The rapid evolution of the embedded era has witnessed globalization for the design of SoC architectures in the semiconductor design industry. Though issues of cost and stringent marketing deadlines have been resolved in such a methodology, yet the root of hardware trust has been evicted. Malicious circuitry, a.k.a. Hardware Trojan Horse (HTH), is inserted by adversaries in the less trusted phases of design. A HTH remains dormant during testing but gets triggered at runtime to cause sudden active and passive attacks. In this work, we focus on the runtime passive threats based on the parameter delay. Nature-inspired algorithms offer an alternative to the conventional techniques for solving complex problems in the domain of computer science. However, most are optimization techniques and none is dedicated to security. We seek refuge to the crypsis behavior exhibited by geckos in nature to generate a runtime security technique for SoC architectures, which can bypass runtime passive threats of a HTH. An adaptive security intellectual property (IP) that works on the proposed security principles is designed. Embedded timing analysis is used for experimental validation. Low area and power overhead of our proposed security IP over standard benchmarks and practical crypto SoC architectures as obtained in experimental results supports its applicability for practical implementations. © 2017 ACM.