embodiments of the present invention disclose a method and system for protecting the security of encrypted software . specifically , the present invention pertains to a method of decrypting only those steps or portions of the software that are written to a processor &# 39 ; s internal instruction cache . while in storage in non - volatile memory and in ram , encrypted software remains in an encrypted state . the invention includes a decryption unit that may be located internal to the processor and performs decryption of the software as it enters the instruction cache . by use of this method , encrypted software is resistant to copying from ram in a decrypted state for subsequent reverse engineering . software that is protected by this method could be any intellectual property meant to processed by computer that is delivered to the user by internet , cable , direct satellite , packaged media , or any other means .