Electronic watermark system electronic information distribution system and image filing apparatus
AssigneeCanon Kabushiki Kaisha
InventorKeiichi Iwamura
Life of this patent
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Abstract
Disclosed is an electronic watermark method, used for a network, comprising a plurality of entities, wherein provided weparately are an entity for embedding an electronic watermark in encrypted data that are exchanged by said plurality of entities, and an entity for performing an encryption process and a corresponding decryption process.
Claims9
An electronic watermark method used for a network system that includes a plurality of entities, wherein for the exchange of digital information by at least a first entity and a second entity of the plurality of entities,
- the first entity embeds an electronic watermark in the digital information, performs a first encryption process for the digital information, and transmits the resultant digital information to the second entity,
- the second entity embeds a second electronic watermark in the digital information received from the first entity, performs a second encryption process for the digital information, obtains a value by transforming the resultant digital information using a one-way compression function, and transmits the value and the resultant digital information to the first entity, and
- the first entity converts the digital information received from the second entity using the one-way compression function and, in accordance with whether the thus obtained value matches the value received from the second entity, performs a first decoding process related to the first encryption process for the digital information.
An electronic watermark system for a network system that includes a plurality of entities, wherein for the exchange of digital information by at least a first entity and a second entity of the plurality of entities,
- the first entity embeds an electronic watermark in the digital information, performs a first encryption process for the digital information, and transmits the resultant digital information to the second entity,
- the second entity embeds a second electronic watermark in the digital information received from the first entity, performs a second encryption process for the digital information, obtains a value by transforming the resultant digital information using a one-way compression function, and transmits the value and the resultant digital information to the first entity, and
- the first entity converts the digital information received from the second entity using the one-way compression function and, in accordance with whether the thus obtained value matches the value received from the second entity, performs a first decoding process related to the first encryption process for the digital information.
A computer-readable medium containing program codes for an electronic watermark method for a network system that includes a plurality of entities, wherein for the exchange of digital information by at least a first entity and a second entity of the plurality of entities,
- the first entity embeds an electronic watermark in the digital information, performs a first encryption process for the digital information, and transmits the resultant digital information to the second entity,
- the second entity embeds a second electronic watermark in the digital information received from the first entity, performs a second encryption process for the digital information, obtains a value by transforming the resultant digital information using a one-way compression function, and transmits the value and the resultant digital information to the first entity, and
- the first entity converts the digital information received from the second entity using the one-way compression function and, in accordance with whether the thus obtained value matches the value received from the second entity, performs a first decoding process related to the first encryption process for the digital information.
A computer-readable program comprising program codes for an electronic watermark method for a network system that includes a plurality of entities, wherein for the exchange of digital information by at least a first entity and a second entity of the plurality of entities,
- the first entity embeds an electronic watermark in the digital information, performs a first encryption process for the digital information, and transmits the resultant digital information to the second entity,
- the second entity embeds a second electronic watermark in the digital information received from the first entity, performs a second encryption process for the digital information, obtains a value by transforming the resultant digital information using a one-way compression function, and transmits the value and the resultant digital information to the first entity, and
- the first entity converts the digital information received from the second entity using the one-way compression function and, in accordance with whether the thus obtained value matches the value received from the second entity, performs a first decoding process related to the first encryption process for the digital information.
Dependencies are inferred from the claim text.