after the quantization step in jpeg compression standard. It is based on decomposed application, if encryption and watermark are commutative, some computational .. fingerprint embedding and decryption for video distribution,” IEEE. 1 1 Commutative Encryption and Watermarking in Video Compression Ieee Transactions On Circuits And Systems For Video Technology, Vol. 17, No. 6, June. 1 1 Commutative Encryption and Watermarking in Video Compression 交換式 加密及浮水印法應用在視頻壓縮 IEEE Transactions on Circuits and Systems for.

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Therefore, it has been proposed in [ 16 ] to change the secret parameters in every iteration of the Cat Map. We present a scheme for commutative watermarking-encryption CWE of audio data and demonstrate its robustness against an important class of attacks, Time-Scale Modifications TSM. Alice now generates some secret permutation and publishes along with a random graph having nodes and.

The presented CWE scheme is not fully commutative in theory because of the padding needed in the encryption step: In particular, if such a copy is detected, the Dispute Resolve Protocol must be able to identify as the rightful owner of and to identify as the offending party. The need for ivdeo CWE scheme becomes obvious in steps 3 and 4where an encrypted media object is watermarked and the presence of a watermark is verified comnutative an encrypted object, respectively.

Let the audio signal consist of a set of sample values. If these copies are marked with the identifier of some specific customerthe distributor can repudiate having generated the copies and the customer could be held responsible for the offence of.

Commutative Watermarking-Encryption of Audio Data with Minimum Knowledge Verification

Subscribe to Table of Contents Alerts. If is not a square number, the signal is padded with random sample values having the same probability distribution i. Here, we make a few modifications to this protocol to work with the proposed audio watermarking algorithm. Note, however, that there are only different keys.

In [ 18 ] the authors investigated the security of permutation ciphers as applied to images with greyvalues and found that if plaintexts are known, attacks with a complexity are possible, requiring frequent key updates.

To the best of our knowledge, no CWE schemes for audio data have been proposed so far.


If encryption and watermarking do commute, com;ression combination can serve as an important building block within a Digital Rights Management DRM System, as detailed further in Section 2. Assuming compresssion, in each pair, the first bin comes from a different part and second bin is chosen in a distance from the first, there are possibilities to choose a single bin pair.

The audio files include artificially generated signals as well as speech, single instruments, and pop music https: Two-dimensional permutations of the square grid can be quickly generated by repeated application of the Cat Map. Robustness against TSM attacks with and. The invariant feature commufative is therefore represented by the image histogram and a histogram-based algorithm can be used to embed the mark.

In addition, watermarks are embedded into the media watermarkiing to have an additional layer of protection which is present even after the data have been decrypted. Section 5 provides experimental results on the robustness and fidelity of the watermarking part. The histogram part leading to the minimum dissimilarity is used to extract the remaining bits from.

We divide the bins into equal parts of size. From encryptioon host of existing audio watermarking methods see [ 12 ] for an overviewthe method by Xiang et al. Then she computes and. Digital Signal Processing, Vol. In our opinion, this protocol, while being very ingenious, has two drawbacks: Bit error rates of extracted 56 bit watermarks after various StirMark attacks on seven example audio files.

Advances in Multimedia

For example, cloud computing clients need to secure their data, not only to protect their data from public attacks, but also to protect their data from their cloud service provider [ 7 ].

The discrete Cat Map is a two-dimensional map defined on a square grid by where and are parameters that can serve as the secret key if the function is used for encryption purposes. Published by Emory Hines Modified over 2 years ago. Audio Ciphering Methods Let commutaative audio signal consist of eencryption set of sample values.

From the left-hand side of 1 it is clear that the watermarking function comprsesion be able to act in the encrypted domain, which means that only a limited set of audiovisual features if any is available to the embedder and can be used to embed the mark.

Moreover, as a TSM attack may change the height relation of two histogram bins if only bins which are sufficiently different are selected for swapping, that is, should hold, comjutative is a strength parameter governing the robustness of the scheme. In general, the robustness is quite sensitive to the choice of parameters. Conclusions and future work. The following experiments were carried out with a collection of audio files provided by the European Broadcast Union EBU for sound quality assessment.


By introducing some modifications into an earlier interactive verification protocol, it was possible to fit the watermarking encryptoon defined here into an interactive verification protocol with minimum knowledge verification, that is, without disclosure of the watermark or the watermarking key.

Common bit depths for representing audio are 16, 20, or 24 bit. If you wish to download it, please recommend it to your friends in any social system. Concepts, Methodologies, Tools, and Applicationsvol. Its Structural ComplexitySpringer, More generally, it should be possible to protect multimedia data throughout the distribution chain in a flexible way by allowing the encryption and watermarking operations to commute [ 6 ].

Figure 3 shows the PSNR between original file and marked file for increasing length of the watermark and seven example soundfiles. She marks the cover work with the watermark using the algorithm described in Section 4.

Impact of different parameter choices on perceptibility. In resample mode, certain audio samples are repeated or removed in order to stretch or extend the time axis. Generate another random numbersuch that and. Each step consists of the following substeps: The basic problem here is that has access to the marked object in plaintext.

The invariant encryption approach to CWE as introduced in [ 1 ] is to encrypt the media data completely as opposed to the partial encryption approach, vodeo leaves part of the data encrtption to host the watermarkbut to use a weaker cipher that leaves a feature space of the media data invariant.

Proposed watermarking and encryption scheme. In [ 11 ], however, a permutation cipher is used to permute the sample values in the time domain, thereby keeping the histogram invariant. As in Craver and Katzenbeissers original protocol, the prover Alice generates a secret permutation and a graph.