Security module for controlling and monitoring data traffic of a personal computer, comprising a plurality of functional components each implemented by means of hardware and software, the plurality of functional components comprising: - a programmable logic component in which a processing and control device for processing electronic data exchanged between components of the personal computer is implemented by means of programming; - a processor connection connected to the programmable logic module for exchanging electronic data with the central processor of the personal computer; - peripheral device connections connected to the programmable logic component for exchanging electronic data with peripheral devices coupled to the personal computer for data input and/or data output; and - a memory module connected to the programmable logic component, which comprises initialisation data for the logic component and control data, wherein the programmable logic component is designed to be self-initialising, wherein in the programmable logic component, by means of programming, a comparison means comprised by the processing and control means for comparing electronic data exchanged between the plurality of components of the personal computer with stored control data is implemented, wherein the programmable logic component is designed in such a way that it can detect an unauthorised exchange of data by means of the comparison means on the basis of the control data stored in the memory module and, if necessary, take corrective action, wherein, when a key is pressed on a keyboard, a signal is transmitted via this to one of the peripheral device connections and wherein the signal is decoded in the security module and wherein, if the comparison device determines on the basis of the control data stored in the memory module that a command to the processing and control device is associated with the keystroke, the command is used exclusively within the processing and control device to start a software routine, but the keystroke is not forwarded to the microprocessor. - a programmable logic component in which a processing and control device for processing electronic data exchanged between components of the personal computer is implemented by means of programming; - a processor connection connected to the programmable logic module for exchanging electronic data with the central processor of the personal computer; - peripheral device connections connected to the programmable logic component for exchanging electronic data with peripheral devices coupled to the personal computer for data input and/or data output; and - a memory module connected to the programmable logic component, which comprises initialisation data for the logic component and control data, wherein the programmable logic component is designed to be self-initialising, wherein in the programmable logic component, by means of programming, a comparison means comprised by the processing and control means for comparing electronic data exchanged between the plurality of components of the personal computer with stored control data is implemented, wherein the programmable logic component is designed in such a way that it can detect an unauthorised exchange of data by means of the comparison means on the basis of the control data stored in the memory module and, if necessary, take corrective action, wherein, when a key is pressed on a keyboard, a signal is transmitted via this to one of the peripheral device connections and wherein the signal is decoded in the security module and wherein, if the comparison device determines on the basis of the control data stored in the memory module that a command to the processing and control device is associated with the keystroke, the command is used exclusively within the processing and control device to start a software routine, but the keystroke is not forwarded to the microprocessor.