Results 11  20
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23
Error Exponents for Channel Coding With Side Information,” presented at the Recent Results session
 IEEE Int. Symp. Info. Theory
, 2004
"... Capacity formulas and randomcoding and spherepacking exponents are derived for a generalized family of Gel’fandPinsker coding problems. These exponents yield asymptotic upper and lower bounds, respectively, on the achievable log probability of error. Information is to be reliably transmitted thro ..."
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Cited by 6 (4 self)
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Capacity formulas and randomcoding and spherepacking exponents are derived for a generalized family of Gel’fandPinsker coding problems. These exponents yield asymptotic upper and lower bounds, respectively, on the achievable log probability of error. Information is to be reliably transmitted through a noisy channel with finite input and output alphabets and random state sequence. The channel is selected by an hypothetical adversary. Partial information about the state sequence is available to the encoder, adversary, and decoder. The design of the transmitter is subject to a cost constraint. Two families of channels are considered: 1) compound discrete memoryless channels (CDMC), and 2) channels with arbitrary memory, subject to an additive cost constraint, or more generally to a hard constraint on the conditional type of the channel output given the input. Both problems are closely connected. In each case the randomcoding and spherepacking exponents coincide at high rates, thereby determining the reliability function of the channel family. The randomcoding exponent is achieved using a stacked binning scheme and a maximum penalized mutual information decoder. The spherepacking exponent is obtained by defining a dummy sequence whose joint type with the state sequence and channel input
Efficient provably secure public key steganography
, 2003
"... Abstract. We construct efficient public key steganographic schemes, without resort to any special existence assumption such as unbiased functions. This is the first time such a construction is obtained. Not only our constructions are secure, but also are essentially optimal and have no error decodin ..."
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Cited by 5 (0 self)
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Abstract. We construct efficient public key steganographic schemes, without resort to any special existence assumption such as unbiased functions. This is the first time such a construction is obtained. Not only our constructions are secure, but also are essentially optimal and have no error decoding. We achieve this by designing a new primitive called Pcodes.
Order Estimation for a Special Class of Hidden Markov Sources and Binary Renewal Processes
 IEEE Trans. Inform. Theory
, 2002
"... We consider the estimation of the order, i.e., the number of hidden states, of a special class of discretetime finitealphabet hidden Markov sources. This class can be characterized in terms of equivalent renewal processes. No a priori bound is assumed on the maximum permissible order. An order est ..."
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We consider the estimation of the order, i.e., the number of hidden states, of a special class of discretetime finitealphabet hidden Markov sources. This class can be characterized in terms of equivalent renewal processes. No a priori bound is assumed on the maximum permissible order. An order estimator based on renewal types is constructed, and is shown to be strongly consistent by computing the precise asymptotics of the probability of estimation error. The probability of underestimation of the true order decays exponentially in the number of observations while the probability of overestimation goes to zero sufficiently fast. It is further shown that this estimator has the best possible error exponent in a large class of estimators. Our results are also valid for the general class of binary independentrenewal processes with finite mean renewal times.
Capacity and randomcoding exponents for channel coding with side information
 IEEE Trans. Inform. Theory
, 2007
"... Capacity formulas and randomcoding exponents are derived for a generalized family of Gel’fandPinsker coding problems. These exponents yield asymptotic upper bounds on the achievable log probability of error. In our model, information is to be reliably transmitted through a noisy channel with finit ..."
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Cited by 5 (4 self)
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Capacity formulas and randomcoding exponents are derived for a generalized family of Gel’fandPinsker coding problems. These exponents yield asymptotic upper bounds on the achievable log probability of error. In our model, information is to be reliably transmitted through a noisy channel with finite input and output alphabets and random state sequence, and the channel is selected by a hypothetical adversary. Partial information about the state sequence is available to the encoder, adversary, and decoder. The design of the transmitter is subject to a cost constraint. Two families of channels are considered: 1) compound discrete memoryless channels (CDMC), and 2) channels with arbitrary memory, subject to an additive cost constraint, or more generally to a hard constraint on the conditional type of the channel output given the input. Both problems are closely connected. The randomcoding exponent is achieved using a stacked binning scheme and a maximum penalized mutual information decoder, which may be thought of as an empirical generalized Maximum a Posteriori decoder. For channels with arbitrary memory, the randomcoding exponents are larger than their CDMC counterparts. Applications of this study include watermarking, data hiding, communication in presence of partially known interferers, and problems such as broadcast channels, all of which involve the fundamental idea of binning. Index terms: channel coding with side information, error exponents, arbitrarily varying channels, universal coding and decoding, randomized codes, MAP decoding, random binning, capacity, reliability function, method of types, watermarking, data hiding, broadcast channels. This research was supported by NSF under ITR grants CCR 0081268 and CCR 0325924.
A Neyman–Pearson Approach to Universal Erasure and List Decoding
"... Abstract—When information is to be transmitted over an unknown, possibly unreliable channel, an erasure option at the decoder is desirable. Using constantcomposition random codes, we propose a generalization of Csiszár and Körner’s maximum mutual information (MMI) decoder with an erasure option for ..."
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Abstract—When information is to be transmitted over an unknown, possibly unreliable channel, an erasure option at the decoder is desirable. Using constantcomposition random codes, we propose a generalization of Csiszár and Körner’s maximum mutual information (MMI) decoder with an erasure option for discrete memoryless channels. The new decoder is parameterized by a weighting function that is designed to optimize the fundamental tradeoff between undetectederror and erasure exponents for a compound class of channels. The class of weighting functions may be further enlarged to optimize a similar tradeoff for list decoders—in that case, undetectederror probability is replaced with average number of incorrect messages in the list. Explicit solutions are identified. The optimal exponents admit simple expressions in terms of the spherepacking exponent, at all rates below capacity. For small erasure exponents, these expressions coincide with those derived by Forney (1968) for symmetric channels, using maximum a posteriori decoding. Thus, for those channels at least, ignorance of the channel law is inconsequential. Conditions for optimality of the Csiszár–Körner rule and of the simpler empiricalmutualinformation thresholding rule are identified. The error exponents are evaluated numerically for the binary symmetric channel. Index Terms—Constantcomposition codes, erasures, error exponents, list decoding, maximum mutual information (MMI) decoder, method of types, Neyman–Pearson hypothesis testing, random codes, sphere packing, universal decoding. I.
The DataHiding Capacity of Image Sources
 IEEE Trans. Image Proc. Submitted
, 2000
"... An informationtheoretic model for image watermarking and data hiding is proposed in this paper. Recent theoretical results are used to characterize the fundamental capacity limits of image watermarking and datahiding systems. Capacity is determined by the statistical model used for the host ima ..."
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An informationtheoretic model for image watermarking and data hiding is proposed in this paper. Recent theoretical results are used to characterize the fundamental capacity limits of image watermarking and datahiding systems. Capacity is determined by the statistical model used for the host image, by the distortion constraints on the data hider and the attacker, and by the information available to the data hider, to the attacker, and to the decoder. We consider autoregressive, blockDCT and wavelet statistical models for images and compute datahiding capacity for compressed and uncompressed hostimage sources. Closedform expressions are obtained under sparsemodel approximations. Models for geometric attacks and distortion measures that are invariant to such attacks are considered. Keywords  image watermarking, data hiding, minimax techniques, autoregressive processes, discrete cosine transform, wavelets, image modeling, information theory. EDICS Category : 5AUTH # Work presented in part at the IEEE International Conference on Image Processing, Vancouver, Canada, Oct. 2000. This research was supported by NSF grants MIP9707633 and CDA 9624396. + Corresponding Author: Tel +1 217 2448366, fax +1 217 2448371, email: moulin@ifp.uiuc.edu. 1 1
The multicast capacity of acyclic, deterministic relay networks with no interference
, 2005
"... The multicast capacity is determined for acyclic networks that have deterministic links with broadcasting at the transmitters and no interference at the receivers. Such networks were studied by M. R. Aref, and are here called Aref networks. The multicast capacity is shown to have a maxflow, mincu ..."
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Cited by 3 (1 self)
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The multicast capacity is determined for acyclic networks that have deterministic links with broadcasting at the transmitters and no interference at the receivers. Such networks were studied by M. R. Aref, and are here called Aref networks. The multicast capacity is shown to have a maxflow, mincut interpretation. This result complements existing theory for networks of directed channels, networks of undirected channels, and packet erasure networks. It is also shown that one cannot always separate channel and network coding in Aref networks.
Separation of channel and network coding in aref networks
 in ISIT
, 2005
"... Abstract — It is shown that one cannot always layer, or separate, channel and network coding for multicasting in deterministic relay networks with no interference. We call such networks Aref networks. The suboptimality of such layering in Aref networks is in contrast to the optimality of a similar l ..."
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Cited by 2 (0 self)
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Abstract — It is shown that one cannot always layer, or separate, channel and network coding for multicasting in deterministic relay networks with no interference. We call such networks Aref networks. The suboptimality of such layering in Aref networks is in contrast to the optimality of a similar layering in networks of discrete memoryless channels and certain networks of twoway channels. I.
On Achievable Error Exponents for Watermarking
 Proc. SPIE Conf
, 2005
"... Probabilityoferror exponents have recently been derived for watermarking systems based on spreadspectrum and quantizationindex modulation methods. This paper takes this work one step further and presents minmax error exponents for any embedding scheme and any attack (subject to distortion constr ..."
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Probabilityoferror exponents have recently been derived for watermarking systems based on spreadspectrum and quantizationindex modulation methods. This paper takes this work one step further and presents minmax error exponents for any embedding scheme and any attack (subject to distortion constraints) at all rates below capacity. The decoders used are universal: they do not know the attack used. Randomized codes outperform deterministic codes, except in the case of memoryless attacks where the same performance is obtained using either kind of code.
DETECTION AND INFORMATIONTHEORETIC ANALYSIS OF STEGANOGRAPHY AND FINGERPRINTING
, 2006
"... The proliferation of multimedia and the advent of the Internet and other public networks have created many new applications of information hiding in multimedia security and forensics. This dissertation focuses on two of these application scenarios: steganography (and its counter problem, steganalysi ..."
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The proliferation of multimedia and the advent of the Internet and other public networks have created many new applications of information hiding in multimedia security and forensics. This dissertation focuses on two of these application scenarios: steganography (and its counter problem, steganalysis), and fingerprinting. First, from a detectiontheoretic perspective, we quantify the detectability of commonly used informationhiding techniques such as spread spectrum and distortioncompensated quantization index modulation, and also the detectability of blockbased steganography. We devise a practical steganalysis method that exploits the peculiar block structure of blockDCT image steganography. To cope with the twin difficulties of unknown image statistics and unknown steganographic codes, we explore image steganalysis based on supervised learning and build an optimized classifier that outperforms previously proposed image steganalysis methods. Then, from an informationtheoretic perspective, we derive the capacity and randomcoding error exponent of perfectly secure steganography and public fingerprinting. For both games, a randomized stackedbinning scheme and a matched maximum penalized mutual information decoder are used to achieve capacity and to realize a randomcoding error exponent that is strictly positive at all rates below capacity.