FrodoPIR: Simple, Scalable, Single-Server Private Information Retrieval

We design FrodoPIR — a highly configurable, stateful, single-server Private Information Retrieval (PIR) scheme that involves an offline phase that is completely client-independent. Coupled with small online overheads, it leads to much smaller amortized financial costs on the server-side than previous approaches. In terms of performance for a database of 1 million 1KB elements, FrodoPIR requires < 1 second for responding to a client query, has a server response size blow-up factor of < 3.6×, and financial costs are ∼ $1 for answering 100, 000 client queries. Our experimental analysis is built upon a simple, non-optimized Rust implementation, illustrating that FrodoPIR is eminently suitable for large practical deployments.