Kombinasi RSA-CRT dengan Random LSB untuk Keamanan Data di Kanwil Kementerian Agama Prov. Sumatera Utara

Abstract

<p><em>In this study the authors use Cryptographic Algorithms</em><em> </em><em>Rivest</em><em> </em><em>Shamir</em><em> </em><em>Adleman</em><em> </em><em>Chinese Remainder Theorem (RSA-CRT) and steganography</em><em> </em><em>technique Random Least Significant Bits (</em><em>LSB</em><em>). RSA-CRT is basically the same as usual, but utilizing RSA CRT theorem to shorten the bit size decryption exponent d by hiding d on congruent systems that accelerate time decryption, the difference in the key generation process and the decryption process. Cryptographic algorithm RSA-CRT produce ciphertext stored into a picture (image) using Steganography technique Random Least Significant Bits (</em><em>LSB</em><em>). The workings of Random</em><em> </em><em>LSB</em><em> </em><em>is storing the message (ciphertext) in the first bit or the second bit random key for use random number generator Pseudo Random Number Generator (</em><em>PRNG</em><em>) with Linear</em><em> </em><em>Congruential</em><em> </em><em>Generator (</em><em>LCG</em><em>)</em><em> </em><em>method</em><em>. Ciphertext stored in </em><em>a picture </em><em> (image) has extracted key re-use random number generator at the time of inserting the message. Then the ciphertext is decrypted back by the algorithm RSA-CRT to produce the original text (plaintext). Merging Cryptographic Algorithm RSA-CRT with Steganography Technique Simple </em><em> </em><em>LSB</em><em> </em><em>than with Random</em><em> </em><em>LSB</em><em> </em><em>generate</em><em> </em><em>higher</em><em> </em><em>PSNR</em><em> </em><em>and</em><em> </em><em>MSE</em><em> </em><em>is lower, which means better level of data security and more resistant to attack. H</em><em>as more difficult to find a secret message by cryptanalysis </em><em>and s</em><em>teganal</em><em>y</em><em>s</em><em>t.</em></p>