Delegated Private Set Intersection via Key Segmentation

The patent segments the cryptographic key into multiple shares distributed across different delegate modules. Each module holds only a portion of the key, making it impossible for any single module or external attacker to perform brute force attacks on the complete key. This segmentation resolves the contradiction by maintaining confidentiality while eliminating the brute force vulnerability.

The patent introduces delegate modules as intermediaries between the participants and the hash calculation process. These modules apply the segmented key shares to transform the input data, creating an additional layer of security that prevents direct brute force attacks on the original data or complete key. The intermediaries protect against harmful factors while maintaining the confidentiality function.

The patent performs preliminary actions by pre-distributing key shares to delegate modules before the actual private set intersection computation. This preparation allows the main computation to proceed with fewer interactions, as the security infrastructure is already in place. The preliminary key distribution enables efficient computation while maintaining security guarantees.

The delegate modules autonomously apply their key shares to transform data without requiring continuous interaction between participants. Each module independently performs its cryptographic function, reducing the need for multiple back-and-forth interactions. This self-service approach maintains security while significantly improving computational efficiency and reducing costs.

The patent divides the single key into multiple key shares distributed across different delegate modules. This segmentation maintains relative simplicity in key management (each module manages only its share) while dramatically reducing key theft risk, as an attacker would need to compromise multiple independent modules to obtain the complete key.

The patent applies different key shares to different delegate modules, giving each module a unique local quality (its specific key share). This allows the system to maintain simple key management at the global level while creating localized security zones where each module's compromised state does not expose the entire key. The local quality differentiation reduces overall risk while preserving management simplicity.