Encryption interface technologies are described. A processor can include a system agent, an encryption interface, and a memory controller. The system agent can communicate data with a hardware functional block. The encryption interface can be coupled between the system agent and a memory controller. The encryption interface can receive a plaintext request from the system agent, encrypt the plaintext request to obtain an encrypted request, and communicate the encrypted request to the memory controller. The memory controller can communicate the encrypted request to a main memory of the computing device.