Abstract: To revoke a digital certificate (160p), activation of the digital certificate is blocked by withholding an activation code from the certificate user (110). The certificates are generated by a plurality of entities (210, 220, 838) in a robust process that preserves user privacy (e.g. anonymity) even in case of collusion of some of the entities. The process is suitable for connected vehicles, e.g. as an improvement for Security Credential Management System (SCMS).

Abstract: Methods and apparatus for encrypting and storing data. The methods and apparatus provide different levels of security and usability. The methods and apparatus generate two or more keys based on a shared secret made available to a user equipment and a server. The two or more keys comprise at least one perfect forward secrecy key, and at least one limited forward secrecy key. The methods and apparatus encrypt data using at least one of the two or more keys. The methods and apparatus store the encrypted data in a memory of the user equipment and/or transmit the data from the user equipment to the server.

Abstract: Method and Apparatus for Securing a Connection in a Communications Network A method of operating a user equipment (UE) using a Generic Bootstrapping Architecture (GBA) is provided. The method includes establishing a shared secret between the UE and a Network Application Function (NAF). An authentication request is sent to a Bootstrapping Server Function (BSF) by the UE. An original parameter intended for a key derivation function and a bootstrapping transaction identifier is received from the BSF. An application request, including the bootstrapping transaction identifier, is sent by the UE to the NAF. A modified parameter is derived by the UE from the secret and the original parameter intended for the key derivation function. A cryptographic key is determined using said modified parameter in place of or in addition to the original parameter in the key derivation function, and communications with the NAF are secured using the key.

Abstract: Methods and apparatus for encrypting and storing data. The methods and apparatus provide different levels of security and usability. The methods and apparatus generate two or more keys based on a shared secret made available to a user equipment and a server. The two or more keys comprise at least one perfect forward secrecy key, and at least one limited forward secrecy key. The methods and apparatus encrypt data using at least one of the two or more keys. The methods and apparatus store the encrypted data in a memory of the user equipment and/or transmit the data from the user equipment to the server.

Abstract: A method of securing a session between a Network Application Function, NAF, and a User Equipment, UE, connected to a network. The NAF is assigned a NAF identifier, NAF_id, using the Generic Bootstrapping Architecture, GBA, or a similar architecture and a shared secret is established between the UE and the NAF (S7.1). An application request containing a bootstrapping transaction identifier is sent to the NAF from the UE (S7.2) and an authentication request comprising the bootstrapping transaction identifier, the NAF_id, and information derived from the shared secret is sent to a Bootstrapping Server Function, BSF, from the NAF (S7.4). The BSF and the UE determine a NAF key, Ks_NAF, by using a modified parameter in place of or in addition to an original parameter in a key derivation function, the modified parameter being derived from the shared secret and the original parameter of the key derivation function (S7.5). This NAF key is transmitted from the BSF to the NAF (S7.

Abstract: A method for preserving privacy during authorization in pervasive environments is described. The method includes an authorization phase in which the user is provided with a reusable credential associated with verifiable constraints, and an operation phase where the service provider verifies the reusable credential before authorizing the user. Third parties cannot link plural uses of the credential to each other, and the service provider cannot link plural uses of said credential to each other.

Abstract: A method of controlling access to content comprises receiving, at a domain gateway (3) of a domain (4), a request from a device (5) in the domain for access to the content. It is determined at the domain gateway whether the number of devices in the domain currently accessing the content is equal to a specified maximum number of devices that may simultaneously access the content. The maximum number of devices that may simultaneously access the content is independent of the number of devices in the domain. If the determination is that the number of devices in the domain currently accessing the content is less than the specified maximum number the request is allowed, otherwise it is refused.

Abstract: A method for preserving privacy during authorisation in pervasive environments is described. The method includes an authorisation phase in which the user is provided with a reusable credential associated with verifiable constraints, and an operation phase where the service provider verifies the reusable credential before authorising the user. Third parties cannot link plural uses of the credential to each other, and the service provider cannot link plural uses of said credential to each other.

Abstract: The present invention relates to a method of key management and to an apparatus (200) of communication network (100) comprising a plurality of groups (141, 142, 143), each group (141) including one or several members (132A, 132B, 132C) authorized to have access to key-protected services provided by the apparatus. According to the method, it is determined when a member (132A) starts a switching action from one service to another and it is determined a time dependent quantity starting from the switching action. The method further comprises, determining that the member (132A) is a member of a switching group (150) when the quantity is less than a threshold value, and when the quantity is larger than the threshold, determining that the member (132A) has decided to join a new group (142), and changing the appropriate access key(s).

Abstract: A method of controlling access to content comprises receiving, at a domain gateway (3) of a domain (4), a request from a device (5) in the domain for access to the content. It is determined at the domain gateway whether the number of devices in the domain currently accessing the content is equal to a specified maximum number of devices that may simultaneously access the content. The maximum number of devices that may simultaneously access the content is independent of the number of devices in the domain. If the determination is that the number of devices in the domain currently accessing the content is less than the specified maximum number the request is allowed, otherwise it is refused.