Data Card Verification for Secure Cross-Account User Data Sharing

The patent introduces a data card as an intermediary object that mediates data sharing between accounts. The data card contains encrypted user data and can be selectively issued to specific accounts, enabling controlled data utilization without direct exposure of raw user data. This resolves the contradiction by allowing productivity improvement through data sharing while maintaining security through the intermediary data card mechanism.

The patent creates a copy of user data in the form of a data card that can be distributed to multiple accounts. Instead of sharing the original user data directly, the system generates data cards containing necessary information that can be safely shared. This allows multiple accounts to utilize data copies while the original user data remains protected, resolving the security-productivity contradiction.

The data card is designed as a universal object that can be used across multiple accounts and services. The same data card structure and verification mechanism work for different types of data sharing scenarios, reducing the need for separate complex systems for each account pair. This multi-functionality improves data sharing capability while controlling system complexity through standardization.

The verification processing unit automatically verifies data cards using cryptographic signatures without requiring manual intervention. The system performs self-service verification where the validity of data cards is automatically checked through digital signature validation, reducing operational complexity while enabling versatile data sharing between multiple accounts.