor;
• verifying the authenticity of the image descriptor, wherein the verification comprises verifying the digital signature;
• and
• verifying the integrity of the received document image, wherein the verification comprises electronically comparing or combining the received document image with the verified image descriptor.

A computer program product for a first participant in a secure document workflow to generate workflow information for authenticating a document, the computer program product comprising:

• a non-transitory computer readable storage medium comprising computer usable program code embodied therewith, the computer usable program code comprising:
• computer usable program code to, when executed by a processor, receive an image of the document;
• computer usable program code to, when executed by a processor, generate workflow information for the document image, including
• a document image descriptor dependent upon the appearance of the document image for later verifying the integrity of a version of the document image that has been printed and scanned, the verification comprising electronically combining or comparing the document image descriptor with said version of the document image;
• computer usable program code to, when executed by a processor, generate a digital signature for later verifying the authenticity of the workflow information, the digital signature being derived from the workflow information using a cryptographic key associated with the first participant;
• computer usable program code to, when executed by a processor, add the digital signature to the workflow information;
• and
• computer usable program code to, when executed by a processor, communicate the document image and the workflow information to another workflow participant.

A computer program product for a first participant in a secure document workflow to generate workflow information for authenticating a document, the computer program product comprising:

• a non-transitory computer readable storage medium comprising computer usable program code embodied therewith, the computer usable program code comprising:
• computer usable program code to, when executed by a processor, receive an image of the document;
• computer usable program code to, when executed by a processor, generate workflow information for the document image, including
• a document image descriptor dependent upon the appearance of the document image for later verifying the integrity of a version of the document image that has been printed and scanned, the verification comprising electronically combining or comparing the document image descriptor with said version of the document image;
• computer usable program code to, when executed by a processor, generate a digital signature for later verifying the authenticity of the workflow information, the digital signature being derived from the workflow information using a cryptographic key associated with the first participant;
• computer usable program code to, when executed by a processor, add the digital signature to the workflow information;
• computer usable program code to, when executed by a processor, communicate the document image and the workflow information to another workflow participant;
• computer usable program code to, when executed by a processor, control a printer to print a copy of the document;
• and
• computer usable program code to, when executed by a processor, print a portion of the workflow information in a machine-readable form on the printed copy.

A printer adapted to print documents for a secure document workflow, the printer comprising:

• an input, for receiving the document from a workflow participant;
• an input, for receiving workflow information associated with the document, including:
• an image descriptor, dependent upon the appearance of the document for verifying the integrity of a version of the document that has been printed and scanned, and
• a first digital signature generated by the participant, derived from at least the image descriptor;
• a processor, adapted to
• verify the authenticity of the image descriptor, comprising verifying the first digital signature;
• verify the integrity of the received document, wherein the verification comprises electronically comparing or combining the received document with the verified image descriptor;
• generate a second digital signature for later verifying the authenticity of the workflow information, the digital signature being derived from the workflow information using a cryptographic key associated with the printer;
• and to
• add the digital signature to the workflow information, and
• printing apparatus, controllable by the processor to
• print a copy of the document;
• and
• print at least a portion of the workflow information in a machine-readable form on the printed copy.