Multimedia encryption with different security levels using recursive sequences

Multimedia services and digital communication technologies provide many different opportunities and approaches for people all over the world to share, transmit and access the images, videos and multimedia data with private or business information. As a result, providing security for images, videos and multimedia data becomes an important and urgent issue not only for individuals and companies but also for governments. Security and protection of multimedia information data are important in many areas such as privacy and copyright protection, video-on-demand, confidential remote video conferencing, security communication, and also in military applications. Multimedia encryption technologies are very useful tools to ensure multimedia data only available for authorized users by transferring the multimedia into an unintelligible format.; In this thesis, we introduce a general multimedia encryption system which is simple to implement since it has minimal hardware requirements. The presented encryption system can encrypt all different types of multimedia data, for example, videos, images, fingerprints, and electronic signatures, by using different key-dependant recursive sequences. The sequence generator allows users choose many different sequences using many different keys and parameters. This makes the encrypted multimedia data extremely difficult for unauthorized users to decode, therefore, the multimedia data is protected with higher levels of security.; Based on this general encryption system, we also introduce four new recursive sequences including the P-Lucas sequence, Generalized P-Gray Code, P-recursive and the parameter based M-sequence. Their corresponding transforms are also introduced in order to utilize these recursive sequences to encrypt multimedia data. These will increase the choices of encryption methods making unauthorized decoding harder to decipher.; To efficiently encrypt 2D and 3D multimedia data, we introduce a new general 2-D recursive sequence transform and a new general 3-D recursive sequence transform. These universal 2-D and 3-D transforms are applicable for all recursive sequences. The corresponding 2-D and 3-D multimedia encryption algorithms are also introduced such that the encryption/decryption of 2-D/3-D multimedia data is a simple one-step process. In addition, we also introduce a 3-D multimedia encryption algorithm based on the 2-D recursive sequence transform.; Experimental results show that the presented algorithms are lossless encryption approaches since the original multimedia data can be completely reconstructed by using correct security key(s). The presented encryption algorithms can partially or fully encrypt the multimedia data to meet the different security requirements.; The presented multimedia encryption algorithms are compared with other recursive sequences such as the Fibonacci number, Generalized Fibonacci number and the Gray Code. The encryption algorithms based on P-Fibonacci sequence and P-Lucas sequence show better performance in the security analysis and execution time analysis.