Wireless networks are capable solutions for many industrial and commercial applications. However, a wireless node endures with lots of constraints such as low computation ability, little memory, partial energy resources and so on. In secure communication, different numbers of end devices are used to share the information between wireless devices and also are protected with the help of crypto algorithm and secret keys. The secret keys play a very important role than the algorithm, to ensure the security of the information between different numbers of users. When members of a group need to accept the similar information security and are permitted to dynamically join or leave the group, security entails not only sharing of a secret among lots of users but also be worried with security services like confidentiality, integrity of information as the connection changes. Whenever the system changes, the system manager is responsible to change the secret and supporting keys and to send back the updated keys to the group members. These different numbers of secret keys used in the end devices are generated using software and hardware techniques. In this study the different numbers of secret keys are generated using hardware. LPC 2148 are used to generate the random secret session key with real time parameters, event driven circuits and temperature measurement unit. In all the scenarios, the randomness, issues in hardware are analyzed and discussed.