Wireless Sensor Network (WSN) assists to communicate with limited frequency and bandwidth through the group of independent nodes. WSN has an extensive application in both industrial and commercial areas to manage peril environments incorporating nuclear power plants and wilderness areas. Cryptography is used for writing secret code and it is an ancient technique. Moreover, cryptography is required in data and telecommunications in order to communicate with unreliable medium especially in the internet. Cryptography technique is classified in several ways but for this paper, the paper will be classified on the basis of number of keys used for decryption and encryption.