This document summarizes a study that evaluates the performance of four symmetric key cryptography algorithms: DES, 3DES, Blowfish, and AES. The study considers criteria like file size, file type, encryption and decryption time, and block size. It finds that Blowfish has the best performance, encrypting and decrypting data faster than the other algorithms. AES also performs well, while 3DES has the lowest performance due to its longer key length. The document reviews related literature comparing the performance of symmetric key cryptography algorithms and techniques that combine cryptography with steganography for enhanced security.