ABSTRACT. Nowadays large amounts of data are being transferred over different network channels that could be both public and private. Protecting information is more vital than ever. One of the main problems during transferring data is to ensure security. Nowadays the exchange of valuable information over Internet, such as bank transactions, credit card numbers and telecommunication services are already common practices. Because the world becomes more connected and communication methods are developed, the security on electronic services has become more important. In order to protect valuable data in computer and communication systems from unauthorized attack and modification different security methods must be involved. Cryptography is one such method to make sure that confidentiality, authentication, integrity, availability and identification of user data can be secured. Cryptography provides security and privacy of used data. Encryption is the process of converting normal data or plaintext to something incomprehensible or cipher-text by applying mathematical transformations or formulae. These mathematical transformations or formulae used for encryption processes are called algorithms. At the present time, cryptography plays important role to provide security communication between multiple objects. In many modern studies, researchers are trying to identify best cryptography mechanisms with their strong and weak points in terms of their performance results. To select cryptographic technique according to a particular situation is not so easy task. To solve this issue we have to understand that technique selection is totally dependent on desired quality attributes such as efficiency and security. In this paper is presented critical analyze of some cryptography algorithms DES, 3DES, AES, Blowfish and RSA is presented. According to the literature review we have analyzed the performance and efficiency of those algorithms. To make an evaluation of those systems was explained imitations of sample context. We have analyzed various encryption algorithms on the basis of different parameters and compared them to choose the best data encryption algorithm so that we can use it in our future work.