Processing System with a Secure Set of Executable Instructions and/or Addressing Scheme

A method for securing a smartcard, the method comprising:

• generating a first set of N1 instructions of m1 bits, wherein
• m1 is a positive integer number,
• N1 is a positive integer number,
• 2m1 is greater than N1, and
• each instruction of the first set differ from all other instructions of the first set by a number of bits greater than or equal to pi, pi being a positive integer number greater than or equal to 2;
• and
• configuring a controller to make it capable of executing each instruction of the first set.

A method comprising:

• selecting a first set of N1 codes from a first group of 2m1 codes, wherein
• m1 is a positive integer number,
• N1 is a positive integer number,
• 2m1 is greater than N1, and
• each code of the first set differ from all other codes of the first set by a number of bits greater than or equal to p, p being a positive integer number greater than or equal to 2;
• selecting a second set of N2 codes from the first group, wherein the first set and the second set are non-overlapping;
• and
• storing codes of the first set into a storage device.

A method of operating a smartcard, the method comprising:

• retrieving a first instruction from a storage device, wherein
• the first instruction is an instruction from a set of secured instruction,
• the set of secured instructions comprising a first set of N1 instructions of m1 bits,
• m1 is a positive integer number,
• N1 is a positive integer number,
• 2m1 is greater than N1, and
• each instruction of the first set differ from all other instructions of the first set by a number of bits greater than or equal to p1, p1 being a positive integer number greater than or equal to 2;
• and
• executing the secured instruction.