Two-Tier Hash for DoS Mitigation in Distributed Networks

The patent divides the traditional single hash table into a two-level hierarchical structure: a first-level hash table with fewer buckets that provides coarse-grained distribution, and second-level hash tables with more buckets that provide fine-grained distribution. This segmentation resolves the contradiction by maintaining simple implementation at the first level while achieving balanced distribution and good performance at the second level.

The patent transitions from a one-dimensional hash table structure to a two-dimensional hierarchical structure. The first level provides coarse distribution with fewer buckets, and the second level provides fine distribution with more buckets. This dimensional change allows achieving uniform entry distribution without proportionally increasing overall structure complexity, as the first level acts as a simplifying intermediary.

The patent segments the buckets into two hierarchical levels: a first level with a smaller number of buckets that reduces memory overhead and provides coarse distribution, and a second level with more buckets that achieves fine-grained distribution and good insertion performance. This segmentation resolves the contradiction by distributing the bucket burden across two levels rather than concentrating all buckets in a single level.

The patent incorporates a feedback mechanism where the system monitors hash table performance and detects potential DoS attacks or uneven load conditions. When anomalies are detected, the system dynamically adjusts the distribution strategy or triggers rebalancing operations. This feedback loop maintains implementation simplicity while significantly improving reliability under attack conditions.