Efficient construction of provably secure steganography under ordinary covert channels  

作　　者：ZHU Yan YU MengYang HU HongXin AHN Gail-Joon ZHAO HongJia 

机构地区：[1]Beijing Key Laboratory of Internet Security Technology,Peking University,Beijing 100871,China [2]Institute of Computer Science and Technology,Peking University,Beijing 100871,China [3]School of Mathematical Sciences,Peking University,Beijing 100871,China [4]School of Computing,Informatics,and Decision Systems Engineering,Arizona State University,Tempe,AZ 85287,USA

出　　处：《Science China(Information Sciences)》2012年第7期1639-1649,共11页中国科学（信息科学）（英文版）

基　　金：Zhu Yan,Yu Mengyang,and Zhao Hongjia was supported by National Natural Science Foundation of China (Grant Nos. 61170264, 10990011);Ahn Gail-Joon and Hu Hongxin were partially supported by US National Science Foundation (Grant Nos. NSF-IIS-0900970, NSF-CNS-0831360);Department of Energy (Grant No.DE-SC0004308)

摘　　要：Steganography is the science of hiding information within seemingly harmless messages or inno- cent media. This paper addresses the problems of efficient construction of secure steganography in ordinary covert channels. Without relying on any sampling assumption, we provide a general construction of secure steganography under computational indistinguishability. Our results show that unpredictability of mapping function in covertext sampler is indispensable for secure stegosystem on indistinguishability against adaptive chosen hiddentext attacks. We completely prove that computationally secure steganography can be constructed on pseudorandom function and unbiased sampling function under ordinary covert channels, that is, its secu- rity is inversely proportional to the sum of errors of these two functions, as well as the legth of hiddentexts. More importantly, our research is not dependent upon pseudorandom ciphertext assumption of cryptosystem or perfect sampling assumption. Hence, our results are practically useful for construction and analysis of secure stegosystems.Steganography is the science of hiding information within seemingly harmless messages or inno- cent media. This paper addresses the problems of efficient construction of secure steganography in ordinary covert channels. Without relying on any sampling assumption, we provide a general construction of secure steganography under computational indistinguishability. Our results show that unpredictability of mapping function in covertext sampler is indispensable for secure stegosystem on indistinguishability against adaptive chosen hiddentext attacks. We completely prove that computationally secure steganography can be constructed on pseudorandom function and unbiased sampling function under ordinary covert channels, that is, its secu- rity is inversely proportional to the sum of errors of these two functions, as well as the legth of hiddentexts. More importantly, our research is not dependent upon pseudorandom ciphertext assumption of cryptosystem or perfect sampling assumption. Hence, our results are practically useful for construction and analysis of secure stegosystems.

关 键 词：STEGANOGRAPHY CRYPTOGRAPHY INDISTINGUISHABILITY SAMPLER UNPREDICTABILITY adversary models 

分 类 号：TP301[自动化与计算机技术—计算机系统结构] TP393.08[自动化与计算机技术—计算机科学与技术]