Scavenging for Anonymity with BlogDrop

Anonymous communication schemes that provide strong traffic analysis resistance (e.g., DCnets and Mix-nets) are too slow for large-scale interactive use. Low-latency systems (e.g., Tor) provide users with alarmingly small anonymity set sizes, especially in heavily monitored networks. We present preliminary work on a new anonymity protocol that makes this anonymity/latency trade-off an explicit and user-adjustable parameter. We call our technique anonymity scavenging: the longer a user is willing to wait for a message to leave the system, the more anonymity that user will be able to scavenge from other users. Our protocol builds upon previous provable schemes, and we expect formal proofs of security to be a large component of future work.