Key Identifier Prefix for Multi-Key Data Encryption

The patent divides the encryption process into two distinct stages: a one-time bulk encryption stage that encrypts large amounts of data using multiple encryption keys, and a fast decryption stage that uses pre-stored key identifiers to quickly retrieve the appropriate key. This segmentation allows the system to handle both large-scale encryption securely and real-time decryption efficiently, resolving the contradiction between security and speed.

The patent introduces key identifiers as an intermediary element that mediates between the multiple encryption keys and the decryption process. Each encrypted data block is associated with a key identifier that points to the specific encryption key used. This intermediary simplifies key management by eliminating the need for complex key tracking systems, as the key identifier directly links encrypted data to its corresponding key without requiring additional management overhead.

The patent performs preliminary action by pre-computing and storing key identifiers alongside encrypted data blocks during the initial bulk encryption process. This preparation work is done once when data is loaded, so that during real-time operations such as live search, the system only needs to retrieve and use the pre-stored key identifiers rather than performing complex key management or re-encryption operations. This eliminates the need for repeated heavy computational work during real-time access, maintaining both speed and resource efficiency.