The rapid evolution of mobile devices and mobile ad hoc networks (MANET) requires the protecting data while transmitting in the network. To implement hard-cryptographic algorithm is challenging prospect in MANET. Biometric characteristic such as face, fingerprint, voice, iris, and retina can be potential alternative to generate a cryptographic key over a conventional cryptography and enhance the security. In this paper non-invertible key generation using cancelable fingerprint to provide security, authentication code and computation requirement is discussed. This proposed method has three advantages over previous system. First, authentication code is generated to provide authentication and integrity. Second, to provide security data is encrypted using non-invertible key generated from the fingerprint biometric of the receiver. Third, randomization is provided using genetic operator to protect against various attacks. The proposed model is analyzed against security attributes authentication, confidentiality, integrity. It is found that it withstands against cryptanalytic and brute force attack. We also tested computational cost of encryption time and decryption time required using generated key of different message size using Java standard edition and iPhone simulator. It is found that mobile devices take pretty less time so it suits the current mobile environments.