System And Method For Generating A Signature

System for generating a signature for a data file to be sent to a recipient by a sender, comprising:

• a first device, comprising:
• a first memory;
• time-determining means for determining a first point in time and a first time interval within which the first point in time falls;
• and
• a processing unit coupled to the first memory and to the time-determining means;
• a first formula stored in the first memory;
• and
• a number of digitized biometric features stored in the first memory;
• wherein the first device is adapted to provide the data file to be sent with a first signature which is generated by the first formula on the basis of the first time interval, and
• wherein the signature comprises a number of positions, wherein each position is filled with one of the digitized biometric features in accordance with a selection differing per time interval from the number of digitized biometric features.