Combination of columnar transposition cipher caesar cipher and lempel ziv welch algorithm in image security and compression

Abstract Exchange of information through the medium of the internet allows information can be accessed by unauthorized parties. Techniques for securing information that is commonly used is Cryptography. This research will use a combination of two classic algorithms which are Columnar Transposition Cipher and a Caesar Cipher with a Linear Congruential Generator modification. Information in the form of images often has some of the same pixel value components. For saving the memory then the writers use the technique of compression with Lempel Ziv Welch algorithm, which is a dictionary-based compression algorithm. Stages of the process used in this study are that the pictures will be encrypted using the algorithm of Columnar Transposition Cipher, next step the file that has been encrypted will be encrypted with the Caesar Cipher algorithm using a combination of and Linear Congruential generators are modified. Then the image file that has been encrypted will be compressed using the second algorithm Lempel Ziv Welch. For the implementation of programming language C # systems used. The results of this study showed that the combination of Columnar Transposition Cipher and a Caesar Cipher with a Linear Congruential Generators could keep the confidentiality, integrity, and security of data. Lempel Ziv Welch algorithm produces the value of the average compression ratio (RC) 67.05%, in Compression Ratio (CR) aspect the value is 1.49, and in Space Saving (SS) parameter, the percentage is 32.93%.