Steganography of Least Significant Bit Algorithm and Combination of Cryptography Vigenere Cipher with Rivest Code 4 for Email Message Security

The combination technique of cryptographic and steganographic algorithms is carried out to strengthen protection in securing data which is currently rife with hacking. The combination of the Vigenere Cipher with various algorithms is quite calculated. This study aims to determine the process of implementing the Least Significant Bit and the Vigenere Cipher combination with Rivest Code 4 in securing data messages and their performance. The research method will use the Least Significant Bit algorithm, Vigenere Cipher, and Rivest Code 4 with the waterfall development method. The Base64 algorithm will be used to convert files into text form. The results of the research will be in the form of an image steganographic cover sent via email. The results reveal that the implementation of the Least Significant Bit and the Vigenere Cipher Combination with Rivest Code 4 in securing text email messages was 100% successful after testing 20 random samples with the combination sequence starting with the Vigenere Cipher algorithm sequence then going to Rivest Code 4 then hidden with the Least Significant Bit in the encryption process while the decryption process is done in reverse order. Meanwhile, email messages in the form of files need to be converted first with the Base 64 technique to get a byte array of text so that they can be implemented in applications. Differences in the type and size of the image, the number of characters in the message content, and the number of characters in the key affect the duration of the encryption and decryption process but do not affect the pixel dimensions of the image. Meanwhile, the number of characters in the contents of the message will affect the size of the image data so that the more characters in the contents, the larger the size of the image.