Abstract: With the major advancements in the field of technology and electronics, one persistent obstacle has proven to be one of the major challenges, namely : Data Security. To get connected securely and quickly through the electronic data transfer through the web, the data should be encrypted. Encryption is the process of transforming plain text into ciphered-text, which cannot be understood or altered easily by undesirable people. It can also be defined as the science that uses mathematics in data encryption and decryption operations. In this paper, we discuss several important algorithms used for the encryption and decryption of data in all fields, to make a comparative study for most important algorithms in terms of data security effectiveness, key size, complexity and time, etc. This research focused on different types of cryptography algorithms that are existing, like AES, DES, TDES, DSA, RSA, ECC, EEE and CR4…etc.