探讨在"俄罗斯间谍案"秘密通信工作模型下,寻找可疑隐写载体的一种方案,为提取出隐藏的信息奠定基础。攻击者通过控守或经由安全部门获得可疑图像后,根据可疑图像上的水印确定相关网站,到相关网站上下载该网站所有具有相同尺寸的图像;由于经由原始图像到载密图像,除了经过隐写,还可能经过格式转换、二次压缩,而且载体与载密图像格式也可能不同,然而这些对图像像素的高比特位影响不大,因此将图像都转化为空域,根据设定的阈值筛选出可疑载体;根据常见隐写算法、隐写软件的隐写机制,提出判别规则,并根据判别规则识别所使用的隐写算法、隐写软件。
This paper presents a searching scheme for suspicious cover in secret communication of "Russian spies" and lays the foundation for extracting secret messages.The attackers can decide the web sites by watermarks in suspicious images after getting them through Security Division or network controlling,and download images of the same size.To turn cover images into stego images,besides steganography,images may be double compressed or format transformed,but the high bits of pixels are not affected.So when images are transformed to spatial format,the suspicious cover images can be recogniged with the threshold.Decision rules can be developed based on common steganographic algorithms or steganographic mechanisms.