The invention relates to a system comprising a first device and a second device, which first device is provided with a first memory means for storing a definition signal, a first generating means for generating a first signal intended for the second device, and which second device is provided with a second memory means for storing the definition signal, and a second generating means for generating, in response to the first signal, the second signal which comprises at least a section of the definition signal stored in the second memory means.
In addition, the first device is provided with first comparison means for comparing at least a section of the second signal originating from the second device with at least a section of the definition signal stored in the first memory means.
Such a system is generally known, and the first device is formed, for example, by a database for the provision of data for payment and the second device then being formed by a terminal. As soon as a coupling has to be brought about automatically (for example, at a fixed instant in time) via, for example, a network, the database generates the first signal intended for the terminal. In response to said first signal, the terminal generates the second signal which is intended for the database and which comprises the definition signal such as, for example, a password. The database compares said password with a password stored in the database and related to said terminal, after which, in the event of them being identical, the terminal is authenticated by the database and the provision of data to the terminal can be started by the database.
Such a system has, inter alia, the disadvantage that if a swindler copies the relevant section of the terminal to a number of private terminals, said swindler could bring about a coupling to the database via any of said private terminals at the expense of a third party.