Digital information encrypted in an image using binary encoding

This paper proposes a new type of encoding methods to encrypt hidden (covert) information in host images. The encrypted information can be plot, fax, word, or network data, and it must be encoded with binary codes. All the pixels in an encoded (overt) image modulated from a host image are classified into three groups. The first group of pixels is called identification codes, used to judge whether the overt image is encoded by a method proposed in this paper or not. The second group of pixels is called type codes, used to judge the encoding type. The third group of pixels is called information codes, used to decode the encoded information. Applying the proposed encoding methods is quite convenient, and host images are not needed for decoding. Decoding covert information from overt images is rather difficult for un-authorized persons, whereas it is very easy for designers or authorized persons. Therefore, the proposed methods are very useful.     

分析半导体工艺设备中可编程逻辑器件

本文介绍在半导体工艺设备中常见的可编程逻辑器件，以及分析电器板中的可编程逻辑器件，写出已加密GAL器件的逻辑功能。     

VHDL语言在描述DES加密机中的应用

文章提出了以VHDL语言为手段，介绍了在描述DES加密机的应用，并在Active-HDL模拟验证描述的正确性。     

一种双方不可否认的小公钥RSA加密协议

文章首先改进了一个小公钥的RSA加密方案。然后，基于RSA签名算法，设计了一个双方不可否认的小公钥RSA加密协议。在这个协议中，发送方只需对发送消息进行一次密文签发。通过服务器。掇文可安全地发送给任意有限个接收者。该协议具有发送和接收双方都不能抵赖的性质。最后，探讨了该协议的实际应用。     

基于HMAC的加密狗设计

软件的盗版问题对软件公司而言是一个需要重点面对的问题,因为一个随意的盗版行为将会给软件公司带来严重的后果。很多＂盗版者＂只是些随意复制者,他们虽然只购买了一份授权,但认为将软件复制到多台机器是可以接受的做法。为了防止软件盗版,一个比较好的办法就是使用软件加密狗,只有在计算机上插有合法的加密狗,软件才能正常使用。通过这种做法可以避免软件被任意复制,从而保证软件厂商的合法利益。文中把加密狗与密码学相结合,使用密码学中的HMAC技术来保证软件的安全性。     

Binary encoding method to encrypt Fourier-transformed information of digital images

An encoding method is used to encrypt the Fourier-transformed information of a hidden (covert) digital image in an overt image, while the Fourier-transformed information must be encoded with binary codes. All of the pixels in an overt image are classified into five groups that are called identification, type, tracing, dimension, and information codes. Identification codes are used to judge if the overt image contains codes that belong to the proposed encoding method or not; type codes are used to judge the encoding type; tracing codes are used to judge the encoding trace; dimension codes are used to judge the size of the hidden information; and information codes are used to decode the hidden information. Applying the proposed encoding method is rather easy, and host images corresponding to overt images are not needed for decoding work. The experiment has demonstrated four types of encoding for the proposed encoding method to reconstruct covert images without any distortion or only with a little distortion.     

一种公钥算法密码卡的实现技术

密码卡是网络信息安全系统中基本而又非常重要的一部分,实现安全的密钥管理是密码卡的主要目的。本文主要介绍了一种安全的、实用性强的公钥算法密码卡的实现。     

一种高安全性的数字图像加密算法

提出了一种新的高安全性的数字图像置乱加密算法。该算法变换过程中可以通过密钥进行控制．安全程度仅取决于密钥的长度，避免了Arnold等其它置乱加密算法安全性不高的缺点；该算法变换速度快．几次变换就可以达到很好的置乱效果，在信息隐藏和数宇水印中有很大的实用价值。还给出了一种新的置乱程度的评价标准。