公开(公告)号：DE112015002927T5

公开(公告)日：2017-03-16

申请号：DE112015002927

申请日：2015-08-25

Applicant: IBM

Inventor： LEHMANN ANJA ,  NEVEN GREGORY ,  CAMENISCH JAN LEONHARD ,  ENDERLEIN ROBERT R ,  KRENN STEPHAN

IPC: H04L9/08 ,  H04L9/32

Abstract: Bereitgestellt werden Verfahren und Vorrichtungen zum Generieren eines geheimen Chiffrierschlüssels eines Benutzercomputers 3, der sich über ein Netzwerk 4 mit einem Server 2 verbinden lässt. Auf dem Benutzercomputer 3 wird ein geheimer Benutzerwert bereitgestellt. Auf dem Server 2 wird ein geheimer Serverwert mit einem Prüfwert bereitgestellt, der den geheimen Benutzerwert und ein Benutzerkennwort codiert. Als Reaktion auf eine Eingabe eines Eingabekennworts auf dem Benutzercomputer 3 codiert der Benutzercomputer den geheimen Benutzerwert und das Eingabekennwort, um einen ersten Wert zu erzeugen, der dem Prüfwert entspricht, und überträgt den ersten Wert über das Netzwerk 4 an den Server 2. Als Reaktion darauf vergleicht der Server 2 den ersten Wert und den Prüfwert, um zu prüfen, ob das Eingabekennwort gleich dem Benutzerkennwort ist. Wenn dies der Fall ist, codiert der Server 2 den ersten Wert und den geheimen Serverwert, um einen zweiten Wert zu erzeugen, und überträgt den zweiten Wert über das Netzwerk 4 an den Benutzercomputer 3. Als Reaktion darauf generiert der Benutzercomputer den geheimen Chiffrierschlüssel, indem er den zweiten Wert, das Eingabekennwort und den geheimen Benutzerwert codiert.

公开(公告)号：GB2530726A

公开(公告)日：2016-04-06

申请号：GB201416888

申请日：2014-09-25

Applicant: IBM

Inventor： CAMENISCH JAN LEONHARD ,  GILAD YOSSI ,  LEHMANN ANJA ,  NAGY ZOLTAN ARNOLD ,  NEVEN GREGORY

IPC: G06F21/41 ,  G06F21/33 ,  H04L9/08 ,  H04L9/32 ,  H04L29/06

Abstract: A user computer (2, fig. 1) connects via a network (3, fig. 1) to verifier servers (4, fig. 1) and authentication servers (5, fig. 1). Respective cryptographic shares of password data, dependent on a predetermined user password, are provided at the authentication servers. A plurality of password data shares is needed to determine if the password matches a password attempt. Respective cryptographic shares of secret data, enabling determination of a username for a verifier server, are provided at the authentication servers. A plurality of secret data shares is needed to reconstruct the secret data. The user computer communicates 32, via the network, with a minimum threshold number of the authentication servers and the password data shares of those servers are used to determine if 33 the user password matches an input password attempt 31. If so, the user computer receives 35 secret data shares from respective authentication servers. On receipt of said shares, the user computer reconstructs 36 and uses the secret data to generate 37, in communication with a plurality of the authentication servers, a cryptographic token for authenticating 38, 39 secretly from the authentication servers the user computer to a selected verifier server under the username that server.

公开(公告)号：GB2527603A

公开(公告)日：2015-12-30

申请号：GB201411510

申请日：2014-06-27

Applicant: IBM

Inventor： CAMENISCH JAN LEONHARD ,  LEHMANN ANJA ,  NEVEN GREGORY ,  KRENN STEPHAN

IPC: H04L9/32

Abstract: Re-issuance of an attribute-based user credential, wherein the user is holding backup values derived from a first credential previously obtained from the issuer, wherein the first credential is built using at least a first value of at least one authentication pair, comprising: receiving by the issuer from the user a set of values derived from the backup values comprising a second value of the at least one authentication pair, validating by the issuer that the second value is a valid authentication answer with respect to the first value and whether the set of values was derived from a valid first credential, and providing by the issuer a second credential to the user based on the first set of values.

公开(公告)号：GB2521802B

公开(公告)日：2015-10-14

申请号：GB201508225

申请日：2013-10-10

Applicant: IBM

Inventor： CAMENISCH JAN L ,  LEHMANN ANJA ,  NEVEN GREGORY

IPC: H04L9/32

Abstract: 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.

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.