Abstract: There are disclosed a system and method for preventing the leaking of digital content. The system for preventing the leaking of digital content may include a digital content layer generation unit for generating a digital content layer displaying digital content, a security layer generation unit for generating a security layer including security information based on information about a user terminal, and an information display unit for displaying the security layer generated by the security layer generation unit and the digital content layer generated by the digital content layer generation unit in the display device of the user terminal in an overlapping form so that the security information looks like overlapping with the digital content. Accordingly, the illegal leaking of digital content through photographing or screen capture can be prevented.

Abstract: The present invention relates to a virtual application program system, a storage device, a method of executing a virtual application program, and a method of protecting a virtual environment. The virtual application program system includes an execution control module for executing a virtual application program, and a virtual environment protection module loaded by the execution control module and configured to block non-permitted application programs from accessing a virtual environment accessed by the virtual application program. Accordingly, the virtual environment can be protected from a host application program, etc., and independency and security of a task using a virtual application program can be guaranteed.

Abstract: Disclosed herein are a digital file encryption method, a digital file decryption method, a digital file processing apparatus, and an encryption format conversion apparatus. The digital file encryption method includes encrypting a file using specific encryption information, storing the encrypted file in a file system, and storing the encryption information in a stream provided by the file system. Accordingly, since file lengths before and after encryption are identical to each other, an application needs not to consider a header length or perform offset correction when using an encrypted file.

Abstract: Disclosed herein are a digital information security system, a kernel driver apparatus, and a digital information security method. The digital information security system includes a user module configured to operate in a user mode and to provide environment setting information comprising policy information about a use of digital information, and a kernel driver configured to operate in a kernel mode, to acquire information generated by an application of the user mode for the use of digital information, and to perform rights control regarding the use of digital information based on the acquired information and the policy information. Accordingly, the construction of a security system can be simplified, and the security of a security system can be improved.

Abstract: The present invention relates to a method for embedding and detecting watermark wherein forgery/alternation of image can be identified and the location of forgery/alternation can be verified by embedding and detecting watermark into a digital image which is shot in real time. Watermark is generated by using a quantized coefficient after frequency transform used in the compression process. By embedding this into an image, image can be compressed simultaneously with embedding watermark. The present invention discloses a method for embedding robust watermark which embeds a random sequence circular shifted from an original pseudo random sequence by the distance d as watermark into an image. The present invention discloses a technology for generating and embedding watermark by using a DCT coefficient quantized during the process for MPEG compressing the image, wherein said watermark can be generated and embedded in a unit of macro blocks or slices.

Abstract: The object of the present invention is providing the apparatus and method for controlling playing and copying the digital audio contents by way of embedding the control code into and extracting the control code from the digital audio contents. To achieve the object of the invention, the present invention includes control code embedding apparatus which includes timing deciding part for distributing control code, control code embedding part and digital audio signal summing part, and control code extracting apparatus which includes distribution information collecting part, control code discerning part, and decoding/instruction generating part.

Abstract: The present invention relates to a method for embedding and detecting a watermark where a forgery/alternation of an image can be identified and the location of forgery/alternation can be verified by embedding and detecting a watermark into a digital image which is shot in real time. The watermark is generated by using a quantized coefficient after frequency transform used in the compression process. By embedding this into an image, the image can be compressed simultaneously with the embedded watermark. The present invention relates to a method for embedding a robust watermark which embeds a random sequence circular shifted from an original pseudo random sequence by the distance d as the watermark is embedded into an image, and a method for generating and embedding the watermark by using a DCT coefficient quantized during an MPEG compression process of the image.

Abstract: A method and system for verifying an electronic document and a system for providing an electronic document service are provided. The system for verifying the electronic document includes: an image data acquisition unit acquiring an image of the electronic document by scanning the electronic document; a barcode detection unit detecting a barcode inserted into a predetermined position in the acquired image of the electronic document and acquiring first electronic document data; an image data conversion unit generating second electronic document data by converting a format of the acquired image of the electronic document into a format that can be compared with the first electronic document data; a falsification determination unit determining whether the electronic document is falsified by comparing the first electronic document data with the second electronic document data; and a display unit displaying the fasification determination result determined by the falsification determination unit.

Abstract: By using a unique ID generated by considering the hardware characteristic of PC in PDA where an application program, etc. distributed based on PC is installed, it makes possible to generate and authenticate a virtual unique ID in PDA so as to authenticate drive of the application in PDA. As such, the file size of a distributed edition is small in its characteristic and it is difficult to have a protecting means such as security, etc. in view of the characteristic of device. Hence, illegal distribution is easy and a more certain solution is provided so as to prevent illegal copy of the application in PDA having a feasible characteristic in protecting copyright.

Abstract: Simultaneously with a robust watermark and fragile watermark or semi-watermark is embedded into conventional securities, etc., such as gift coupon, various kinds of ticket, coupon, electronic stamp, bond & debenture, note, stock certificate, lottery, paper money, check, etc. and various kinds of public documents including certificates, etc. requiring confirmation and authentication (hereinafter, referred to as “securities, etc.”) in the form of digital file. Such watermark-embedded securities, etc. are conveniently issued on-line and are printed out in the form of paper through a printer. The printed securities, etc. are used off-line and are authenticated by determining the forgery or alternation by means of photocopy, etc. through the detection of the embedded watermark.

Abstract: The present invention relates to apparatus and method for producing a document verifiable for its forgery or alteration, and apparatus and method for authenticating the document. A barcode is generated based on the information included in the document, and also watermark is generated based on the information included in the document. The generated barcode and watermark are combined, and the combined barcode and watermark are inserted in the document so as to produce the document. When authenticating the document, the document is detected so as to extract the barcode inserted in the document and the information included in the extracted barcode and the information included in the document are compared, and also the document is detected so as to extract the watermark inserted in the document and the information included in the extracted watermark and the information included in the document are compared.

Abstract: Provided is a digital information storage system, a digital information security system, and a digital information storing method, and a digital information providing method, and more particularly, to a digital information storage system including: a shared storage containing unique hardware information; and one or more user terminals interoperating with the shared storage through a network, encrypting digital information by using the hardware information of the shared storage and storing the encrypted digital information in the shared storage, and decoding the encrypted digital information by using the hardware information while loading the stored digital information. Accordingly, digital information is encrypted by using hardware information of a shared storage. The digital information can be thus protected from leakage caused by an illegal copy or the like.

Abstract: A watermark is embedded in spatial domain. However, the same effect as the watermark is embedded in frequency domain is obtained by inverse frequency transforming the watermark, and then embedding it. By doing that, robustness of the watermark is enhanced in comparison with conventional method for generating a watermark and adding it in spatial domain. Also, the watermark can be detected, even though an image is passed through stirmark, by enlarging the size of the watermark generated by inverse frequency transforming through re-sampling. In detecting the watermark, by high frequency filtering the watermarked image and getting all blocks of the watermarked image together, the effect of removing image component is obtained. Thereby, the detection speed of the watermark is improved, and the detection rate is increased as well.

Abstract: For the purpose of designing watermark to be robust against image modification such as geometric modification (rotating, cutting, enlarging/shrinking, etc.), compression, and blurring, the watermark is embedded in frequency domain after formed as 2 dimensional shape, for example radial or concentric shape. In detecting watermark, it is possible to effectively detect the watermark, by using relation to a generated watermark in case where the peak is detected.

Abstract: The present invention relates to a digital image watermarking apparatus and method. Luminance component of a digital image are transformed into coefficients of a frequency domain, and watermark is generated by encrypting a user key and generating pseudo random number from encrypted user key. Then, a replacement coefficient generated from a coefficient of a first frequency area and the watermark is replaced with a coefficient of a second frequency area so that the watermark is embedded into the digital image. The embedded watermark is extracted at an authenticating apparatus and the digital image is authenticated by finding the correlation between the extracted watermark and watermark for authentication.

Abstract: A method for embedding and detecting watermark by a quantization of a characteristic value of a signal is disclosed. In order to embed watermark, first, a signal which will be watermarked is segmented in a predetermined time period, and a characteristic value with regard to a signal within the frame obtained therefrom is evaluated in a predetermined manner. Quantized values within a set corresponding to a value of pattern information embedded into the frame among a plurality of sets including one or more quantized value respectively is compared with each characteristic value so as to determine a quantized value closest to the characteristic value. The intensity of insertion used for modifying the signal within the frame in order to make the characteristic value same as the determined quantized value is evaluated, and the signal within the frame is modified based on the evaluated intensity of insertion. The watermark detection is performed in a similar process as the embedment.

Abstract: The present invention relates to a method for embedding a watermark into a black and white or color digital image [D(x)]. Basically the inventive method comprises the steps of transforming the digital image using a wavelet transform [WC(y)], transforming a watermark using discrete cosine transform (DCT), integrating the wavelet-transformed digital image with the DCT-transformed watermark [DW(x)+WC(y)] to insert the watermark into the image, and generating the watermarked image using inverse wavelet transform [D(x)?]. For color images, RGB mode is converted into YIQ mode using a conversion matrix and the wavelet transform is applied to the Y-, I-, Q-values. This inventive digital watermarking of a color image is found to be highly robust against lossy compression and other image processing operations, compared to conventionally known methods which are known to be unsuitable for watermarking color images.

Abstract: The present invention relates to a method and apparatus for authenticating various types of digital certificates by using a text embedding method. The execution of the present invention is divided into two case, one case including images in the certificate and another case not including the images in the certificate, according to the characteristics of the certificate. In the former case, a text embedding method is applied to images included in the certificate to embed a series of information text (a specific number of the certificate, and issuing organization, name of a person in charge, etc.) designated by a person who issues the certificate into the images. In the latter case, there is generated an image imperceptible to the human eve but having the same color as the ground color certificate.

Abstract: Digital watermarking of digital audio is performed by Fourier transforming digital audio data, wavelet transforming the magnitude components of the Fourier transform coefficients of the digital audio data, discrete cosine transforming a watermark signal, multiplying the sign of the wavelet transform coefficients of the magnitude components to the coefficients of the discrete cosine transformed watermark signal, adding the coefficients of the Fourier transformed digital audio data and the adjusted discrete cosine transformed watermark signal, and inverse wavelet transforming the audio signal's coefficients before inverse Fourier transformation to finally generate watermark-embedded audio signal data.