A method and a display preparation unit are proposed for the execution of a transaction during which transaction data are processed which have to be confirmed by a user. The display preparation unit (20) has a converter unit (29) which converts transaction data to be interpreted into pixel values and displays them on a monitor (6), an interface of its own for directly attaching an input unit (7) via which a user confirms displayed transaction data, as well as a crypto unit (31) for generating a signature for a record of confirmed transaction data. In a variant the confirmation can be effected by the crypto unit (31) generating and displaying a random number which has to be inputted by the user via a conventionally attached input unit (14).