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![]() Technology PhotoWaterMark represents a combination of the steganographic approach of concealment and the cryptographic approach of enciphering of data that provides practical impossibility of breaking. And, the basic inconvenience for breaking consists in analog representation of hidden data. The essence of the steganographic approach consists in concealment of the fact of transfer or introduction of the information in the carrier. One of such methods of [3, 4] - Holographic approach to embedding ... of the latent watermarks in photos is put in a basis of the present technology. It is established that a Fourier transformation of watermarks embedded in the frequency domain with a shift relative to the coordinate origin is a digital Fourier hologram. Or otherwise speaking, embedding of a watermark in an image spectrum, it is equivalent to embedding of a watermark the hologram in the image. ![]() The photoimage is read by the CCD-scanner, is exposed to transformations for detection of a hidden watermark, and then the watermark is shown on the monitor. In figure, the watermark is submitted as a mark copyright ©. ![]() For realization of return procedure, i.e. procedure of restoration of a watermark from the hologram, it is enough to execute two-dimensional transformation Fourier, if parameters of synthesis of the hologram, and in particular spatial carrier are certainly known. In real time, this function is realized by means of digital signal processors (DPS). For example, DSP firms Texas Instruments, allow to execute this procedure for shares of second. During restoration of a watermark, it is possible to observe both the restored object, and its holographic image: ![]() The major element of any information system is enciphering the confidential information. The considered approach is not exception - two-dimensional cryptograms are integrally built in a chain of transformations of two-dimensional images: ![]() Stability of the code is defined exclusively by stability of a confidential key. Thus, analog execution of means of protection of object of identification (a photo of the owner) and the latent character of built in data represents "poorly attractive" object for digital breaking, and attach of a cryptographic subsystem to the steganographic system of concealment of data provides a powerful barrier to not authorized intervention.
At a stage of working off of algorithms researches on embedding of the latent watermarks in carriers on a paper and plastic basis have been conducted. These researches are presented on page Results of experiments... and Experiments to restore HWM from art reproductions on paper carriers. The special software is developed for carrying out of experiments, allowing to change level of stability to influence of procedures of a photo printing and scanning by means of factor of strengthening of a signal of a watermark: a software package the Photographic watermark.
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R e f e r e n c e s: 1. "Successful breaking of the prototype of the RFID-passport (russian)": iXBT 2. The electronic passport: the microchip is not protected from a fake. // the Computer newspaper [russian] 3. M. V. Smirnov, "Holographic approach to embedding hidden watermarks in a photographic image," J. Opt. Technol. 72, 464-468 or http://jot.osa.org/abstract.cfm?id=85832 or [russian, PDF file] 4. M. V. Smirnov. "The holographic approach to embedding the latent water marks in the photos: "HOLOGRAPHY EXPO-2005" II-th international Forum, 27-29 Sep. 2005, Moscow. Report thesis, p. 43 5. "The latent transfer and storage of the confidential information on the Internet and cellular communication" 6. Results of experiments of embedding of the latent watermarks in facsimiles on a paper and plastic basis. 7. Experiments to restore HWM from art reproductions on paper carriers ("print-scan" process) |