Abstract: An electronic data processing device, comprising an access protected memory, provided for storing secure data and a data processing member, provided for processing said secure data, said terminal comprises a tampering detection and protection circuit provided for detecting a tamper condition and for generating a tamper signal upon detection of said tamper condition, said tampering detection and protection circuit being connected to a tampering sequencer, provided for disabling said processing member upon receipt of said tampering signal, said memory comprises a security register provided for storing keys for encrypting said secure data and a memory section provided for storing keys for encrypting said secure data and a memory section provided for temporarily storing secure data processed by said data processing member, said tampering sequencer comprises an internal clock generator provided for generating, upon receipt of said tamper signal a tamper pulse and a series of clock pulses, said tampering sequencer

Abstract: A method and a device for reading out keys of a keyboard. The read-out is realised by randomly generating a scanning pattern comprising for each row and column a read-out value to be applied on the rows and columns. The scanning pattern is preferably changed after having been applied to the keys. After application of the randomly generated pattern, the verification routine is applied in order to identify the selected keys.