Abstract: A method and system for key certification in a public key infrastructure. The infrastructure has a network formed of a plurality of nodes. Each node has a private and public key pair. The nodes are either or both a certifying node and a certified node. A certifying node provides a digital certificate referring to the public key of a certified node. The digital certificate is signed by the private key of the certifying node. The method includes providing a root public key for a user, the root public key being at any node in the network chosen by the user, and providing a chain of digital certificates from the node with the root public key across the node network to any other node.

Abstract: A method for processing road use data. A first moving vehicle has an encounter with vehicles in motion. An apparatus in the first vehicle generates and stores encounter records for the encounters. Each encounter record includes a location of the first moving vehicle and a location and identifier of a corresponding vehicle in motion, and is stored in the apparatus. A first encounter record for an encounter between the first moving vehicle and a second moving vehicle is sent by the first moving vehicle to a charging system of a road use charging authority having a data store. If the charging system determines that the data store includes a second encounter record of the encounter received from the second moving vehicle, then the second encounter record is not used in a charging process and/or is deleted from the data store; otherwise, the first encounter record is stored in the data store.

Abstract: A method and system for supply of data relating to a described entity (302) to a relying entity (304). The method includes generating a first digital certificate referred to as an empowerment certificate signed with an electronic signature by a first signing entity. The empowerment certificate includes one or more attributes of the described entity (302) and one or more attributes of the empowerment certificate including one or more attributes identifying the first signing entity. The empowerment certificate also includes an indication of data relating to the described entity (302) which is to be supplied and an indication of one or more sources (306) for the data to be supplied. The empowerment certificate also includes one or more attributes identifying one or more relying entities (304) to which the data is authorised to be supplied.