Abstract: An identity confirmation device comprises a token issuer 4 and an authentication device 5, the token issuer being programmable by a central identity provider 2 to issue certification tokens for use in e-commerce whereby transactions can be certified with suppliers without need for additional communication with a central server.

Abstract: In a transaction authorisation arrangement a sales point (1) (an electronic point of sale device or a vending machine, for example) communicates with a transaction application (2) transmitting thereto a transaction value. The telephony platform (3) reserves one of a series of premium rate numbers (5) which can be dialled up by a mobile telephone user to authorise the charging of the transaction against the telephone bill. When a call is received at the premium rate number the telephony platform notifies the transaction application which then authorises the sale.

Abstract: Security check method and apparatus reduces problems that can arise if the user security data set becomes known by unauthorized persons. To address this problem only part of the user data set is recorded in insecure sections of the system. For example, a security check preventing unauthorized remote access to a shared computer is provided by capturing a user data set representing a user's iris, operating the user's personal computer to select only a portion of the captured data set requested by the shared computer and transmitting the portion along a telecommunications line. The shared computer derives partial data sets from stored user data sets using a similar selection to that used by personal computer and compares the partial data set it has derived with the partial data set transmitted by the personal computer in deciding whether to grant access. Point-of-sale devices and cards recording only partial user data sets are also disclosed.