Anonymous Identifier Routing for Stateless CCN

The patent segments the traditional monolithic FIB into a hierarchical structure with a global FIB at core routers and local FIBs at edge routers. The global FIB stores only aggregate routing information for content prefixes, while local FIBs store mappings for locally cached content. This segmentation reduces the size of FIBs at individual nodes and distributes the lookup burden across multiple levels, thereby improving lookup time while managing FIB size.

The patent introduces a new dimensional approach by adding a hierarchical level to the traditional flat FIB structure. Instead of a single-level mapping from content prefix to neighbor, the system creates a two-dimensional hierarchy: global FIB (content prefix to anchor router) and local FIB (content prefix to local neighbor). This dimensional change allows the system to manage large routing tables more efficiently and perform lookups faster by checking local FIB first before querying global FIB.

The patent extracts the per-Interest forwarding state from the traditional PIT and replaces it with a new Interest-waiting table (IWT) that stores only aggregate information about pending Interests grouped by content prefix. Instead of maintaining individual entries for each pending Interest in the PIT, the system extracts the essential forwarding information and stores it in a compact IWT structure, significantly reducing the state storage requirements and making the system more resistant to Interest-flooding attacks.

The patent applies local quality by making the IWT size dependent on the number of distinct content prefixes rather than the number of pending Interests. This means that even if there are many pending Interests for the same content prefix, the IWT stores only one aggregate entry per prefix. This local optimization at the prefix level reduces the overall table size and improves security against flooding attacks while maintaining the necessary forwarding functionality.