| 摘要 |
Methods and apparatus are provided for 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 tamper-resistant processing device (10). A backup token is produced using the first tamper-resistant processing device (10). The backup token comprises 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. The backup token is stored in backup memory (14). If the first tamper-resistant device should be lost or stolen, then at a second tamper- resistant processing device (10) storing a second secret key, the second secret key is blinded to produce a blinded key. A credential template token is produced from the backup token and the blinded key. The credential template token is sent to a credential issuer (2) of the data processing system (1) via user apparatus (6) of the system. At the credential issuer (2), said verification is performed using the first proof data and the credential template token is used to provide a reissued credential, certifying said set of attributes, to the second tamper-resistant device via said user apparatus (6), the reissued credential being bound to the second secret key. |
