Digital text and digital image encryption and steganography method based on SIYu map and least significant bit

This paper focus on keeping data and information confidentiality on digital image based on chaotic system. In this paper, we use the unmodified SIYu map for the encryption and embedding process and use 3-3-2 LSB insertion method to embed data to cover image. This paper will show how is the result of encryption process and embedding process using SIYu map. Furthermore, we will show our algorithm performance based on randomness of sequence generated by SIYu map with NIST test and entropy test, histogram analysis, goodness of fit test, quality of the stego image, quality of decrypted data, initial value sensitivity, and key space. The results show encrypted data is uniformly distributed; sequence generated by SIYu map passes all NIST test and entropy test, which means the generated sequence is random; stego image have a good quality, it can be seen from the correlation coefficient and PSNR value more than 40 dB; decrypted data has the same quality as the original data; initial value sensitivity reaches 10-16; key space reaches 2.56 × 1094; and add noises can be optional to increase data confidentiality. For the conclusion, our algorithm can be used to keeping data and information confidentiality on digital image.