The concept of cryptography techniques are discussed, which involve comparative analysis of three algorithms (AES, RSA and ECC) used for encryption. As security issue has become an important issue in data communication. Encryption has come up as a solution, and plays an important role in information security. The security mechanism uses some algorithms to scramble data into unreadable text which can be only being decoded or decrypted by the party that possesses the associated key. These algorithms consume a significant amount of time and have a significant value of complexity .The comparison is performed based upon the experiments performed using NS2 simulator by taking two different parameters i.e. (i) computation time ii) complexity. Encryption algorithms are categorized into Symmetric key (private) and Asymmetric (public) key.RSA is a commonly adopted public key cryptography algorithm. This book covers comparative analysis of these algorithms and brings us on conclusion as to which algorithm is more efficient and why?