Smartcard Dual Microprocessor Command Routing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid smartcards with independent microprocessors for different applications face challenges in data exchange security, cost, and compatibility with existing smartcard readers due to dedicated communication interfaces and limited contact points, making it difficult to add new functions without modifying the reader's electronics and exposing data to security risks.
Innovation Solution
A smartcard design with two interconnected microprocessors, where one microprocessor determines and directs commands received over different communication channels, allowing for efficient data exchange and security enhancement without additional contacts, using standard microchips and maintaining compatibility with existing readers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If independent microprocessors are used for different applications, then application security and independence are improved, but data exchange security deteriorates and device complexity increases
Solution Approach 1:
A bus interface unit is introduced as an intermediary component between the first microprocessor (handling high-security applications) and the second microprocessor (handling low-security applications). This mediator controls and monitors all data exchanges between the two processors, ensuring that sensitive data from the high-security application is protected during transmission to the low-security application, thus resolving the security risk while maintaining application independence
2Reliability
If dedicated communication interfaces are provided for each microprocessor, then application independence is improved, but device complexity and fabrication cost increase
Solution Approach 1:
The bus interface unit serves multiple functions: it acts as a communication interface for the first microprocessor, another communication interface for the second microprocessor, and a security mediator between them. By making this single component multi-functional, the patent eliminates the need for separate dedicated communication interfaces for each microprocessor, thereby reducing device complexity and fabrication cost while maintaining application independence
3Ease of manufacture
If conventional smartcard contacts are reused for new functions, then ease of manufacture and compatibility are improved, but the number of available contacts for additional processors is limited
Solution Approach 1:
The patent combines multiple communication functions into a single contact interface. The first communication interface and second communication interface both utilize the same physical contact on the smartcard, allowing multiple processors to share the limited contact resources. This merging approach enables the inclusion of additional processors while maintaining compatibility with conventional smartcard readers that have a fixed number of contacts
Data Source
AI summary
A smartcard (1) includes:a first and a second microprocessor (110, 210),elements for receiving (14) commands each coming from a first or a second communications channel external to the card (1) and for transmitting the received commands to the first microprocessor, characterized in that the first microprocessor includes elements for determining (706) whether a received command has been received on the second communications channel so as to transmit (708) the received command to the second microprocessor (210) in the case of a positive determination. Notably, the determination can be carried out by detecting an electrical contact of the communications interface of the card, over which the command is received. Application of the invention to a card having a second microprocessor for executing a highly securitized application, of the banking transaction type, and a first less securitized application, of the mobile telephony application type.