Abstract: A device and a method are for forming a signature for use in a transmitter unit or a receiver unit of a communication system. To speed up the formation of a signature and thus the data transfer between a computer unit (e.g., a microcontroller) and a communication controller of the transmitter unit or the receiver unit, the device is arranged as hardware and the device forms the signature for data which are to be transferred from a computer unit of the transmitter unit to a communication controller of the transmitter unit for the purpose of data transmission via a communication medium of the communication system or which are to be transferred from a communication controller of the receiver unit to a computer unit of the receiver unit for further processing.