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AssigneeInternational Business Machines Corporation
InventorsRosario Gennaro, Paul Ashley Karger, Stephen Michael Matyas, Jr., Mohammad Peyravian, David Robert Safford, Nevenko Zunic
Estimating the term…
A method and apparatus for verifiably providing key recovery information to one or more trustees in a cryptographic communication system having a sender and a receiver Each communicating party has its own Diffie-Hellman key pair comprising a secret value and corresponding public value, as does each trustee The sender non-interactively generates from its own secret value and the public value held by the receiver a first shared Diffie-Hellman key pair comprising a first shared secret value, shared with the receiver but not with any trustee, and a corresponding public value. For each trustee, the sender then non-interactively generates an additional shared secret value, shared with the receiver and the trustee, from the first shared secret value and the public value corresponding to the secret value held by the trustee. The sender uses the additional shared secret value to encrypt recovery information for each trustee, which is transmitted to the receiver along with the encrypted message. Each trustee can decrypt its recovery information by regenerating its additional shared secret value from its own secret value and the public value of the first shared Diffie-Hellman key pair. The receiver can verify the correctness of the recovery information for each trustee by decrypting the information using the additional shared secret value for that trustee, without having to recreate the recovery information or perform computationally expensive public key operations.
In a system in which a sender encrypts data under an encryption key to generate encrypted data and transmits said encrypted data along with recovery information to a receiver via a communications channel, said system having a trustee for enabling the recovery of said encryption key using said recovery information, said sender and said receiver having a first shared secret value that is not shared with said trustee, said trustee holding a secret value from which a corresponding public value is generated, a method for making said recovery information available to said trustee, wherein said sender performs the steps of:
In a system in which a sender encrypts data under an encryption key to generate encrypted data and transmits said encrypted data along with recovery information to a receiver via a communications channels said system having a trustee for enabling the recovery of said encryption key using said recovery information, said sender and said receiver having a first shared secret value that is not shared with said a trustee and a first shared public value generated from said first shared secret value, said trustee holding a secret value from which a corresponding public value is generated, said transmitted recovery information being encrypted using an additional shared secret value generated from said first shared secret value and the public value generated from the secret value held by said trustee, a method for regenerating said recovery information for said receiver, wherein said receiver performs the steps of:
In a system in which a sender encrypts data under an encryption key to generate encrypted data and transmits said encrypted data along with recovery information to a receiver via a communications channel, said system having a trustee for enabling the recovery of said encryption key using said recovery information, said sender and said receiver having a first shared secret value that is not shared with said trustee and a first shared public value generated from said first shared secret value, said trustee holding a secret value from which a corresponding public value is generated, said transmitted recovery information being encrypted using an additional shared secret value generated from said first shared secret value and the public value generated from the secret value held by said trustee, a method for regenerating said recovery information for said trustee, wherein said trustee performs the steps of:
In a system in which a sender encrypts data under an encryption key to generate encrypted data and transmits said encrypted data along with recovery information to a receiver via a communications channel, said system having a trustee for enabling the recovery of said encryption key using said recovery information, said sender and said receiver having a first shared secret value that is not shared with said a trustee, said trustee holding a secret value from which a corresponding public value is generated, apparatus associated with said sender for making said recovery information available to said trustee, comprising:
In a system in which a sender encrypts data under an encryption key to generate encrypted data and transmits said encrypted data along with recovery information to a receiver via a communications channel, said system having a trustee for enabling the recovery of said encryption key using said recovery information, said sender and said receiver having a first shared secret value that is not shared with said trustee and a first shared public value generated from said first shared secret value, said trustee holding a secret value from which a corresponding public value is generated, said transmitted recovery information being encrypted using an additional shared secret value generated from said first shared secret value and the public value generated from the secret value held by said trustee, apparatus within said receiver for regenerating said recovery information for said receiver, comprising:
In a system in which a sender encrypts data under an encryption key to generate encrypted data and transmits said encrypted data along with recovery information to a receiver via a communications channel, said system having a trustee for enabling the recovery of said encryption key using said recovery information, said sender and said receiver having a first shared secret value that is not shared with said trustee and a first shared public value generated from said first shared secret value, said trustee holding a secret value from which a corresponding public value is generated, said transmitted recovery information being encrypted using an additional shared secret value generated from said first shared secret value and the public value generated from the secret value held by said trustee, apparatus associated with said trustee for regenerating said recovery information for said trustee, comprising:
Dependencies are inferred from the claim text.