REISSUE OF CRYPTOGRAPHIC CREDENTIALS

摘要

Effecting reissue in a data processing system of a cryptographic credential certifying a set of attributes, the credential being initially bound to a first secret key stored in a first processing device. A backup token is produced using the first device and comprises a commitment to said set of attributes and proof data permitting verification that the set of attributes in said commitment corresponds to the set of attributes certified by said credential. At a second processing device, a second secret key is stored and blinded to produce a blinded key. A credential template token produced from the backup token and the blinded key is sent to a credential issuer where said verification is performed using the proof data and the credential template token is used to provide a reissued credential, certifying said set of attributes, to the second device, the reissued credential being bound to the second secret key.

主权项

1. A method for effecting reissue of a cryptographic credential certifying a set of attributes, the credential being initially bound to a first secret key stored in a first tamper-resistant processing device, the method comprising:
producing a backup token using the first tamper-resistant processing device, the backup token comprising a commitment to said set of attributes and first proof data permitting verification that the set of attributes in said commitment corresponds to the set of attributes certified by said credential; storing the backup token in backup memory; receiving, from a second tamper-resistant processing device storing a second secret key, a blinded key, the blinded key produced by the second tamper-resistant device by blinding the second secret key; producing a credential template token comprising the backup token and the blinded key; sending the credential template token to a credential issuer; receiving, from the credential issuer, a pre-credential, the pre-credential generated by the credential issuer in response to the credential issuer verifying the credential template token, the pre-credential generated using information in the credential template token; and sending the pre-credential to the second tamper-resistant device, wherein the second tamper-resistant device is configured to complete the pre-credential to produce a reissued credential, the reissued credential bound to the second secret key.