5G Espresso Algorithm for Image Encryption

Cryptography techniques are critically important for secure storage of data and transmission over exposed systems, for example, the web. For high security, encryption is one of the approaches to guard the information from leakage. Providing security to Image transmitted over the network is in demand as data is vulnerable over the unprotected medium. Encryption is one of the popular approaches for providing such security [5]. In this paper generation of key sequence using Espresso algorithm is discussed and its application for encryption and decryption of gray scale images is presented. Performance of the proposed algorithm is analyzed by computing Histogram and Entropy of the original and encrypted image. Generation of binary sequence using Espresso algorithm corresponding to 256 bit key is implemented on Xilinx Spartan II: 5v1x30ff324-3 (application version) FPGA, ISE simulator using Verilog coding and results are discussed.