A security module for controlling and monitoring data traffic in a computer system including a central processor (personal computer) that has a plurality of functional components each implemented by hardware and software, said functional components comprising: - a programmable logic component which controls and monitors data traffic in the personal computer and in which, by means of programming, a process and control device for processing electronic data exchanged between the components of the personal computer is implemented; wherein the process and control unit is operable to control all the functional components of the security module independently of the microprocessor, wherein the programmable logic component is designed to auto-initialise itself when the operating voltage is switched on, wherein the programmable logic component is designed to detect unauthorised data exchange and, if necessary, take corrective actions; - a processor connection connected to the programmable logic component for exchanging electronic data with a central processor of the personal computer; - peripheral device connections connected to the programmable logic component for exchanging electronic data with peripheral devices for data input and/or data output connected to the personal computer; and - a memory module which is connected to the programmable logic component and comprises initialisation data for the logic component, wherein a comparing means comprised by the process and control unit is implemented in the programmable logic component by means of said programming and serves for comparing electronic data exchanged between components of the personal computer with predefined stored monitoring data; and wherein the stored monitoring data can be adjusted depending on incoming electronic data, wherein a received data sequence is recognised by the comparing means which then triggers a predefined control function that, as a result, causes the monitoring data to be adjusted, said data sequence being received via the keyboard or via the network connection of the personal computer. - a programmable logic component which controls and monitors data traffic in the personal computer and in which, by means of programming, a process and control device for processing electronic data exchanged between the components of the personal computer is implemented; wherein the process and control unit is operable to control all the functional components of the security module independently of the microprocessor, wherein the programmable logic component is designed to auto-initialise itself when the operating voltage is switched on, wherein the programmable logic component is designed to detect unauthorised data exchange and, if necessary, take corrective actions; - a processor connection connected to the programmable logic component for exchanging electronic data with a central processor of the personal computer; - peripheral device connections connected to the programmable logic component for exchanging electronic data with peripheral devices for data input and/or data output connected to the personal computer; and - a memory module which is connected to the programmable logic component and comprises initialisation data for the logic component,