A processor employs a hardware encryption module in the processor's memory access path to cryptographically isolate secure information. In some embodiments, the encryption module is located at a memory controller (e.g. northbridge) of the processor, and each memory access provided to the memory controller indicates whether the access is a secure memory access, indicating the data associated with the memory access is designated for cryptographic protection, or a non-secure memory access. For secure memory accesses, the encryption module performs encryption (for write accesses) or decryption (for read accesses) of the data associated with the memory access.