System for data processing, the system comprising: - a network area (NC), at least one processing area (AC) and a storage area (DC), the network area, the processing area and the storage area are physically separated from each other, - the network area and the processing area and - the processing area and the storage area are coupled to each other in each case via an internal communication network, and - an access controller (ACU) which is adapted to monitor and control access to the network area, the processing area and the storage area, and to prevent access to unencrypted data, wherein - the network area (NC) is adapted to handle a communication between the system and an external system (client) via a communication network, wherein the network area is further adapted to send and receive data in encrypted form, - the storage area (DC) is adapted to store data, and - the processing area (AC) is adapted to receive data from the storage area and/or from the network area, to process the received data and to transmit the processed data to the storage area and/or to the network area, characterized in that - the processing area (AC) exclusively has volatile storage means which lose their stored content immediately after an interruption to the power supply, - the access controller (ACU) is further adapted to monitor access to the processing area (AC) and upon a detection of an unauthorized access, to interrupt the power supply of the processing area, such that the volatile memory means of the processing area lose their stored contents. - a network area (NC), at least one processing area (AC) and a storage area (DC), the network area, the processing area and the storage area are physically separated from each other, - the network area and the processing area and - the processing area and the storage area are coupled to each other in each case via an internal communication network, and - the network area and the processing area and - the processing area and the storage area are coupled to each other in each case via an internal communication network, and - an access controller (ACU) which is adapted to monitor and control access to the network area, the processing area and the storage area, and to prevent access to unencrypted data, wherein - the network area (NC) is adapted to handle a communication between the system and an external system (client) via a communication network, wherein the network area is further adapted to send and receive data in encrypted form, - the storage area (DC) is adapted to store data, and - the processing area (AC) is adapted to receive data from the storage area and/or from the network area, to process the received data and to transmit the processed data to the storage area and/or to the network area, characterized in that - the processing area (AC) exclusively has volatile storage means which lose their stored content immediately after an interruption to the power supply, - the access controller (ACU) is further adapted to monitor access to the processing area (AC) and upon a detection of an unauthorized access, to interrupt the power supply of the processing area, such that the volatile memory means of the processing area lose their stored contents. <EOS>