FIELD: physics, computer engineering.
SUBSTANCE: invention relates to software protection. The apparatus comprises a program counter, memory for storing an encrypted program, wherein said encrypted program comprises a set of encrypted commands, which include an operation code, and said apparatus comprises a decryption unit and a data processing unit and has access to an initialised command key, a command key recursive update means based on the entire said command key or part thereof and a digest of at least one previous executed command.
EFFECT: improved security when analysing software.
12 cl, 3 dwg
