Below in conjunction with accompanying drawing the present invention is further described.
Figure 1A represents an original seal image that does not add any information.Usually, seal image derives from digital picture scanning copy or other video generation device of image making software, general physics seal.Thisseal image 101 is guaranteed the habituation of people in use as the mother matrix of digital sealing.
Figure 1B represents the digital sealing image that comprises digital watermark information (being digital signature information) of digital sealing provided by the invention system.This digital sealing image 102 comprises two parts: first characterizes significant visible seal image, and the elementary identification function of seal is provided; Second portion is the digital signature information that is embedded in the image, is used for differentiating the true and false of document, judges its integrality, non-distorting property and legitimacy.
Fig. 1 C represents that the papery of the digital sealing image 102 of Figure 1Bduplicates version 103, and promptly digital sealing image 102 outputs to and obtains thisduplicatings editions 103 on the paper through printing (or printing) equipment.Digital sealing image 103 on the paper is the same with digital sealing image 102, also include two same parts: significant seal and the digital signature that is embedded in the seal, this illustrates that digital sealing provided by the invention system makes paper document also can differentiate the true and false of document by being embedded in digital signature in the seal, judges its integrality, non-distorting property and legitimacy.
Fig. 1 D represents other representation of digital sealing, and for example, the original image 104 of a people's signature is not adding any extraneous information, can do the sign effect of signature to file, and also as the mother matrix of digital sealing.
Fig. 1 E is the digital signature information that embeds document in the described original image 104 of presentation graphs 1D, and outputs to the seal image 105 on the paper through printing (or printing) equipment.The seal image 105 that includes digital signature except playing the sign effect of file signature, but also really has the true and false of differentiating document, judges functions such as its integrality, non-distorting property and legitimacy.
Fig. 2 is the document synoptic diagram with true and false authentication function that comprises the digital sealing part.As shown in the figure, document that comprises digital sealing of expression in the wire frame 210, the document comprises with the lower part:
(1) document content information 211;
(2) comprise digital sealing to 211 digital signature information of being done.
Digital sealing can be common common seal 212---the shape of seal is not limit (as circle, ellipse, rectangle, triangle etc.), the inner represented structure of seal is not limit (as company's seal, individual stamped signature etc.) yet, the seal content is not limit (if any " Axu Digit Technology Co., Ltd., Shanghai " printed words, or other unit printed words etc.);
Digital sealing also can be the handwritten signature image 215 that comprises digital signature.
Digital sealing can also be a Company Logo 213; The header of document/footer line 214; And digital watermarking bar code 215, these forms of expression are that 02110959.1 Chinese patent is open at application number, are not describing in detail here.
Fig. 3 A is that digital sealing of the present invention system produces one and comprises the electronic document of digital sealing or the synoptic diagram of paper document copy.This system comprises:
(1) the document content extraction element 311 of original document 310;
(2) the digital signature generating apparatus 313 of making document content digital signature;
(3) access control apparatus 315 of original seal image;
(4) the digitalwatermarking flush mounting 316;
(5) the digital sealing adding apparatus 318;
(6) paper document of the document 319 of electronic form duplicates the print control unit 322 and the print-out device 321 of (copy).
Wherein, in the system of reality, document content extraction element 311, digital signature module 313,watermark flush mounting 316, according to tick lables original document additional character seal module 318 and printout module 320 and printing control model 322 have been constituted one and add a cover digital sealing device 300, it can an integrated device.And in actual applications, modular integrating device 300 can directly generate the document of adding a cover digital sealing of electronic form or paper-based form behind input original document, original seal image, access control information and key.
Key 312, original seal image 314, seal access control apparatus 315 and seal access control information 317 can be integrated in the E-Intelligent key 301 of a USB flash disk size, E-Intelligent key and the integrated exchanges data of adding a cover digital sealing device 300 can be finished (as USB, serial ports, parallel port, infrared interface etc.) by communication interface commonly used, but they also can be stored separately beyond the E-Intelligent key respectively.
Again referring to Fig. 3 A, the course of work that digital sealing provided by the invention system whole comprises document is as follows:
(1) input desires to add a cover the original document 310 of digital sealing;
(2) 311 pairs of original documents 310 of document content extraction element are handled, and the original document key content is extracted;
(3) the document key content of above-mentioned document content extraction element 311 extractions is input in the digital signature generating apparatus 313, and the key 312 that utilizes system authentication center (CA) to sign and issue, and adopts public key algorithm that document content is done digital signature.This algorithm is the disclosed technology of prior art.
(4) digital signature that signature creating device 313 is generated is input in the watermark flush mounting 316.Watermark flush mounting 316 obtains the control information from seal access control apparatus 315, determine whether to visit original seal image 314, if can, so in watermark flush mounting 316, digital signature is embedded algorithm by digital watermarking be embedded in the original seal image 314, output comprises the digital sealing of digital signature information.Wherein, the bianry image digital watermarking algorithm that is adopted in the watermark flush mounting 316, its algorithm steps and ins and outs are open in 01132372.8 the Chinese patent application " a kind of digital anti-fake method " at application number, no longer describe here.
(5) tick lables that provides according to the user is attached to digital sealing in digital sealing adding apparatus 318 on the specified documents of original document, forms the document of adding a cover digital sealing, and output comprises the document 319 of the electronic form of digital sealing.
(6) according to practical application needs or customer requirements, print-out device 320 can print the paper copies of the document 319 of electronic form according to the output information of print control unit 322---comprise the document 321 of the paper-based form of digital sealing.
Can in multi-purpose computer, adopt software module to constitute, watermark flush mounting to those skilled in the art, also can adopt hardware to form.Fig. 3 B has provided the hard-wired structured flowchart of watermark flush mounting 316 among Fig. 3 A.This hardware comprises centralprocessing unit CPU 323, andstorage unit FLASH 324, dataperipheral interface units 326, and the embeddinghardware module 327 of digital watermarking.Receive original seal image 314 and the watermark information (being digital signature) that will embed by communication interface 325 (as USB, serial ports, parallel port etc.) commonly used; The seal image that comprises digital signature after will handling then sends it back computing machine or miscellaneous equipment bycommunication interface 325.
Fig. 4 A is the synoptic diagram of the authenticate device of the true and false of differentiating the electronic document comprise digital sealing and legitimacy.This authenticate device comprises: seal image extraction element 412, document content extraction element 411, watermark information extraction element 413 and digital signature authentication device 415.The course of work of this device is as follows:
(1) input contains the electronic document 410 of digital sealing;
(2) in seal image extraction element 412, the electronic document of input is handled, extract the seal image that comprises watermark (digital signature);
(3) in document content extraction element 411, the electronic document of input is handled, extract the document content that is subjected to legitimacy protection;
(4) in watermark information extraction element 413, the seal image of importing is carried out watermark information (digital signature information) extract, and export the digital signature information that extracts.Wherein, what adopted in the watermark information extraction element 413 is that the technology of bianry image digital watermarking algorithm is open in 01132372.8 the Chinese patent at application number, no longer describes here.
(5) key 414 signed and issued of digital signature authentication device 415 CA of receiving system authentication center, the digital signature information of in watermark information extraction element 413, extracting, the legal document content that in document content extraction element 411, extracts, carry out the checking of digital signature then, and the output result;
Certainly, seal image extraction element 412, document content extraction element 411, digital watermark information extraction element 413 and digital signature authentication device 415 constitute an electronic document demo plant 401, it can be integrated in the device, adopt this independent device, the user can provide the checking result behind the paper document 410 and key 414 of the checking of input desire.And it also both can be realized by software coding, also can adopt independent hardware unit or soft-hardware mix device to realize.
In addition, watermark information extraction element 413 can adopt software module to constitute in multi-purpose computer, also can adopt hardware to form.Fig. 4 B has provided the structural representation of the hardware implementation method of watermark extraction apparatus 413 among Fig. 4 A.This hardware comprises CPU (central processing unit) (CPU) 420, storage unit (FLASH) 421, data peripheral interface units 423, and the extraction hardware module 424 of digital watermarking.By the seal image that comprise watermark of communication interface 422 (as USB, serial ports, parallel port etc.) reception commonly used from seal image extraction element 412; Watermark information (digital signature) after will extracting then sends it back computing machine or miscellaneous equipment by communication interface 422.
Fig. 5 is the block scheme of authenticate device of the paper document that comprises digital sealing of digital sealing of the present invention system, and this device comprises: the automatic identification ofimage collecting device 511,image processing apparatus 512, Word message and manual input device/module 513, documentcontent extraction element 515,seal image extract 514, watermark information extraction element (module) 413 and digital signature authentication device 415.Its verification step is:
(1) input contains thepaper document 510 of digital sealing;
(2)image collecting device 511 utilizes image recording device (as video camera, scanner etc.) thatpaper document 510 is scanned in computing machine or other electronic equipment by general digital picture format (as JPEG, BMP etc.);
(3) the image scanning version of the paper document of 512 pairs of inputs of image processing module is carried out basic image pre-service, comprise denoising, rotation, change of scale, image recovery etc., and be partitioned into sub image section that comprises digital sealing and the sub image section that comprises Word message;
(4) the automatic typing of Word message and manual input device/module 513 receive the subimage that comprises Word message thatimage processing module 512 produces, be optical character identification OCR (Optical Character Recognition) and handle, automatically the Word message in the recognition image.For mistake, also can adopt the mode of manual typing that Word message is input in computing machine or the electronic equipment;
(5) sealimage extraction module 514 receives the subimage that comprises digital sealing thatimage processing module 512 generates, and it is done Flame Image Process such as further images match, Threshold Segmentation, output and the equirotal digital sealing image to be detected of original seal image;
(6) content discerned in the automatic typing of document content extraction element/module 515 reception Word messages and the literal that manual input device/module 513 transmits, and to its further extraction of doing information, obtain being subjected to the document content information of legitimacy protection;
(7) in watermarkinformation extraction element 516, the seal image of importing is carried out watermark information (digital signature information) extract, and export the digital signature information that extracts.Wherein, what adopted in thisdevice 516 is that the technology of bianry image digital watermarking extraction algorithm is open in 01132372.8 the Chinese patent at application number, no longer describes here.This device and watermark information extraction element 413 shown in Figure 4 can be same modules.
(8)key 517 signed and issued of digitalsignature authentication device 518 CA of receiving system authentication center, the digital signature information of extracting in 516, the legal document content that extracts in 515 carry out the checking of digital signature then, and the output result;
Wherein, the automatic identification ofimage collecting device 511, image processing apparatus/module 512, Word message and manual input device/module 513, sealimage extraction element 514, documentcontent extraction element 515, digital watermarkinformation extraction element 516 and digitalsignature authentication device 517 constitute a paperdocument demo plant 501, it also can be integrated a device 5, the user uses this isolated system,paper document 510 and key 517 in the checking of input desire can provide the checking result.
Fig. 6 represents that the present invention comprises the digital sealing system of digital sealing generation, transmission and authentication function, and this system comprises E-Intelligent key 301, adds a cover digital sealing system 300 on document, document transmission system 601, electronic document demo plant 401, paperdocument demo plant 501 and checking device displaying result 623.
From top description as can be known, digital sealing device 300 comprises document content extraction element 311, digital signature module 313, watermark flush mounting 316, according to tick lables to original document additional character seal module 318 and printout module 320 and printing control model 322, also can be an integrating device.Electronic document demo plant 401 comprises seal image extraction element 412, document content extraction element 411, digital watermark information extraction element 413 and digital signature authentication device 415 and constitutes.Paperdocument demo plant 501 comprises automatic identification and manual input device/module 513, sealimage extraction element 514, documentcontent extraction element 515, digital watermarkinformation extraction element 516 and the digitalsignature authentication device 517 ofimage collecting device 511, image processing apparatus/module 512, Word message.
Like this, it is as follows with the course of work that authenticates to comprise generation, the transmission of the electronics of digital sealing or paper document:
(1) input original document 310;
(2) sealing system 300 of digital sealing receives the information of original document 310 inputs, and according to information in the E-Intelligent key 301 and control function, operation determines whether to affix one's seal.If of course, system 300 exports the electronics or the paper document of adding a cover digital sealing so;
(3) electronic document information that receives of the sealing system 300 of digital sealing or paper document information are by document transmitting device 601 input electronic document demo plant 401 or paper document verification systems 501.Concrete, electronic document information arrives node 618 by the transmission node 614 of document transmitting device 601 through digital transmission (device) 616 (as Network Transmission).In addition, the information of paper document arrives node 619 by transmission node 615 through physical transfer (device) 617 (as surface mail, directly deliver etc.).Transmission course also can be mixed type (as a first digital transmission, in physical transfer, and then digital transmission etc.).
(4) from the electronic document that comprises digital sealing of node 618, be imported into the legitimate verification that carries out document in the electronic document demo plant 401.The paper document that comprises digital sealing from node 619 is imported into the legitimate verification that carries out document in the paper document verification system 501.Checking result output also shows in checking device displaying result 623, can determine the true and false of digital watermarking according to this result.
By top description, can find that extremely effect is as follows for the technical essential of digital sealing provided by the invention system:
1: having adopted the digital sealing technology, is that document is more practical
Digital sealing has the electronic document of discriminating and the paper document true and false and anti-tamper, anti-counterfeiting function.A digital sealing comprises:
(1) digital picture that can explicit existence on document or corresponding papery output copy.This image is explicit being present in electronic document or the paper document, and can be discerned by human eye and image acquisition component;
(2) be embedded in digital signature or other secure authenticated information in the image.Digital signature is the digital signature that adopts public key algorithm that document content is done.
Digital sealing both can be the digital picture that comprises digital signature information in the electronic document, also can be the papery output copy that comprises the digital picture of digital signature information.
2: the method and apparatus of on document, adding a cover digital sealing
Document comprises two notions, it had both represented to be present in the electronic document (as MS-WORD, WPS, EMAIL, html web page etc.) in computing machine or the electronic equipment, represented that also this electronic document process print out equipment (or printing equipment) outputs to the paper copies on the paper.
Add a cover digital sealing on document, its step comprises a lower part:
At first on document, add a cover digital sealing, need to determine the input parameter of system.The input parameter that needs comprises:
(1) is used to generate the original seal image (digital form) of digital sealing;
(2) be used to store the electronic storage device of original seal image, as hard disc of computer, USB dish, IC-card etc.;
(3) be used to control the device that original seal image is visited and digital sealing generates, definite who or what equipment of this device can be visited original seal image, and whether can start the digital sealing generator program.Control information derives from sealer's password, and biological characteristic (as fingerprint, iris, face picture etc.) or other are connected in the hardware device (as EKEY, IC-card, Dongle etc.) of this device.
(4) original electronic document;
(5) be used to generate the key of the digital signature of original electronic document, this key is the private key (Private Key) that adopts standard P KI system to sign and issue by system authentication center CA (Certificated Agent).
Secondly, top input parameter is input in the digital watermarking flush mounting by data transmission channel, and generates the digital sealing image of document.The digital sealing image has comprised the digital signature information of document, is output in the module of affixing one's seal through this device.
At last, the module of affixing one's seal is attached to the assigned address of document with the digital sealing image, generates the electronic document that digital sealing has been added a cover in also output.This electronic document can pass through printout (or printing) equipment, produces corresponding paper copies.
3: the true and false authentication method and the device of document
Discriminating comprises the document true and false authentication of digital sealing, and its device comprises: equipment, digital signature authentication equipment and output device are as a result extracted in the extraction equipment of document input equipment, document content and digital sealing image, digital watermarking.The input parameter that device needs comprises: original input document (electronics and papery), the sealer who signs and issues by CA or the PKI of unit, and the basic step of discrimination method is so:
(1) document input: for paper copies, then paper copies is carried out image acquisition, and the image of gathering is input in the authentication equipment at needs;
(2) the input document is carried out contents extraction and seal image extraction.
(3) in digital watermark detecting device, seal image is carried out watermark detection and extraction.
(4) document content and watermark are input in the digital signature authentication equipment, carry out the checking of digital signature, and the result is exported.