RPMB Storage Access With PIU Authentication Against Replay Attacks

The memory device is segmented into traditional memory blocks and a specialized replay protected memory block (RPMB). The RPMB is further divided into a data area for storing protected data and a metadata area for storing authentication information. This segmentation allows security-critical operations to be isolated in the RPMB while leaving other memory blocks unchanged, thus improving security without unnecessarily complicating the entire device architecture.

An intermediary authentication mechanism is introduced between the host and the memory controller. The memory controller acts as an intermediary that verifies authentication information (such as message authentication codes) before allowing access to the RPMB. This intermediary layer enforces security protocols without requiring the host to directly implement complex security logic, thereby improving security while managing device complexity through specialized intermediary components.

Authentication information, including message authentication codes (MAC) and metadata, is pre-stored in the metadata area of the RPMB during system initialization or data writing operations. When read operations are performed, the pre-stored authentication information is quickly verified against the retrieved data, eliminating the need for complex real-time authentication calculations. This preliminary preparation significantly reduces processing time while maintaining strong data integrity verification.

The authentication protocol uses copying of authentication information between the metadata area and temporary storage during verification. Instead of performing complex cryptographic operations during each read operation, the system copies and compares pre-computed authentication tags (MACs) with the retrieved data. This copying-based verification approach is computationally efficient and minimizes processing time while ensuring data integrity.