Abstract: The invention relates to a method of controlling a device able to function in a mode with code verification or in a mode without code verification to effect a transaction, the method including a step of authenticating the device, an optional step of verifying a code, and a stage of continuing the transaction, wherein the method further includes a first verification step of verifying whether the device is functioning in the mode without code verification; and if so, the stage of continuing the transaction includes a step of making the transaction secure including determining a history of preceding transactions of the device in the mode without code verification, processing the transaction securely as a function at least of the history, and updating the history. The invention relates to a device able to function in accordance with such a control method.