A method and device for authorized data entry and securing the authenticity of such data when entering cryptographic operations in a computer requiring authorized data entry, sends a specific command to an STM module which defines a template of input data intended to be cryptographically processed. The STM module is switched over to a secure typing mode, the STM module autonomously controls the typing of required data items of the data template by recording characters typed on the connected entry device, and the recorded characters are arranged by the STM module in its internal memory in requested data structures defined by the input data template, and such created data are sent by the STM module directly to a token where the requested cryptographic operation is called, the result of which is sent to the computer by the STM module, and subsequently the STM module switches back to the transparent mode.