Efficient Content Authentication over Distributed Hash Tables

We study a new model for data authentication over peer-to-peer storage networks, where data is stored, queried and authenticated in a totally distributed fashion. The model captures the security requirements of emerging distributed computing applications. We present an efficient implementation of a distributed Merkle tree, which realizes a Merkle tree over a peer-to-peer network, thus extending a fundamental cryptographic authentication technique to a peer-topeer distributed environment. We show how our distributed Merkle tree can be used to design an efficient authenticated distributed hash table. Our scheme is built on top of a broad class of existing distributed hash table implementations, is efficient, and achieves generality by only using the basic functionality of object location. We use this scheme to implement the first distributed authenticated dictionary.