Fuente: WIPO "rice" A method of developing fortified software using external guards, identifying information, security policies and obfuscation. External guards protect protected programs within the fortified software that they are not part of. The external guards can read and check the protected programs directly to detect tampering or can exchange information with the protected programs through arguments of call statements or bulleting boards. External guards can read instructions and check empty space of the protected program before, during or after it executes, and can check for changes in the variables of the protected program when it is not executing, to more effectively detect viruses and other malware. The identification information can be stored in lists or generated dynamically and registered between the relevant programs for identification purposes during execution.