TigroEXH

Benchmark harness for the encrypted multi-map behind TIGRO (PETS 2026). C++ client, proxy and Path ORAM server, with the latency and queue-size experiments.

TigroEXH is the experiment harness for the encrypted multi-map (EMM) behind TIGRO, our PETS 2026 paper on trust infrastructure for grassroots organizers. It measures what the EMM’s queue-based query processing (the EXH mode) costs in latency and queue size under Poisson query arrivals, with a Path ORAM storage server as the back end.

Two clients issue keyword queries over an inverted index of N keyword/document pairs with exponentially distributed inter-arrival times of rate λ. A proxy turns each query into a stream of fixed-size sub-tokens, real ones padded with dummies, that is served from a queue, and a storage server answers the resulting Path ORAM accesses over TCP. The harness records per-client latency and the number of sub-tokens waiting in the queue, for N ∈ {2¹⁰, 2¹², 2¹⁴} and λ ∈ {2, 4}, plus an asymmetric case with λ₁ = 4 and λ₂ = 2.

Mean query latency per client for the asymmetric arrival rates, as database size grows.

The repository holds the C++ benchmark driver, the Asio storage server, a gRPC prototype of the leaf/path exchange, the raw measurements and the plotting script. The EMM core (the LAT client/proxy class and the Path ORAM implementation) lives in a separate module and is not published, so the repository documents the experimental setup rather than a build-ready system.

Code and measurements: github.com/Bahi7/TigroEXH.