Research & Papers

Secure two-party controller protocol stabilizes inverted pendulum on cloud

New protocol enables infinite-horizon control without decryption – tested on commercial cloud.

Deep Dive

A team of researchers (Teranishi, Suh, Tanaka) has experimentally validated a secure two-party computation protocol for running dynamic controllers over secret sharing. The protocol overcomes limitations of homomorphic encryption-based encrypted control by eliminating the need for controller-state decryption, state reset, or input re-encryption, enabling infinite-horizon operation. However, the two-party setup introduces extra online communication between computing parties, raising concerns about real-time feasibility.

To test real-world viability, the authors implemented the protocol on a commercial cloud platform and used an inverted pendulum testbed as a benchmark. Despite the added communication overhead, the controller successfully stabilized the pendulum, demonstrating the protocol's practicality for time-sensitive control tasks. The results, presented in a 6-page paper with 5 figures, suggest that secure distributed control can meet real-time constraints even with cryptographic protections.

Key Points
  • Protocol uses secret sharing instead of homomorphic encryption to avoid controller-state decryption and resets.
  • Enables infinite-horizon control, a key advantage over prior encrypted control schemes.
  • Experimental validation on a commercial cloud with an inverted pendulum shows successful stabilization despite online communication overhead.

Why It Matters

Proves secure distributed control can be real-time feasible, enabling privacy-preserving industrial automation and critical infrastructure.