The challenges of Content Routing in P2P networks are that:
- There is no central entity orchestrating the storage and discovery of content.
- There is no central directory to find how to reach every peer in the network.
- P2P networks present high node churn.
- Thousands of peers and millions of content!
- Content Providers (P),
- Content Consumers (C),
- Content Routers (R)
- Providers store data (D) and make it available to consumers.
- Providers and consumers find each other through routers.
- Providers create advertisements called provider records (, which include content identifiers ), and propagate them to the Routers.
- Consumers query the routers using , getting 0 or more corresponding provider records
Private Information Retrieval
Consumer queries Router while hiding the content she is after.
Leaks no info on the index
Does not scale well for Router computation and communication
Private Set Intersection
Consumer queries Router Content id
Router privately computes intersection between the queried content id and its record
Small Communication via FHE
Router may need to pre-process DB (expensive, not updatable)
Provider encrypts its data.
The search function is evaluated over encrypted data.
Consumer gets the encrypted result.
Privacy from the encryption
Not efficient in practice
Data is encrypted under Consumer’s key and delegated to the Router
Deterministic Encryption: exact match
Order-Preserving Encryption: range queries
Some existing attacks to recover data