| With the network mobile communication technology's development, popularizes gradually based on the graph and the zone bit code commercial aviation electron ticket clerk's in mobile termination transmission, thus enables the commercial aviation electron bill to be able by even more quickly with the convenience form dissemination and the payment. This service while relies on motion network convenient, also grew many security aspect question. For instance, the bill confirmation and ticket clerk's safe transmission question. At present, already could apply in the graph digital watermark algorithm this technology in the electronic ticket clerk domain, thus solves the related security aspect problem.The digital watermark technology does one of for information hiding technologies, is the data which needs through certain method increases to the carrier data, and may momentarily examine. The watermark specification in does not destroy the carrier data under the normal use premise, increases to the carrier in the information, this is the stealth, simultaneously to adapt each kind of demand carrier data to be advantageous for processing and the transmission after the compression. Carries on the weight between the transparency and robustness is one of digital watermark key technologies, In order to satisfy certain robustness, avoids because of the common signal processing, harms the compression and so on to cause the watermark the loss, Then should increase the big watermark energy to the primitive image low frequency part; On the other hand, to enhance the transparency, should increase the big watermark energy to the primitive image high-frequency unit, but usually concentrates in the low frequency scope image majority partial energies, because of processing and so on quantification loses very easily inserts to the high frequency watermark.What this article studies is one kind inserts the watermark to the commercial aviation electron passenger ticket intermediate frequency strip watermark technology, This can good reflection watermark robustness and the transparency. The sensitive data faces in view of the commercial aviation electron ticket clerk system in is being tampered with and the information revelation danger, In order to protect the legal advantage which both sides trade, the utilization is separated -odd the string to transform DCT (Discrete Cosine Transform) the digital watermark technology to realize based on the digital watermark electronic bill authentication system, The specific measures include: Watermark arrangement, DCT piecemeal, image intermediate frequency coefficient reorganization, watermark inserting, DCT inverse transformation extraction watermark.This article tests through produces several 500 watermark images to carry on the similar examination experiment stochastically, The result indicated that the correct watermark SM (similar measurement) is bigger than other illegal watermarks (illegal watermark SM is smaller than completely obviously 0 .2); Moreover, this algorithm before the watermark is inserted carries on the pseudo-random arrangement and with the primitive image related two arrangements, can resist the third party attempt to eliminate the watermark well through the cutting image important part the attack, From the result which withdraws may see, withdraws the watermark image has been polluted freely by the noise, But does not affect the watermark design the identification, the corresponding similarity measures SM respectively to achieve 0 .98 (image to cut 1/8) and 0 .95 (image cuts 1/4). Obviously, the relatively primitive watermark image change is very small.At present, the home based on the digital watermark technology's research in the digital broadcast, compiled to change domains and so on prompt, copyright protection, multimedia authentication to obtain the widespread application. Along with the digital watermark technology's development and the related basic study frame's formation, its application's domain and the scale will further also expand. |
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