摘要

随着Internet技术与多媒体技术的飞速发展，数字化信息可以以不同的形式在网络上方便、快捷地传输。多媒体通信逐渐成为人们之间信息交流的重要手段。多媒体信息安全技术的研究主要有两种方法：多媒体信息加密和多媒体信息隐藏技术。信息加密与信息隐藏从不同的角度保证信息的安全，如果我们将信息加密与信息隐藏有机地相结合，可进一步提高信息的安全性。

本课题的目的是实现一个安全性比较高的图像信息安全算法，图像信息的安全主要包括图像加密和图像认证，图像加密的目的是将一幅图像明文通过一定的算法使其变成不可识别的密文，以防止攻击者截获原图像信息。图像加密有多种方法，本课题采用的算法是基于DES和RSA的混合加密。虽然加密可以使原文信息不被暴露，但一旦原文被接收并被篡改，加密就显得无能为力了。此时，就需要图像认证的技术。图像认证的作用就是鉴定原图像有没有被篡改，以保护发送者的利益。为实现图像认证的目的，本课题采用报文摘要结合数字水印的方法。最后，本课题从安全性角度实现了二者的结合，使得图像信息的安全得到了进一步的提高。

关键词：信息安全；图像加密；图像认证；数字水印

Abstract

With the Internet technology and the rapid development of multimedia technology, digital information can be transfered in different forms on the web quickly and easily. Multimedia communication has gradually become an important means of information exchange between people. Multimedia Information Security Technology there are two main ways: multimedia information and multimedia information hiding encryption technology. Message encryption and information hiding information from different angles to ensure the security, if we hide the information encrypted with the organic combination of information, can further enhance information security.

The goal of this topic is realizing a high-security pictorial information security algorithm, the pictorial information security mainly includes the image encryption and the image authentication, the goal of image encryption is turning a pictorial information to be distinguished through a certain algorithm,which preventing the aggressor capture the original map.The image encryption has many kinds of methods,this topic uses the algorithm of the mix encryption which is based on on DES and the RSA. Although encryption may cause the original text information not be exposed, but once the original text is received and is tampered with, the encryption appeared helplessly. This time,needs the image authentication technology. The image authentication’s function is appraising if the original map picture has been tampered with, which is to protect the transmission’s benefit. In order to realize the image authentication goal, this topic uses the method of a telegram abstract union numeral watermark.Finally, this topic has realized the two union from the secure angle,enable the security of pictorial information obtaining further enhancement.

Keywords :Security；Image encryption；Image Authentication；Digital Watermarking

摘 要

Abstract

摘要