公开(公告)号：GB2521802A

公开(公告)日：2015-07-01

申请号：GB201508225

申请日：2013-10-10

Applicant: IBM

Inventor： CAMENISCH JAN L ,  LEHMANN ANJA ,  NEVEN GREGORY

IPC: H04L9/32

Abstract: 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.

公开(公告)号：GB2490075A

公开(公告)日：2012-10-17

申请号：GB201214024

申请日：2011-02-16

Applicant: IBM

Inventor： BICHSEL PATRIK ,  CAMENISCH JAN L ,  GROSS THOMAS R

IPC: G06F21/33 ,  G06F21/55 ,  G06F21/62

Abstract: Data security devices (5) are provided of the type which store user data and can interact with terminal devices (2) to provide information about the stored user data to the terminal devices (2). Such a data security device (5) has memory (10) for storing user data, an interface (7) for transmission of data communications between the security device (5) and a terminal device (2) connectable to a data communications network (3), and a controller (8). The controller (8) processes a request from the terminal device (2) for information about said user data by first generating a message comprising an indication of the information requested about the user data. The message is generated so as to permit verification, using secret data, that the message was generated by the controller (8). The controller sends the message to the terminal device (2) for communication via the network (3) to a publication entity (4) for publication of the message in the network. The controller (8) then receives from the terminal device (2) a cryptographic construction, issued by the publication entity (4), encoding the message published by the publication entity (4). The controller checks validity of the cryptographic construction for said message generated by the controller (8), and subsequent supply of the information requested about the user data to the terminal device (2) is then dependent on said cryptographic construction. Corresponding terminal devices (2) and systems (1) are also provided.