Replay Protection Circuit with Ciphertext Addressing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic transactions involving sensitive data are susceptible to memory replay attacks, where intercepted data can be replayed to gain unauthorized access, and existing defenses require significant on-chip memory for nonce storage.
Innovation Solution
A replay protection circuit generates a Message Authentication Code (MAC) using ciphertext memory addresses, obfuscating data blocks on external memory, eliminating the need for on-chip nonce storage and enhancing security by comparing generated MACs with stored MACs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing replay attack defenses are implemented, then security against replay attacks is improved, but on-chip memory requirements increase significantly
Solution Approach 1:
The patent extracts the nonce storage function from on-chip memory and relocates it to external memory. The replay protection circuit generates nonces and stores them externally, eliminating the need for significant on-chip memory while maintaining security against replay attacks.
Solution Approach 2:
The patent introduces a replay protection circuit as an intermediary component that manages nonce generation and storage. This circuit acts as a mediator between the processor and external memory, handling the complex operations of nonce management while keeping the main system simple and memory-efficient.
2Reliability
If ciphertext memory addresses are used to obfuscate data blocks, then security is enhanced, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into the replay protection circuit: nonce generation, ciphertext address generation, MAC generation, and integrity checking. By combining these functions into a single dedicated circuit, the patent reduces overall system complexity compared to distributing these functions across multiple components.
Solution Approach 2:
The replay protection circuit is self-sufficient, generating all necessary cryptographic elements (nonces, ciphertext addresses, MACs) internally without requiring external intervention. This self-service capability simplifies the overall system architecture by eliminating the need for separate management of these cryptographic components.
Data Source
AI summary
Systems and methods for memory replay protection are disclosed. In an example, a system in the form of a device includes a processor, and a replay protection circuit coupled to the processor and including a memory interface circuit, wherein the replay protection circuit is configured to generate a message authentication code (MAC) from at least one block of data and to access the at least one of block of data via the memory interface circuit using ciphertext that is generated by the replay protection circuit in response to a plaintext memory address received from the processor.