In a wireless network, when the adversary is being part of the network, they are well known about the protocol being used and other network secrets. A transceiver is enough to get the key and decrypt the message. Hence, simple cryptographic mechanism is not enough to protect the message. Moreover, jamming can be easily performed by modifying the packet header. At the message level permutation and padding are used to protect the message and at the communication level puzzle is used to hide the key. A puzzle solver module in the client system can solve the puzzle and get the key. Attacks are of various types that effect confidentiality and integrity of wireless network and in this paper we are discussing about Jamming attacks. Jamming can stop or disrupt wireless transmission. It is interference, noise or collision at the receiver end. Jamming may happen unintentionally by network load or intentionally in form of attack. No specific hardware is used for executing it, it can be easily implemented by listening to the open medium and broadcasting in the frequency band same as network. If it is executed successfully it gives significant advantages to the attacker at very low cost. That is the reason why it is effective