This paper presents analysis of network data encryption and decryption techniques used in communication systems. In network communication systems, exchange of information mostly occurs on networked computers, mobile phones and other internet based electronic gadgets. Unsecured data that travels through different networks are open to many types of attack and can be read, altered or forged by anyone who has access to that data. To prevent such an attack, data encryption and decryption technique is employed. In order to visualize the effect and evaluate the performance of the encryption and decryption of each technique used in communication systems, Visual Basic simulation program that encrypt and decrypt data were developed, written and tested. Different data block sizes were captured and plotted against total time response taken during data encryption using Microsoft Excel. The graph result shows the superiority of RSA and AES algorithms over other algorithms in terms of the processing speed and time. DES has worm holes in its security mechanism whereas Blowfish, AES, and RSA do not have any. Further analysis was made based on the graph result obtained on each data encryption techniques.