A new image stream encryption technique

Abstract

This paper introduces a self-synchronous stream cipher with a considerable key space. In the proposed technique, the parity bit plane of a public image is used to encrypt the message. Simulation results showed that the histogram of the ciphered image is uniform representing almost equivalent probability of occurrence of each intensity level. The entropy of the ciphered image is almost equal to the theoretical value of 8, indicating that the information leakage in the proposed encryption process is negligible. The correlation coefficients of the ciphered image prove that there exists almost zero correlation between its pixels. The simulation results also showed that the proposed technique is highly sensitive to the four different parts of its password. Also, the plain-text attack analysis gave NPCR and UACI values that are close to ideal. The proposed technique is computationally simpler than other image encryption techniques in the literature. Finally, a high PSMSE of 83 dB in the decoded image was achieved at a ciphered bit error rate of 10-4. Therefore, the proposed stream cipher can be efficiently used in real time multimedia and wireless applications.