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US 8,078,878 B2Granted
Securing documents with electronic signatures
AssigneeSap SE
InventorJosef Dietl
Life of this patent
Estimating the term…
Abstract
Methods, apparatus, including computer program products, and systems implement and use techniques relating to electronic signatures. In one implementation, a one-way hash is calculated for an electronic document and a digital watermark representing the one-way hash is embedded in a signature document. Based on a user input, the signature document having the embedded digital watermark is altered, and the electronic document is associated with the signature document. The electronic document and the signature document together comprise a signed electronic document. The user input can include biometric information, such as a handwritten signature or a voice recording. For additional security, the one-way hash can be encrypted before a representation of the hash is embedded in the signature document.
Claims24
A computer-implemented method comprising:
- in response to at least a selection through a portable signing device by an employee of a courier service, presenting an electronic document through the portable signing device to a signer, the electronic document assigned to an item being delivered to the signer and configured to indicate receipt of the item by the signer, the portable signing device managed by the courier service different than the signer of the electronic document and configured to receive signatures from different signers;
- calculating a one-way hash for the electronic document;
- encrypting, using the portable signing device, the one-way hash using a private key assigned to the portable signing device different from private keys assigned to signers and inaccessible to signers, the portable device configured to encrypt, using the portable-device private key, one-way hashes for documents signed by other signers, a public-private key certificate of the private key is maintained by the courier service and inaccessible to the signers;
- embedding a digital watermark representing the encrypted one-way hash in a signature document, wherein the digital watermark is a second image representing a watermark that overlays at least a portion of a first image and embeds in the signature document the encrypted one-way hash calculated using the electronic document;
- based on input from the signer of the electronic document, altering an appearance of the signature document having the embedded digital watermark;
- and
- associating the electronic document with the signature document, wherein the electronic document and the signature document together comprise a signed electronic document.
4 more elements
A system comprising:
- one or more processors configured to:
- in response to at least a selection through a portable signing device by an employee of a courier service, present an electronic document through the portable signing device to a signer, the electronic document assigned to an item being delivered to the signer and configured to indicate receipt of the item by the signer, the portable signing device managed by the courier service different than the signer of the electronic document and configured to receive signatures from different signers;
- calculate a one-way hash for the electronic document;
- encrypt, using the portable signing device, the one-way hash using a private key assigned to the portable signing device different from private keys assigned to signers and inaccessible to signers, the portable device configured to encrypt, using the portable-device private key, one-way hashes for documents signed by other signers, a public-private key certificate of the private key is maintained by the courier service and inaccessible to the signers;
- embed a digital watermark representing the encrypted one-way hash in a signature document, wherein the digital watermark is a second image representing a watermark that overlays at least a portion of a first image and embeds in the signature document the encrypted one-way hash calculated using the electronic document;
- based on input from the signer of the electronic document, alter an appearance of the signature document having the embedded digital watermark;
- and
- associate the electronic document with the signature document, wherein the electronic document and the signature document together comprise a signed electronic document;
- and
- a user interface configured to receive the user input.
7 more elements
A computer-implemented method comprising:
- in response to at least a selection through a portable signing device by an employee of a courier service, presenting an electronic document through the portable signing device to a signer, the electronic document assigned to an item being delivered to the signer and configured to indicate receipt of the item by the signer, the portable signing device managed by the courier service different than the signer of the electronic document and configured to receive signatures from different signers;
- calculating a one-way hash for the electronic document;
- encrypting, using the portable signing device, the one-way hash using a private key assigned to the portable signing device different from private keys assigned to signers and inaccessible to signers, the portable device configured to encrypt, using the portable-device private key, one-way hashes for documents signed by other signers, a public-private key certificate of the private key is maintained by the courier service and inaccessible to the signers;
- embedding a digital watermark representing the encrypted one-way hash in an audio signature file, wherein the digital watermark is a second image representing a watermark that overlays at least a portion of a first image and embeds in the signature document a first one-way hash calculated using the electronic document;
- based on input from the signer of the electronic document, altering a sound of the audio signature file having the embedded digital watermark;
- and
- associating the electronic document with the audio signature file, wherein the electronic document and the audio signature file together comprise a signed electronic document.
4 more elements
A computer program product, tangibly stored on a computer-readable medium, comprising instructions operable to cause a programmable processor to:
- in response to at least a selection through a portable signing device by an employee of a courier service, present an electronic document through the portable signing device to a signer, the electronic document assigned to an item being delivered to the signer and configured to indicate receipt of the item by the signer, the portable signing device managed by the courier service different than the signer of the electronic document and configured to receive signatures from different signers;
- calculate a one-way hash for the electronic document;
- encrypt, using the portable signing device, the one-way hash using a private key assigned to the portable signing device different from private keys assigned to signers and inaccessible to signers, the portable device configured to encrypt, using the portable-device private key, one-way hashes for documents signed by other signers, a public-private key certificate of the private key is maintained by the courier service and inaccessible to the signers;
- embed a digital watermark representing the encrypted one-way hash in a signature document, wherein the digital watermark is a second image representing a watermark that overlays at least a portion of a first image and embeds in the signature document a first one-way hash calculated using the electronic document;
- based on input from the signer of the electronic document, alter an appearance of the signature document having the embedded digital watermark;
- and
- associate the electronic document with the signature document, wherein the electronic document and the signature document together comprise a signed electronic document.
4 more elements
A computer program product, tangibly stored on a computer-readable medium, comprising instructions operable to cause a programmable processor to:
- in response to at least a selection through a portable signing device by an employee of a courier service, present an electronic document through the portable signing device to a signer, the electronic document assigned to an item being delivered to the signer and configured to indicate receipt of the item by the signer, the portable signing device managed by the courier service different than the signer of the electronic document and configured to receive signatures from different signers;
- calculate a one-way hash for the electronic document;
- encrypt, using the portable signing device, the one-way hash using a private key assigned to the portable signing device different from private keys assigned to signers and inaccessible to signers, the portable device configured to encrypt, using the portable-device private key, one-way hashes for documents signed by other signers, a public-private key certificate of the private key is maintained by the courier service and inaccessible to the signers;
- embed a digital watermark representing the encrypted one-way hash in an audio signature file, wherein the digital watermark is a second image representing a watermark that overlays at least a portion of a first image and embeds in the signature document a first one-way hash calculated using the electronic document;
- based on input from the signer of the electronic document, alter a sound of the audio signature file having the embedded digital watermark;
- and
- associate the electronic document with the audio signature file, wherein the electronic document and the audio signature file together comprise a signed electronic document.
4 more elements
Dependencies are inferred from the claim text.