Open networks enable data communication between different types of mobile devices that showcase the need to enforce elevated security measures. Securing sensitive or confidential data in mobile phones is accomplished by implementing a diverse range of cryptographic techniques. While encryption algorithms, such as Rivest–Shamir–Adleman (RSA) may offer secure solutions that are often difficult to compromise, these in turn prerequisite high speed computational resources for effective operation. Elliptical curve cryptography (ECC) is well thought-out standard that offers a workable and feasible methods of encryption/decryption, whilst being applicable to resource constraint devices. This paper implements a novel key exchange mechanism that helps to secure exchange of data between the communicating mobile devices. The study aims to address the limitation of Elliptic Curve Deffie Hellman, which is susceptible to Man-in-the-Middle attack and proposes an enhanced Elliptic Curve Deffie Hellman (ECDH) technique for secure data communication in open networks. The study results reveal, how the implementation of ECDH allows exchange of keys between the two communicating devices with limited resources.