In this thesis, we present results of an experimental study in order to generate a secure cryptographic key from the user’s voice which is to be shared between two mobile devices. We identified two security threats related to this problem, discussed the challenges to design the key generation/sharing mechanism, and proposed a new protocol based on bloom filters that overcomes the two main attacks by the intruder. One is when the attacker places its device in the close vicinity of the location where the user attempts to generate/share the key in order to derive the key from eavesdropping on communication messages. The second is when the attacker visually observes the experiment being performed and it tries to replicate the same experiment to reproduce the key. We present several results that demonstrate the practicality of our proposed technique in the context of communications between smart-phone