Enterprises are adopting blockchain technology to build a server-less and trust-less system by assuring immutability and are contributing to blockchain research, innovation, and implementation. This led to the genesis of various decentralized blockchain platforms and applications that are unconnected with each other. Interoperability between these siloed blockchains is a must to reach its full potential. To facilitate mass adoption, technology should have the ability to transact between various decentralized applications (dapps) on the same chain, integrate with existing systems, and initiate transactions on other networks. In our research, we propose a secured authentication mechanism that enables various decentralized applications on the same chain to interact with each other using a global dapp authentication registry (GDAR). We carried out an in-depth performance evaluation and conclude that our proposed mechanism is an operative authentication solution for dapp interoperability.