Memory Access Authority Control via Program Counter Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In systems with security protection mechanisms, such as television cards, there is a lack of proper access authority control, allowing malicious channel operators to access confidential service data from other operators, as there is no mechanism to prevent unauthorized access.
Innovation Solution
A memory access authority control method and system that utilizes a look-up table to map program counter values to permissible access intervals in a service address space, determining whether access to confidential data is allowed based on the current program counter value, ensuring that each caller program can only access its designated data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a television card stores multiple caller programs and confidential service data from different channel operators without access authority control, then the system can support multiple channel operators and their services, but malicious channel operators can access confidential service data from other operators
Solution Approach 1:
The memory address space is segmented into command address space and service address space. The service address space is further divided into multiple non-overlapped permissible access intervals, each corresponding to a specific caller program. This segmentation isolates confidential data from different channel operators into separate address intervals, preventing unauthorized access while maintaining support for multiple operators.
Solution Approach 2:
Different address intervals in the service address space are assigned different access permissions based on the caller program's identity. Each caller program has its own designated permissible access interval with specific access rights. This local quality differentiation ensures that each program can access only its authorized data while protecting other operators' confidential information.
2Reliability
If access authority control is implemented by mapping program counter values to permissible access intervals, then data security is improved, but the device complexity increases due to the look-up table and access control mechanism
Solution Approach 1:
The permissible access intervals for each caller program are predetermined and pre-configured in the look-up table during system initialization or manufacturing. This preliminary action establishes the access authority control rules in advance, so that during runtime, the memory controller only needs to perform simple look-up operations based on the current program counter value, rather than implementing complex real-time access control logic.
Solution Approach 2:
A look-up table is introduced as an intermediary structure between the program counter and the service address space. The look-up table stores mapping relationships between program counter value intervals and permissible access intervals. This intermediary simplifies the access control mechanism by providing a direct mapping relationship, avoiding the need for complex authorization logic while ensuring data security.
Data Source
AI summary
A memory access authority control method and a memory management system utilizing the method. By partitioning and designating permissible memory access intervals to different service programs in one system, it is ensured that each service program cannot access other service programs' confidential data. Thus, the security of confidential data is guaranteed.