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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Introduction Video encryption and watermarking scheme based on H.
In order to apply them in the audio domain and in order to make the overall scheme more robust to TSM attacks, some modifications were necessary, which are described in the following paragraphs. Comparison of signal histograms. For example, a permutation cipher can be used for encryption, leaving the global first-order statistics of the image untouched. Figure 2 shows the effect of the Cat Map after five iterations on the waveform of an example signal.
Comparison of the first three seconds of signal waveforms. Note that if the histogram commutatige in are revealed, but not their order, as in the protocol described in Section 6.
Commutative Watermarking-Encryption of Audio Data with Minimum Knowledge Verification
Note that for the watermarking algorithm described here, the watermarking key consists of a list of bin pairs. Auth with social network: The need for a CWE scheme becomes obvious in steps 3 and 4where an encrypted media object is watermarked and the presence of a watermark is verified in an encrypted object, respectively.
Commutative watermarking-encryption CWE means watermarklng combination of znd and encryption in such a way that the encryption and watermarking functions commute; that is, where is the encryption function, is the encryption key, is the watermarking key, is the cleartext media data, and is the mark to be embedded.
Let the watermark consist of bits.
It is possible, however, to achieve certain robustness against a certain well-defined class of attacks, as the proposed algorithm shows.
Moreover, the ckmmutative by Xiang et al. Craver and Katzenbeisser go on to show that if these steps are repeated times, Alice has probability to fool Bob into believing that her watermark is contained in.
In resample mode, certain audio samples are repeated or removed in order to stretch or extend the time axis. The modified protocol now proceeds in steps. To make this website work, we log user data and share it with processors.
Advances in Multimedia
Applying these results to an audio file of length means that copmression plaintexts are sufficient to break the cipher, where is the number of possible sample values.
A serious drawback of water,arking protocol is the fact that publication of the permuted watermarking key reveals the bin pairs where the watermarking bits are embedded.
In this scenario, a number of attacks are possible, most importantly the case where sells a copy of in his own right.
In Section 4we present our CWE scheme in detail. This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Ecole polytechnique 5. Most existing audio ciphering methods like, for example, [ 9 ] or [ 10 compdession, substitute the audio sample values and change i. The watermarking bit is now embedded in the following way: The general idea is to permute the discrete points in time, while leaving the sample values untouched. In particular, if the number of histogram bins is further increased, the robustness decreases accordingly.
Audio Watermarking Methods From the host of existing audio watermarking methods see [ 12 ] for an overviewthe method by Xiang et al.
Having thus verified to be in possession of the correctBob goes on to compute and uses to extract from. The result is warermarking marked work. For these parameter choices, the proposed watermarking algorithm is extremely robust against TSM attacks in resample mode, while the robustness against pitch-invariant mode is slightly worse, but still very good. An obvious solution is that embeds a watermark identifying as the rightful owner into and provides the marked object to.
Note that the noncommutativity is not intrinsic to the overall scheme, but results from the special way the permutations are generated, namely, by deploying the two-dimensional discrete Cat Map.
The detector needs to know the original mean value of the samples of the unmarked cover workalong with the synchronization sequence sync of length and the sequence of bin pairs used for embedding the markwhich serves as a watermarking key. In addition, we show how the proposed CWE scheme can be integrated into a cryptographic protocol enabling public verification of the embedded mark without disclosing the mark or the watermarking key used for embedding.
Section 5 provides experimental results on the robustness and ij of the watermarking part. However, this procedure can imply a substantial change of the histogram mean.
Moreover, steps 3 and 4 call for a public key watermarking scheme, where there is a private embedding key and watermarkinf public detection key, or an asymmetric scheme, where it is possible to verify the existence of a watermark without fully disclosing the embedding key or the encrytion itself.
The advantage of the invariant encryption approach is that all media data are encrypted and not just a subset as in partial encryption schemes. The discrete Cat Map is a two-dimensional map defined on a square watermarikng by where and are parameters that can serve as the secret key if the function is used for encryption purposes.
He can check the correctness of by verifying the hashvalue in. Technological, Economic, Legal and Political Aspectsvol. The invariant feature space is therefore represented by the image histogram and a histogram-based algorithm can be used to embed the mark.
If is not a square number, the signal is padded with random sample values having the same probability distribution i.