The Experts below are selected from a list of 534 Experts worldwide ranked by ideXlab platform

Moti Yung - One of the best experts on this subject based on the ideXlab platform.

  • Key Evolution Systems in Untrusted Update Environments
    ACM Transactions on Information and System Security, 2010
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-Secure Signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer’s storage by evolving the private key in a one-way fashion. To simplify the integration of these primitives into standard security architectures, Boyen et al. [2006] recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages and not at update time (since update is not user-driven). The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. They also suggest the integration of untrusted updates in the Bellare-Miner forward-secure signature. Their work left open the problem of endowing other existing FSS systems with the same second factor protection, and a natural second question is whether the method can apply to other key-evolving paradigms. This article solves the first problem by showing an efficient generic construction that does not require to set a bound on the number of time periods at key generation. The article then extends the unprotected update model to other key-evolving primitives such as forward-secure public key encryption and key-insulated cryptosystems.

  • Inscrypt - Key Evolution Systems in Untrusted Update Environments
    Information Security and Cryptology, 2009
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Key-evolving protocols aim at limiting damages when an attacker obtains full access to the signer's storage. To simplify the integration of such mechanisms into standard security architectures, Boyen, Shacham, Shen and Waters suggested the construction of forward-secure signatures (FSS) that protect past periods after a break-in, with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of private keys so that passwords only come into play for signing messages. Boyen et al. described a pairing-based scheme in the standard model and also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature. They left open the problem of endowing other efficient FSS systems with the same second factor protection. We first address this problem and suggest generic ways to construct FSS schemes in untrusted update environments. In a second step, we extend the unprotected update model to other key-evolving systems such as forward-secure public key encryption and key-insulated cryptosystems. We then explain how some of the constructions that we proposed for forward-secure signatures can be adapted to these models.

  • Key evolution systems in untrusted update environments
    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    {Forward-Secure} Signatures {(FSS)} prevent forgeries for past time\nperiods when an attacker obtains full access to the signer{\textquoteright}s\nstorage by evolving the private key in a one-way fashion. To simplify\nthe integration of these primitives into standard security architectures,\nBoyen et al. [2006] recently introduced the concept of forward-secure\nsignatures with untrusted updates where private keys are additionally\nprotected by a second factor (derived from a password). Key updates\ncan be made on Encrypted Version of signing keys so that passwords\nonly come into play for signing messages and not at update time (since\nupdate is not user-driven). The scheme put forth by Boyen et al.\nrelies on bilinear maps and does not require the random oracle. They\nalso suggest the integration of untrusted updates in the {Bellare-Miner}\nforward-secure signature. Their work left open the problem of endowing\nother existing {FSS} systems with the same second factor protection,\nand a natural second question is whether the method can apply to\nother key-evolving paradigms. This article solves the first problem\nby showing an efficient generic construction that does not require\nto set a bound on the number of time periods at key generation. The\narticle then extends the unprotected update model to other key-evolving\nprimitives such as forward-secure public key encryption and key-insulated\ncryptosystems.

  • ACM Conference on Computer and Communications Security - Forward-secure signatures in untrusted update environments: efficient and generic constructions
    Proceedings of the 14th ACM conference on Computer and communications security - CCS '07, 2007
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-secure signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer's storage. To simplify the integration of these primitives into standard security architectures, Boyen, Shacham, Shen and Waters recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages. The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. The latter work also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature and left open the problem of endowing other existing FSS systems with the same second factor protection. This paper solves this problem by showing how to adapt the very efficient generic construction of Malkin, Micciancio and Miner (MMM) to untrusted update environments. More precisely, our modified construction - which does not use random oracles either - obtains a forward-secure signature with untrusted updates from any 2-party multi-signature in the plain public key model. In combination with Bellare and Neven's multi-signatures, our generic method yields implementations based on standard assumptions such as RSA, factoring or the hardness of computing discrete logarithms. Like the original MMM scheme, it does not require to set a bound on the number of time periods at key generation.

  • Forward-secure signatures in untrusted update environments
    Proceedings of the 14th ACM conference on Computer and communications security - CCS '07, 2007
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-secure signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer's storage. To simplify the integration of these primitives into standard security architectures, Boyen, Shacham, Shen and Waters recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages. The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. The latter work also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature and left open the problem of endowing other existing FSS systems with the same second factor protection. This paper solves this problem by showing how to adapt the very efficient generic construction of Malkin, Micciancio and Miner (MMM) to untrusted update environments. More precisely, our modified construction - which does not use random oracles either - obtains a forward-secure signature with untrusted updates from any 2-party multi-signature in the plain public key model. In combination with Bellare and Neven's multi-signatures, our generic method yields implementations based on standard assumptions such as RSA, factoring or the hardness of computing discrete logarithms. Like the original MMM scheme, it does not require to set a bound on the number of time periods at key generation.

Benoît Libert - One of the best experts on this subject based on the ideXlab platform.

  • Key Evolution Systems in Untrusted Update Environments
    ACM Transactions on Information and System Security, 2010
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-Secure Signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer’s storage by evolving the private key in a one-way fashion. To simplify the integration of these primitives into standard security architectures, Boyen et al. [2006] recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages and not at update time (since update is not user-driven). The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. They also suggest the integration of untrusted updates in the Bellare-Miner forward-secure signature. Their work left open the problem of endowing other existing FSS systems with the same second factor protection, and a natural second question is whether the method can apply to other key-evolving paradigms. This article solves the first problem by showing an efficient generic construction that does not require to set a bound on the number of time periods at key generation. The article then extends the unprotected update model to other key-evolving primitives such as forward-secure public key encryption and key-insulated cryptosystems.

  • Inscrypt - Key Evolution Systems in Untrusted Update Environments
    Information Security and Cryptology, 2009
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Key-evolving protocols aim at limiting damages when an attacker obtains full access to the signer's storage. To simplify the integration of such mechanisms into standard security architectures, Boyen, Shacham, Shen and Waters suggested the construction of forward-secure signatures (FSS) that protect past periods after a break-in, with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of private keys so that passwords only come into play for signing messages. Boyen et al. described a pairing-based scheme in the standard model and also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature. They left open the problem of endowing other efficient FSS systems with the same second factor protection. We first address this problem and suggest generic ways to construct FSS schemes in untrusted update environments. In a second step, we extend the unprotected update model to other key-evolving systems such as forward-secure public key encryption and key-insulated cryptosystems. We then explain how some of the constructions that we proposed for forward-secure signatures can be adapted to these models.

  • Key evolution systems in untrusted update environments
    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    {Forward-Secure} Signatures {(FSS)} prevent forgeries for past time\nperiods when an attacker obtains full access to the signer{\textquoteright}s\nstorage by evolving the private key in a one-way fashion. To simplify\nthe integration of these primitives into standard security architectures,\nBoyen et al. [2006] recently introduced the concept of forward-secure\nsignatures with untrusted updates where private keys are additionally\nprotected by a second factor (derived from a password). Key updates\ncan be made on Encrypted Version of signing keys so that passwords\nonly come into play for signing messages and not at update time (since\nupdate is not user-driven). The scheme put forth by Boyen et al.\nrelies on bilinear maps and does not require the random oracle. They\nalso suggest the integration of untrusted updates in the {Bellare-Miner}\nforward-secure signature. Their work left open the problem of endowing\nother existing {FSS} systems with the same second factor protection,\nand a natural second question is whether the method can apply to\nother key-evolving paradigms. This article solves the first problem\nby showing an efficient generic construction that does not require\nto set a bound on the number of time periods at key generation. The\narticle then extends the unprotected update model to other key-evolving\nprimitives such as forward-secure public key encryption and key-insulated\ncryptosystems.

  • ACM Conference on Computer and Communications Security - Forward-secure signatures in untrusted update environments: efficient and generic constructions
    Proceedings of the 14th ACM conference on Computer and communications security - CCS '07, 2007
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-secure signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer's storage. To simplify the integration of these primitives into standard security architectures, Boyen, Shacham, Shen and Waters recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages. The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. The latter work also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature and left open the problem of endowing other existing FSS systems with the same second factor protection. This paper solves this problem by showing how to adapt the very efficient generic construction of Malkin, Micciancio and Miner (MMM) to untrusted update environments. More precisely, our modified construction - which does not use random oracles either - obtains a forward-secure signature with untrusted updates from any 2-party multi-signature in the plain public key model. In combination with Bellare and Neven's multi-signatures, our generic method yields implementations based on standard assumptions such as RSA, factoring or the hardness of computing discrete logarithms. Like the original MMM scheme, it does not require to set a bound on the number of time periods at key generation.

  • Forward-secure signatures in untrusted update environments
    Proceedings of the 14th ACM conference on Computer and communications security - CCS '07, 2007
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-secure signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer's storage. To simplify the integration of these primitives into standard security architectures, Boyen, Shacham, Shen and Waters recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages. The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. The latter work also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature and left open the problem of endowing other existing FSS systems with the same second factor protection. This paper solves this problem by showing how to adapt the very efficient generic construction of Malkin, Micciancio and Miner (MMM) to untrusted update environments. More precisely, our modified construction - which does not use random oracles either - obtains a forward-secure signature with untrusted updates from any 2-party multi-signature in the plain public key model. In combination with Bellare and Neven's multi-signatures, our generic method yields implementations based on standard assumptions such as RSA, factoring or the hardness of computing discrete logarithms. Like the original MMM scheme, it does not require to set a bound on the number of time periods at key generation.

Kin Tak U. - One of the best experts on this subject based on the ideXlab platform.

  • CSE - A Novel Video Steganography Based on Non-uniform Rectangular Partition
    2011 14th IEEE International Conference on Computational Science and Engineering, 2011
    Co-Authors: Sheng Dun Hu, Kin Tak U.
    Abstract:

    This paper proposes a novel Video Steganography which can hide an uncompressed secret video stream in a host video stream with almost the same size. Each frame of the secret video will be Non-uniform rectangular partitioned and the partitioned codes obtained can be an Encrypted Version of the original frame. These codes will be hidden in the Least 4 Significant Bits of each frames of the host video. Experimental results showed that this algorithm can hide a same-size video in the host video without obvious distortion in the host video.

  • A Novel Video Steganography Based on Non-uniform Rectangular Partition
    2011 14th IEEE International Conference on Computational Science and Engineering, 2011
    Co-Authors: Sheng Dun Hu, Kin Tak U.
    Abstract:

    This paper proposes a novel Video Steganography which can hide an uncompressed secret video stream in a host video stream with almost the same size. Each frame of the secret video will be Non-uniform rectangular partitioned and the partitioned codes obtained can be an Encrypted Version of the original frame. These codes will be hidden in the Least 4 Significant Bits of each frames of the host video. Experimental results showed that this algorithm can hide a same-size video in the host video without obvious distortion in the host video.

Jean-jacques Quisquater - One of the best experts on this subject based on the ideXlab platform.

  • Key Evolution Systems in Untrusted Update Environments
    ACM Transactions on Information and System Security, 2010
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-Secure Signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer’s storage by evolving the private key in a one-way fashion. To simplify the integration of these primitives into standard security architectures, Boyen et al. [2006] recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages and not at update time (since update is not user-driven). The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. They also suggest the integration of untrusted updates in the Bellare-Miner forward-secure signature. Their work left open the problem of endowing other existing FSS systems with the same second factor protection, and a natural second question is whether the method can apply to other key-evolving paradigms. This article solves the first problem by showing an efficient generic construction that does not require to set a bound on the number of time periods at key generation. The article then extends the unprotected update model to other key-evolving primitives such as forward-secure public key encryption and key-insulated cryptosystems.

  • Inscrypt - Key Evolution Systems in Untrusted Update Environments
    Information Security and Cryptology, 2009
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Key-evolving protocols aim at limiting damages when an attacker obtains full access to the signer's storage. To simplify the integration of such mechanisms into standard security architectures, Boyen, Shacham, Shen and Waters suggested the construction of forward-secure signatures (FSS) that protect past periods after a break-in, with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of private keys so that passwords only come into play for signing messages. Boyen et al. described a pairing-based scheme in the standard model and also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature. They left open the problem of endowing other efficient FSS systems with the same second factor protection. We first address this problem and suggest generic ways to construct FSS schemes in untrusted update environments. In a second step, we extend the unprotected update model to other key-evolving systems such as forward-secure public key encryption and key-insulated cryptosystems. We then explain how some of the constructions that we proposed for forward-secure signatures can be adapted to these models.

  • Key evolution systems in untrusted update environments
    Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    {Forward-Secure} Signatures {(FSS)} prevent forgeries for past time\nperiods when an attacker obtains full access to the signer{\textquoteright}s\nstorage by evolving the private key in a one-way fashion. To simplify\nthe integration of these primitives into standard security architectures,\nBoyen et al. [2006] recently introduced the concept of forward-secure\nsignatures with untrusted updates where private keys are additionally\nprotected by a second factor (derived from a password). Key updates\ncan be made on Encrypted Version of signing keys so that passwords\nonly come into play for signing messages and not at update time (since\nupdate is not user-driven). The scheme put forth by Boyen et al.\nrelies on bilinear maps and does not require the random oracle. They\nalso suggest the integration of untrusted updates in the {Bellare-Miner}\nforward-secure signature. Their work left open the problem of endowing\nother existing {FSS} systems with the same second factor protection,\nand a natural second question is whether the method can apply to\nother key-evolving paradigms. This article solves the first problem\nby showing an efficient generic construction that does not require\nto set a bound on the number of time periods at key generation. The\narticle then extends the unprotected update model to other key-evolving\nprimitives such as forward-secure public key encryption and key-insulated\ncryptosystems.

  • ACM Conference on Computer and Communications Security - Forward-secure signatures in untrusted update environments: efficient and generic constructions
    Proceedings of the 14th ACM conference on Computer and communications security - CCS '07, 2007
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-secure signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer's storage. To simplify the integration of these primitives into standard security architectures, Boyen, Shacham, Shen and Waters recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages. The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. The latter work also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature and left open the problem of endowing other existing FSS systems with the same second factor protection. This paper solves this problem by showing how to adapt the very efficient generic construction of Malkin, Micciancio and Miner (MMM) to untrusted update environments. More precisely, our modified construction - which does not use random oracles either - obtains a forward-secure signature with untrusted updates from any 2-party multi-signature in the plain public key model. In combination with Bellare and Neven's multi-signatures, our generic method yields implementations based on standard assumptions such as RSA, factoring or the hardness of computing discrete logarithms. Like the original MMM scheme, it does not require to set a bound on the number of time periods at key generation.

  • Forward-secure signatures in untrusted update environments
    Proceedings of the 14th ACM conference on Computer and communications security - CCS '07, 2007
    Co-Authors: Benoît Libert, Jean-jacques Quisquater, Moti Yung
    Abstract:

    Forward-secure signatures (FSS) prevent forgeries for past time periods when an attacker obtains full access to the signer's storage. To simplify the integration of these primitives into standard security architectures, Boyen, Shacham, Shen and Waters recently introduced the concept of forward-secure signatures with untrusted updates where private keys are additionally protected by a second factor (derived from a password). Key updates can be made on Encrypted Version of signing keys so that passwords only come into play for signing messages. The scheme put forth by Boyen et al. relies on bilinear maps and does not require the random oracle. The latter work also suggested the integration of untrusted updates in the Bellare-Miner forward-secure signature and left open the problem of endowing other existing FSS systems with the same second factor protection. This paper solves this problem by showing how to adapt the very efficient generic construction of Malkin, Micciancio and Miner (MMM) to untrusted update environments. More precisely, our modified construction - which does not use random oracles either - obtains a forward-secure signature with untrusted updates from any 2-party multi-signature in the plain public key model. In combination with Bellare and Neven's multi-signatures, our generic method yields implementations based on standard assumptions such as RSA, factoring or the hardness of computing discrete logarithms. Like the original MMM scheme, it does not require to set a bound on the number of time periods at key generation.

Rangding Wang - One of the best experts on this subject based on the ideXlab platform.

  • Context adaptive binary arithmetic coding-based data hiding in partially Encrypted H.264/AVC videos
    Journal of Electronic Imaging, 2015
    Co-Authors: Dawen Xu, Rangding Wang
    Abstract:

    A scheme of data hiding directly in a partially Encrypted Version of H.264/AVC videos is proposed which includes three parts, i.e., selective encryption, data embedding and data extraction. Selective encryption is performed on context adaptive binary arithmetic coding (CABAC) bin-strings via stream ciphers. By careful selection of CABAC entropy coder syntax elements for selective encryption, the Encrypted bitstream is format-compliant and has exactly the same bit rate. Then a data-hider embeds the additional data into partially Encrypted H.264/AVC videos using a CABAC bin-string substitution technique without accessing the plaintext of the video content. Since bin-string substitution is carried out on those residual coefficients with approximately the same magnitude, the quality of the decrypted video is satisfactory. Video file size is strictly preserved even after data embedding. In order to adapt to different application scenarios, data extraction can be done either in the Encrypted domain or in the decrypted domain. Experimental results have demonstrated the feasibility and efficiency of the proposed scheme.

  • Data Hiding in Encrypted H.264/AVC Video Streams by Codeword Substitution
    IEEE Transactions on Information Forensics and Security, 2014
    Co-Authors: Dawen Xu, Rangding Wang
    Abstract:

    Digital video sometimes needs to be stored and processed in an Encrypted format to maintain security and privacy. For the purpose of content notation and/or tampering detection, it is necessary to perform data hiding in these Encrypted videos. In this way, data hiding in Encrypted domain without decryption preserves the confidentiality of the content. In addition, it is more efficient without decryption followed by data hiding and re-encryption. In this paper, a novel scheme of data hiding directly in the Encrypted Version of H.264/AVC video stream is proposed, which includes the following three parts, i.e., H.264/AVC video encryption, data embedding, and data extraction. By analyzing the property of H.264/AVC codec, the codewords of intraprediction modes, the codewords of motion vector differences, and the codewords of residual coefficients are Encrypted with stream ciphers. Then, a data hider may embed additional data in the Encrypted domain by using codeword substitution technique, without knowing the original video content. In order to adapt to different application scenarios, data extraction can be done either in the Encrypted domain or in the decrypted domain. Furthermore, video file size is strictly preserved even after encryption and data embedding. Experimental results have demonstrated the feasibility and efficiency of the proposed scheme.