A learning with error problem based encryption scheme that allows secure searching over the cipher text is proposed. Both the generation of cipher text and the trapdoor of the query are based on the problem of learnin...A learning with error problem based encryption scheme that allows secure searching over the cipher text is proposed. Both the generation of cipher text and the trapdoor of the query are based on the problem of learning with errors. By performing an operation over the trapdoor and the cipher text, it is able to tell if the cipher text is the encryption of a plaintext. The secure searchable encryption scheme is both cipher text and trapdoor indistinguishable. The probabilities of missing and failing match occurrence in searching are both exponentially small.展开更多
Information hiding in Joint Photographic Experts Group （JPEG） compressed images are investigated in this paper. Quantization is the source of information loss in JPEG compression process. Therefore, information hidd...Information hiding in Joint Photographic Experts Group （JPEG） compressed images are investigated in this paper. Quantization is the source of information loss in JPEG compression process. Therefore, information hidden in images is probably destroyed by JPEG compression. This paper presents an algorithm to reliably embed information into the JPEG bit streams in the process of JPEG encoding. Information extraction is performed in the process of JPEG decoding. The basic idea of our algorithm is to modify the quantized direct current （DC） coefficients and non zero alternating currenl （AC） coefficients to represent one bit information （0 or 1 ）. Experimental results on gray images using baseline sequential JPEG encoding show that the cover images （images without scoret information） and the stego-images （images with secret information） are perceptually indiscernible.展开更多
基金Supported by Self-directed Research Program of Tsinghua University (2011Z01033)
文摘A learning with error problem based encryption scheme that allows secure searching over the cipher text is proposed. Both the generation of cipher text and the trapdoor of the query are based on the problem of learning with errors. By performing an operation over the trapdoor and the cipher text, it is able to tell if the cipher text is the encryption of a plaintext. The secure searchable encryption scheme is both cipher text and trapdoor indistinguishable. The probabilities of missing and failing match occurrence in searching are both exponentially small.
文摘Information hiding in Joint Photographic Experts Group （JPEG） compressed images are investigated in this paper. Quantization is the source of information loss in JPEG compression process. Therefore, information hidden in images is probably destroyed by JPEG compression. This paper presents an algorithm to reliably embed information into the JPEG bit streams in the process of JPEG encoding. Information extraction is performed in the process of JPEG decoding. The basic idea of our algorithm is to modify the quantized direct current （DC） coefficients and non zero alternating currenl （AC） coefficients to represent one bit information （0 or 1 ）. Experimental results on gray images using baseline sequential JPEG encoding show that the cover images （images without scoret information） and the stego-images （images with secret information） are perceptually indiscernible.
