The Application Research Of Visual Cryptography In Dedicated Computer System

Secret sharing is a cryptography technique that can prevent the secret information being highly centralized and guarantee the security and complete recovery of the secret information. As a brand new kind of secret sharing scheme, visual cryptography can conduct secret sharing for the image information safely and effectively. Because the visual cryptography has the advantages of simple decryption process which can recover the secret images by human visual system directly without any knowledge of cryptography and complex calculations, as well as higher security, visual cryptography has been widely used in digital watermarking and biometric identification.In the key areas of the military and government agencies, in order to protect the safety storage and the use of sensitive data in the computer, the concept of dedicated computer was born. Dedicated computer refers to the computers who have installed the dedicated computer management system and whose internal network was physically isolated. In order to ensure the confidentiality, integrity and availability of the internal data in dedicated computer, this paper will research the issue of the secure storage of the sensitive image information in dedicated computer. According to the sensitive information encryption scheme and authentication in dedicated computer system, work will be carried out in the following three parts:(1) Focusing on the cheating problem in the process of secret sharing, this paper has proposed an anti-cheating visual cryptography scheme based on chaotic encryption technology, by which the sharing images was encrypted by a trusted third party,and the processed image is stored in a dedicated computer terminals to conduct the recovery of the secret. Simulation results and analysis show that this scheme can effectively prevent cheating in participants and the contrast of the recovery image is acceptable.(2) Traditional visual cryptography can only share one image. Large number of share images will cause additional storage space and increase the difficulty of the share images management. This paper presents a multi-secret visual cryptography scheme based on random grid, which can recovery multiple secret images by less sharing images. Simulation results and analysis show that this scheme can meet the security requirements,and effectively enhance the contrast of the recovery image.(3) In order to achieve secure user authentication in dedicated computer system. In this chapter, we have proposed a multi-factor two-way authentication protocol based on visual cryptography scheme and biometrics identification technology. After the user makes a request to access a dedicated computer, a dedicated computer will authenticate the user’s biological information with UKEY’s computing and data storage capacity as well as biometric key-binding technology, then executes bidirectional authentication by means of a visual cryptography scheme between the user and a special purpose computer to further ensure the reliability of certification. Security analysis shows that the multiple authentication methods in this protocol ensure the safety and reliability of the authentication result during the certification process, resist multiple attacks, meet the security requirements of authentication.