Patent•
Message authentication code using image histograms
02 Dec 1999-
TL;DR: In this article, a message authentication code is generated from the images of a received video stream, and if desired, compared with a digital watermark embedded in the video stream in order to confirm the accuracy of the video content or identify the source of a video stream.
Abstract: According to the principles of the invention, there is provided a system for generating a message authentication code for a conventional digital video stream. The system operates on the rows and columns of block data for a video stream, and more specifically on histograms of DC coefficients from each row and column, to produce a compact code that is nonetheless descriptive of the underlying images in the video stream. The message authentication code can be reproduced from the images of a received video stream, and if desired, compared with a digital watermark embedded in the video stream in order to confirm the accuracy of the video content or identify the source of the video stream.
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Patent•
15 Nov 2006
TL;DR: In this article, the authors present methods and systems for encoding digital watermarks into content signals, including window identifier for identifying a sample window in the signal; an interval calculator for determining a quantization interval of the sample window; and a sampler for normalizing sample window to provide normalized samples.
Abstract: Disclosed herein are methods and systems for encoding digital watermarks into content signals. Also disclosed are systems and methods for detecting and/or verifying digital watermarks in content signals. According to one embodiment, a system for encoding of digital watermark information includes: a window identifier for identifying a sample window in the signal; an interval calculator for determining a quantization interval of the sample window; and a sampler for normalizing the sample window to provide normalized samples. According to another embodiment, a system for pre-analyzing a digital signal for encoding at least one digital watermark using a digital filter is disclosed. According to another embodiment, a method for pre-analyzing a digital signal for encoding digital watermarks comprises: (1) providing a digital signal; (2) providing a digital filter to be applied to the digital signal; and (3) identifying an area of the digital signal that will be affected by the digital filter based on at least one measurable difference between the digital signal and a counterpart of the digital signal selected from the group consisting of the digital signal as transmitted, the digital signal as stored in a medium, and the digital signal as played backed. According to another embodiment, a method for encoding a watermark in a content signal includes the steps of (1) splitting a watermark bit stream; and (2) encoding at least half of the watermark bit stream in the content signal using inverted instances of the watermark bit stream. Other methods and systems for encoding/decoding digital watermarks are also disclosed.
603 citations
Patent•
03 Jan 2007
TL;DR: In this article, a method for applying a digital watermark to a content signal is described, and a watermarking key is identified, which includes a binary sequence and information describing application of that binary sequence to the content signal.
Abstract: A method for applying a digital watermark to a content signal is disclosed. In accordance with such a method, a watermarking key is identified. The watermarking key includes a binary sequence and information describing application of that binary sequence to the content signal. The digital watermark is then encoded within the content signal at one or more locations determined by the watermarking key.
454 citations
Patent•
04 Jun 2012
TL;DR: In this paper, the authors present methods and systems for transmitting streams of data, and also relate to generating packet watermarks and packet watermark keys, and an electronic method and system for purchasing good and services by establishing an account whereby a customer is credited with a predetermined amount of bandwidth usage.
Abstract: Disclosed herein are methods and systems for transmitting streams of data. The present invention also relates to generating packet watermarks and packet watermark keys. The present invention also relates to a computerized system for packaging data for transmission to a user. The system may utilize computer code to generate a bandwidth rights certificate that may include: at least one cryptographic credential; routing information for the transmission; and, optionally, a digital signature of a certificate owner; a unique identification code of a certificate owner; a certificate validity period; and pricing information for use of bandwidth. The present invention also relates to an electronic method and system for purchasing good and services by establishing an account whereby a customer is credited with a predetermined amount of bandwidth usage, and then charges are assessed against the account in an amount of bandwidth usage which corresponds to the agreed upon purchase value for the selected item.
255 citations
Patent•
07 Dec 2000
TL;DR: In this paper, the authors proposed a system for enhancing trust in transactions, most particularly in remote transactions between a plurality of transactional parties, for instance a seller and buyer(s) of goods and/or services over a public computer network such as the internet.
Abstract: The invention discloses a system for enhancing trust in transactions, most particularly in remote transactions between a plurality of transactional parties, for instance a seller and buyer(s) of goods and/or services over a public computer network such as the internet. Trust is disclosed to be a multivalent commodity, in that the trust that is to be enhanced relates to information about the subject matter of the transactions (e.g., the suitability of the goods and services sold), the bona fides of the supplier of the goods and services, the appropriateness of a pricing structure for a particular transaction or series of transactions, a quantum of additional transactional value that may be imparted to the transactional relationship, security of information exchange, etc. An important contributor to trust for such aspects of the transaction is disclosed to be the use of highly-secure steganographic computer processing means for data identification, authentication, and transmission, such that confidence in the transaction components is enhanced. By providing an integrated multivalent system for enhancing trust across a variety of categories (for a variety of transaction species, including those in which the need for trust is greater on the part of one party than of another, as well as those in which both require substantial trust enhancement), the invention reduces barriers to forming and optimizing transactional relationships.
247 citations
Patent•
22 Apr 2014
TL;DR: In this paper, a fast Fourier transform is used to transform digital blocks in digital information to the frequency domain using a convolution mask from a key, and the chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
Abstract: Multiple transform utilization and applications for secure digital watermarking. In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
177 citations
References
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TL;DR: The digital signature standard (DSS) as mentioned in this paper was proposed to authenticate electronic mail messages by using modern cryptographic techniques to prevent the explosion of very capable personal computers from driving up the incidence of doctored photographs being passed off as truth.
Abstract: The trustworthy digital camera is an application of existing technology toward the solution of an evermore-troubling social problem, the eroding credibility of the photographic image. Although it will always be possible to lie with a photograph (using such time-honored techniques as false perspective and misleading captions), this proposed device will prevent the explosion of very capable personal computers from driving up the incidence of doctored photographs being passed off as truth. A solution to this problem comes from the proposed digital signature standard (DSS), which incorporates modern cryptographic techniques to authenticate electronic mail messages. >
502 citations
Patent•
Cray1
TL;DR: In this paper, a 32-bit digital signature is embedded into the x-and y-coordinates of motion vectors and a probabilistic coding procedure is developed to avoid problems that arise when fewer than 16 blocks and/or vectors can be coded in a frame.
Abstract: Method and apparatus for watermarking digital video material by embedding a digital signature. One embodiment of the system integrates the embedding procedure into a block-based compression scheme. In one embodiment, a 32-bit digital signature is embedded into the x- and y-coordinates of motion vectors. Since not all motion vectors are suitable for coding (with regard to objectionable visible artifacts), three hybrid selection criteria have been developed for determining whether or not to code a motion vector. A probabilistic coding procedure has also been developed to avoid problems that arise when fewer than 16 blocks and/or vectors (where 16 vectors correspond to 32 bits) can be coded in a frame. One such procedure makes use of binary random sequences to virtually code the signature into the motion vectors. The system has been implemented on a CRAY T3D massively parallel supercomputer, where a near-real-time (5 frames per second) embedding of the signature is obtainable. The results show that it is possible to embed and retrieve a 32-bit signature if enough blocks over time are selected.
289 citations
Patent•
IBM1
TL;DR: In this paper, the authors propose a system consisting of a stamping process that embeds stamping information into a source image and produces a verification key, and a verification process that extracts stamping from a stamped source image based on the verification key.
Abstract: A system quickly verifies that the content of an image has not been changed since an earlier time when the content of that image was stamped. The system consists of a stamping process that embeds stamping information into a source image and produces a verification key, and a verification process that extracts stamping information from a stamped source image based on the verification key. Furthermore, the verification process produces an image itself, from which the verification can be readily judged visually or by use of a computer or other display device. In the verification process, the changes in an image can be detected and localized. The image stamping process further includes an error diffussion process so that the effects of combining the stamping information with the original image are not readily perceptable. An image is safeguarded against malicious manipulations and the proprietary rights are protected by maintaining the integrity of the image content.
255 citations
Patent•
NEC1
TL;DR: In this paper, a watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data into a set of n×n blocks, such as the 8×8 blocks of MPEG, and extracts the watermark from the summed block.
Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n×n blocks, such as the 8×8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8×8 blocks to form a set of N summed 8×8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain. Moreover, insertion of a watermark signal into image data and the subsequent extraction of the watermark from watermarked image data which has been subject to distortion between the times of insertion and extraction involves the insertion of multiple watermarks designed to survive predefined distortions of the image data, such as panscan or letterbox mode transformations. Alternatively, a registration pattern in the image data, after the image data containing the registration pattern is subject to an unknown distortion, is used to compensate for distortion of the watermarked image data.
251 citations
Patent•
26 Jan 1998TL;DR: In this paper, pixel blocks of an input image are type classified based on an analysis of pixel values for each respective pixel block, and a quantization modification process thresholds and/or quantizes the resulting DCT coefficients based on the type classification of the respective pixel blocks.
Abstract: Pixel blocks of an input image are type classified based on an analysis of pixel values for each respective pixel block. A discrete cosine transform (DCT) is performed on the pixel values of each pixel block, and a quantization modification process thresholds and/or quantizes the resulting DCT coefficients based on the type classification of the respective pixel block. Once the coefficients are modified in this way and encoded, the resulting data can be decoded and dequantized in compliance with the standard JPEG sequential mode data syntax in order to construct a perceptually faithful representation of the image, without passing any additional information to the decoder concerning the quantization modification.
145 citations