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Mohammad Reza Aref - One of the best experts on this subject based on the ideXlab platform.

  • Channel Simulation via Interactive Communications
    IEEE Transactions on Information Theory, 2015
    Co-Authors: Mohammad Hossein Yassaee, Amin Gohari, Mohammad Reza Aref
    Abstract:

    In this paper, we study the problem of channel simulation via Interactive communication, known as the coordination capacity, in a two-terminal network. We assume that two terminals observe independent identically distributed (i.i.d.) copies of two random variables and would like to generate i.i.d. copies of two other random variables jointly distributed with the observed random variables. The terminals are provided with two-way communication links, and shared common randomness, all at limited rates. Two special cases of this problem are the Interactive function computation studied by Ma and Ishwar, and the tradeoff curve between one-way communication and shared randomness studied by Cuff. The latter work had inspired Gohari and Anantharam to study the general problem of channel simulation via Interactive communication stated above. However, only inner and outer bounds for the special case of no shared randomness were obtained in their work. In this paper, we settle this problem by providing an exact computable characterization of the multiround problem. To show this we employ the technique of output statistics of random binning that has been recently developed by the authors.

  • Channel simulation via Interactive Communications
    arXiv: Information Theory, 2012
    Co-Authors: Mohammad Hossein Yassaee, Amin Gohari, Mohammad Reza Aref
    Abstract:

    In this paper, we study the problem of channel simulation via Interactive communication, known as the coordination capacity, in a two-terminal network. We assume that two terminals observe i.i.d.\ copies of two random variables and would like to generate i.i.d.\ copies of two other random variables jointly distributed with the observed random variables. The terminals are provided with two-way communication links, and shared common randomness, all at limited rates. Two special cases of this problem are the Interactive function computation studied by Ma and Ishwar, and the tradeoff curve between one-way communication and shared randomness studied by Cuff. The latter work had inspired Gohari and Anantharam to study the general problem of channel simulation via Interactive communication stated above. However only inner and outer bounds for the special case of no shared randomness were obtained in their work. In this paper we settle this problem by providing an exact computable characterization of the multi-round problem. To show this we employ the technique of "output statistics of random binning" that has been recently developed by the authors.

  • ISIT - Channel simulation via Interactive Communications
    2012 IEEE International Symposium on Information Theory Proceedings, 2012
    Co-Authors: Mohammad Hossein Yassaee, Amin Gohari, Mohammad Reza Aref
    Abstract:

    In this paper, we study the problem of channel simulation via Interactive communication, known as the coordination capacity, in a two-terminal network. We assume that two terminals observe i.i.d. copies of two random variables and would like to generate i.i.d. copies of two other random variables jointly distributed with the observed random variables. The terminals are provided with two-way communication links, and shared common randomness, all at limited rates. Two special cases of this problem are the Interactive function computation studied by Ma and Ishwar, and the tradeoff curve between one-way communication and shared randomness studied by Cuff. The latter work had inspired Gohari and Anantharam to study the general problem of channel simulation via Interactive communication stated above. However only inner and outer bounds for the special case of no shared randomness were obtained in their work. In this paper we settle this problem by providing an exact computable characterization of the multi-round problem. To show this we employ the technique of “output statistics of random binning” that has been recently developed by the authors.

Duane Varan - One of the best experts on this subject based on the ideXlab platform.

  • Modeling Self-Selection Bias in Interactive-Communications Research
    Communication Methods and Measures, 2012
    Co-Authors: Steven Bellman, Duane Varan
    Abstract:

    Interactive media use is a key issue in contemporary and future communication research. However, when users can interact with messages, new sources of variation emerge that make generalization difficult. This article introduces methods that communication researchers can use to increase the external validity of studies investigating the effects of interactivity versus noninteractivity. For this area of research, the article recommends the use of forced-interaction studies with random assignment to maximize internal validity, and free-interaction studies with self-selection bias modeling to maximize external validity. The article concludes with examples of self-selection bias modeling, using data from real studies, and a discussion of their implications for communication researchers.

Sujoy Roy - One of the best experts on this subject based on the ideXlab platform.

  • Secure Robust Hash Functions and Their Applications in Non-Interactive Communications
    Crime Prevention Technologies and Applications for Advancing Criminal Investigation, 2012
    Co-Authors: Sujoy Roy
    Abstract:

    A robust hash function allows different parties to extract a consistent key from a common fuzzy source, e.g., an image gone through noisy channels, which can then be used to establish a cryptographic session key among the parties without the need for interactions. These functions are useful in various communication scenarios, where the security notions are different. The authors study these different security notions in this paper and focus on forgery attacks, where the objective of the attack is to compute the extracted key (hash value) of a given message. This paper will examine information-theoretical security against forgery under chosen message attacks. The authors prove that it is not possible due to the entropy of the hash value of a given message can be reduced arbitrarily when sufficient message/hash pairs have been observed. In this regard, the authors give a computationally secure scheme, where it is computationally infeasible to compute the hash value even when its entropy may not be high.

  • Secure Robust Hash Functions and Their Applications in Non-Interactive Communications
    International Journal of Digital Crime and Forensics, 2010
    Co-Authors: Sujoy Roy
    Abstract:

    A robust hash function allows different parties to extract a consistent key from a common fuzzy source, e.g., an image gone through noisy channels, which can then be used to establish a cryptographic session key among the parties without the need for interactions. These functions are useful in various communication scenarios, where the security notions are different. The authors study these different security notions in this paper and focus on forgery attacks, where the objective of the attack is to compute the extracted key (hash value) of a given message. This paper will examine information-theoretical security against forgery under chosen message attacks. The authors prove that it is not possible due to the entropy of the hash value of a given message can be reduced arbitrarily when sufficient message/hash pairs have been observed. In this regard, the authors give a computationally secure scheme, where it is computationally infeasible to compute the hash value even when its entropy may not be high. be real-valued, e.g., M can be feature vectors extracted from images. Robust hash functions are very useful in secure non-Interactive Communications, where two or more parties wish to derive a session key from a common fuzzy source without interaction. Such a session key can then be used, for example, in identity verification or encryption. A typical application scenario of robust hash functions is the protection against copying attacks, where attackers attempt to copy a legitimate watermark from a marked multimedia object to an unmarked object (Kutter et al., 2000; Craver et al., 1998). In such scenarios, DOI: 10.4018/jdcf.2010100104 52 International Journal of Digital Crime and Forensics, 2(4), 51-62, October-December 2010 Copyright © 2010, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. we could use a watermark that is dependent on the content of the multimedia object. To achieve this, a robust hash function could be employed to extract a key from the given multimedia object, and then a watermark could be generated from the extracted key. In this case, the communication parties would be the watermark embedder and detector, where the multimedia object serves both as a communication channel and the common fuzzy source to generate the watermarking key. In this scenario, we would require that the hash function should be robust against the noise expected in the actual watermarking application, yet it should be difficult (if possible at all) to estimate this key generation process for an unmarked object. We note that the central part of the above security application is the extraction of the session key from the common fuzzy source. Therefore, in this paper, we are concerned with the more abstract key extraction scenario as illustrated in Figure 1. Suppose two parties A and B have access to some correlated random sources X and X ' respectively (e.g., X and X ' could be the picture of the same scene taken at different times of the day), and they wish to agree on a common (secret) session key based on their own random source without communication. In this case, a keyed robust hash function H() × can be applied to allow both parties to generate the same hash b using a shared keyK . This allows both to decide upon a session key that they can use to do various tasks without directly using their shared secret key or exchanging any information as required by common key agreement protocols. As we can see from Figure 1, if X is an original multimedia object, and X ' is a watermarked object obtained by embedding a digital watermark intoX , then the hash b that can be consistently extracted can be used to validate the authenticity of the multimedia object. Nevertheless, such a consistent string b can be used in many other scenarios, where it is desirable to extract a consistent key from noisy data. Despite the potentials of robust hash functions, it is often not easy to analyze the security. This is perhaps partly due to the complexity of the interactions among many different parameters, which affect the robustness and security (such as collision and forgery resistance), and partly due to the lack of clear threat and attack models. Roughly speaking, robustness of a robust hash function measures its tolerance to permissible noise, and collision resistance measures the difficulty of an attacker finding two dissimilar messages that yield the same hash value (more precise definitions will be given in later sections). In this paper, we study forgery resistance of robust hash functions (Swaminathan et al., 2006), which measures the difficulty for attackers to compute the hash value of a given message without knowing the secret key. Similar to settings used by Swaminathan et al. (2006), we first investigate information theoretical security measured by conditional entropy. However, instead of considering just one message X 1 and its hash b 1 , we consider chosen message attacks, where the attacker is allowed to Figure 1. Session key extraction 10 more pages are available in the full version of this document, which may be purchased using the "Add to Cart" button on the publisher's webpage: www.igi-global.com/article/secure-robust-hash-functions-

Mohammad Hossein Yassaee - One of the best experts on this subject based on the ideXlab platform.

  • Channel Simulation via Interactive Communications
    IEEE Transactions on Information Theory, 2015
    Co-Authors: Mohammad Hossein Yassaee, Amin Gohari, Mohammad Reza Aref
    Abstract:

    In this paper, we study the problem of channel simulation via Interactive communication, known as the coordination capacity, in a two-terminal network. We assume that two terminals observe independent identically distributed (i.i.d.) copies of two random variables and would like to generate i.i.d. copies of two other random variables jointly distributed with the observed random variables. The terminals are provided with two-way communication links, and shared common randomness, all at limited rates. Two special cases of this problem are the Interactive function computation studied by Ma and Ishwar, and the tradeoff curve between one-way communication and shared randomness studied by Cuff. The latter work had inspired Gohari and Anantharam to study the general problem of channel simulation via Interactive communication stated above. However, only inner and outer bounds for the special case of no shared randomness were obtained in their work. In this paper, we settle this problem by providing an exact computable characterization of the multiround problem. To show this we employ the technique of output statistics of random binning that has been recently developed by the authors.

  • Channel simulation via Interactive Communications
    arXiv: Information Theory, 2012
    Co-Authors: Mohammad Hossein Yassaee, Amin Gohari, Mohammad Reza Aref
    Abstract:

    In this paper, we study the problem of channel simulation via Interactive communication, known as the coordination capacity, in a two-terminal network. We assume that two terminals observe i.i.d.\ copies of two random variables and would like to generate i.i.d.\ copies of two other random variables jointly distributed with the observed random variables. The terminals are provided with two-way communication links, and shared common randomness, all at limited rates. Two special cases of this problem are the Interactive function computation studied by Ma and Ishwar, and the tradeoff curve between one-way communication and shared randomness studied by Cuff. The latter work had inspired Gohari and Anantharam to study the general problem of channel simulation via Interactive communication stated above. However only inner and outer bounds for the special case of no shared randomness were obtained in their work. In this paper we settle this problem by providing an exact computable characterization of the multi-round problem. To show this we employ the technique of "output statistics of random binning" that has been recently developed by the authors.

  • ISIT - Channel simulation via Interactive Communications
    2012 IEEE International Symposium on Information Theory Proceedings, 2012
    Co-Authors: Mohammad Hossein Yassaee, Amin Gohari, Mohammad Reza Aref
    Abstract:

    In this paper, we study the problem of channel simulation via Interactive communication, known as the coordination capacity, in a two-terminal network. We assume that two terminals observe i.i.d. copies of two random variables and would like to generate i.i.d. copies of two other random variables jointly distributed with the observed random variables. The terminals are provided with two-way communication links, and shared common randomness, all at limited rates. Two special cases of this problem are the Interactive function computation studied by Ma and Ishwar, and the tradeoff curve between one-way communication and shared randomness studied by Cuff. The latter work had inspired Gohari and Anantharam to study the general problem of channel simulation via Interactive communication stated above. However only inner and outer bounds for the special case of no shared randomness were obtained in their work. In this paper we settle this problem by providing an exact computable characterization of the multi-round problem. To show this we employ the technique of “output statistics of random binning” that has been recently developed by the authors.

Seung Chun Paek - One of the best experts on this subject based on the ideXlab platform.