Arrangement for increasing secure manipulation of critical data, particularly data registered in franking machine

摘要

The control unit (6) has a microprocessor or an OTP (one-time programmable) processor that has, in addition to CPU (6a), other units in common housing, forming the OTP ROM (6b), and OTP ROM (6c) and acting as a security unit against unauthorised manipulation. The first non-volatile memory (NVM 20) is an EEPROM, serving as a second line of defence against manipulation. There is also an external non-volatile memory (NUM 25) acting in the same way connected to the processor (6) through an input/output control module (4), particularly against taking information out.