In nanometer technology regime, design components mandate their reuse to meet the complex design challenges and hence comprise Intellectual Property (IP). Unauthorized reuse raises major security issues. IP mark(s) is embedded into a design for establishing the veracity of a legal IP owner/buyer. However, methods for trustworthy public verification of IP marks are not secure. For field-programmable gate-array (FPGA) designs, marks become prone to tampering, and even being overridden by an attacker's signature after public verification. In order to ensure trustworthy yet leakage-proof public verification based on the marks hidden in a FPGA design, we propose a zero-knowledge protocol Verify-ZKP. It is an interactive two-person game between the prover and the verifier. This protocol is fast, incurs no additional design overhead, and needs no centralized signature database. We establish that Verify-ZKP satisfies zero-knowledge property, and introduce statistical metrics to measure its robustness. We have simulated our protocol for IWLS'05 FPGA benchmarks. Experimental results on robustness and overhead are very encouraging. © 2012 IEEE.