Encrypted Data Table Queries Against Frequency Analysis

The patent divides the original data table into multiple sub-tables based on attribute value ranges. Each sub-table contains a subset of the original data, and queries are routed to appropriate sub-tables. This segmentation prevents attackers from performing frequency statistics attacks on the entire data set, as the attack surface is divided into smaller, less informative segments.

The patent introduces a new dimension of query processing by adding sub-table routing based on attribute value ranges. Instead of direct queries to the encrypted data table, queries are first routed to appropriate sub-tables based on the search attribute and value range. This dimensional change in query processing prevents frequency analysis attacks while maintaining query functionality.

The patent performs preliminary actions by pre-dividing the data table into sub-tables based on attribute value ranges before queries are executed. The routing logic for directing queries to appropriate sub-tables is pre-established. This preliminary organization simplifies the query processing during operation, as queries can be directly routed to the correct sub-table without complex real-time analysis.

The patent introduces an intermediary routing mechanism that sits between the query interface and the encrypted data sub-tables. This intermediary component receives queries, determines the appropriate sub-table based on attribute value ranges, and forwards queries accordingly. It also manages the generation of multiple query request groups to prevent frequency statistics attacks, thereby simplifying the overall system architecture while maintaining security.

The patent applies local quality by making the query processing time cost localized to specific operations. When exact matching is required, only one query request group is transmitted. When range queries or less precise matching is acceptable, multiple query request groups are transmitted to enhance security. This selective approach optimizes the balance between security and processing time based on the specific query requirements.

The patent implements partial action by transmitting multiple groups of query requests only when needed for security purposes, rather than always transmitting all possible query groups. The system dynamically determines the appropriate level of query request groups based on the query type and security requirements, thereby avoiding unnecessary processing time overhead while maintaining security when needed.