Computer systems such as smart cards having memory architectures that can protect security information, and methods of using same

摘要

A computer system includes first, second and third memory areas. The first memory area stores therein at least one general application program including at least one subroutine call to the second memory area. The second memory area only stores therein at least one subroutine call to the third memory area. The third memory area stores therein at least one security application program that is only callable by a subroutine call from the second memory area. A processing system is configured to execute a general application program in the first memory area, including a subroutine call to the second memory area, and to unlock the third memory area only upon executing a subroutine call from the first memory area to the second memory area. The processing system may be further configured to prevent unlocking the third memory area while executing a general application program in the first memory area.