The Experts below are selected from a list of 4245 Experts worldwide ranked by ideXlab platform
Michel Kieffer - One of the best experts on this subject based on the ideXlab platform.
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Robust IP and UDP-lite header recovery for packetized multimedia transmission
2010Co-Authors: Michel Kieffer, François MériauxAbstract:Recently, Joint Source-Channel Decoding (JSCD) techniques have been proposed to improve the reception of multimedia contents transmitted over error-prone channels. These techniques take advantage of the redundancy left by the source coder and of bit reliability measures (soft information) provided by channel decoders to correct transmission errors. To be put at work, Protocol stacks have to be made permeable to transmission errors in order to allow soft information to reach the upper Protocol Layers. For that purpose, headers have to be reliably estimated at each Protocol Layer. First results have been obtained for lower Protocol Layers (PHY and MAC) protected by CRCs. The aim of this paper is to extend these results to upper Protocol Layers (IP and UDP-lite) protected by checksums. As for CRCs, trellis-based decoding techniques may be employed for data protected by checksums. Nevertheless, specific tools have been proposed in this paper to reach a complexity-efficiency trade-off.
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ICASSP - Robust IP and UDP-lite header recovery for packetized multimedia transmission
2010 IEEE International Conference on Acoustics Speech and Signal Processing, 2010Co-Authors: François Mériaux, Michel KiefferAbstract:Recently, Joint Source-Channel Decoding (JSCD) techniques have been proposed to improve the reception of multimedia contents transmitted over error-prone channels. These techniques take advantage of the redundancy left by the source coder and of bit reliability measures (soft information) provided by channel decoders to correct transmission errors. To be put at work, Protocol stacks have to be made permeable to transmission errors in order to allow soft information to reach the upper Protocol Layers. For that purpose, headers have to be reliably estimated at each Protocol Layer. First results have been obtained for lower Protocol Layers (PHY and MAC) protected by CRCs. The aim of this paper is to extend these results to upper Protocol Layers (IP and UDP-lite) protected by checksums. As for CRCs, trellis-based decoding techniques may be employed for data protected by checksums. Nevertheless, specific tools have been proposed in this paper to reach a complexity-efficiency trade-off1.
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Robust MAC-Lite and Header Recovery Based Improved Permeable Protocol Layer Scheme
2008 IEEE 10th International Symposium on Spread Spectrum Techniques and Applications, 2008Co-Authors: Cedric Marin, Yann Leprovost, Michel Kieffer, Pierre DuhamelAbstract:This paper presents an improved permeable Layer mechanism useful for highly robust packetized multimedia trans- mission. MAP estimation-based packet header recovery at vari- ous Protocol Layers is the cornerstone of the proposed solution. This header-correction technique exploits the available intra- Layer and inter-Layer header correlation to define a reduced set of header configurations. The best candidate is then selected in the pre-defined set through a soft decoding based on CRC redundancy. To improve the decoding performance, we also generalize the principle of UDP-Lite and propose a robust MAC Layer, called MAC-Lite. Simulation results for WiFi transmission over AWGN channels assess a substantial (12 dB) link budget improvement. multimedia data for reconstructing some information in place of the missing one. In the recent past, joint source-channel decoding methods have been proposed to efficiently recover corrupted packets. These techniques involve robust source decoders and exploit the residual redundancy in the received packets for correcting errors (5)-(10). These robust decoders improve the link budget of the multimedia transmission when compared to classical schemes. These robust solutions are however not compliant with the standard Protocol stacks since they require exchange of soft information from the Physical (PHY) Layer to the APL Layer. Nevertheless, the error-detection mechanisms included in the standard Protocol stacks prevent corrupted packets to reach the APL Layer. The main reason being that the errors may impact some essential information contained in the various headers at intermediate Protocol Layers. To circumvent the above inconsistency, we first propose a robust Protocol Layer scheme where error-detection codes are applied to the header fields only. Then, we introduce an efficient header recovery technique for correcting the corrupted headers. More headers are thus correctly interpreted at each Layer, increasing the number of packets reaching the APL Layer. This combination allows to obtain an improved per- meable (11) Protocol Layer mechanism having the ability of exchanging soft information between Protocol Layers. The paper is organized as follows. After an introduction of the improved permeable Layer scheme in Section II, Section III describes the derivation of the header recovery technique. The design of the proposed mechanism for PHY and MAC Layers of WiFi is then detailed in Section IV. Finally, simulation results are presented in Section V before drawing some conclusions.
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Robust header recovery based enhanced permeable Protocol Layer mechanism
2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications, 2008Co-Authors: Cedric Marin, Yann Leprovost, Michel Kieffer, Pierre DuhamelAbstract:This paper presents an enhanced permeable Layer mechanism useful for reliable packetized multimedia transmission. Packet header recovery at various Protocol Layers using MAP estimation is the cornerstone of the proposed solution. The available intra-Layer and inter-Layer header correlation is used to define a reduced set of header configurations for further processing. The best candidate is then obtained through soft decoding based on CRC redundancy. Simulation results for a WiFi transmission scheme using DBPSK modulated signals over an AWGN channel show a substantial (4 to 12 dB) link budget improvement. A sub-optimal and hardware realizable version of the proposed algorithm is also presented.
Eduardo B Fernandez - One of the best experts on this subject based on the ideXlab platform.
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cipher suite rollback a misuse pattern for the ssl tls client server authentication handshake Protocol
PLoP '14 Proceedings of the 21st Conference on Pattern Languages of Programs, 2014Co-Authors: Ali Alkazimi, Eduardo B FernandezAbstract:Transport Layer Security (TLS) is a cryptographic Protocol that provides a secure channel between a client and a server. TLS is the successor to the Secure Sockets Layer (SSL) Protocol. The secure connection prevents an attacker from eavesdropping an established client-server connection. It is used in most internet communications for enabling secure web browsing. The SSL/TLS security Protocol is Layered between the application Protocol Layer and the TCP/IP Layer and includes as one of its sub-Protocols the Handshake Protocol. We present here a misuse pattern for the SSL/TLS Handshake Protocol: the Cipher Suite Rollback, where the attacker intercepts the "ClientHello" message, replaces the CipherSuite (a list of encryption algorithms), with a weak or NULL-Cipher, and passes the intercepted message to the server which will now use a weaker cipher, allowing the attacker to gain access to the exchanged data between the client and the server.
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Cipher suite rollback: a misuse pattern for the SSL/TLS client/server authentication handshake Protocol
2014Co-Authors: Ali Alkazimi, Eduardo B FernandezAbstract:Transport Layer Security (TLS) is a cryptographic Protocol that provides a secure channel between a client and a server. TLS is the successor to the Secure Sockets Layer (SSL) Protocol. The secure connection prevents an attacker from eavesdropping an established client-server connection. It is used in most internet communications for enabling secure web browsing. The SSL/TLS security Protocol is Layered between the application Protocol Layer and the TCP/IP Layer and includes as one of its sub-Protocols the Handshake Protocol. We present here a misuse pattern for the SSL/TLS Handshake Protocol: the Cipher Suite Rollback, where the attacker intercepts the "ClientHello" message, replaces the CipherSuite (a list of encryption algorithms), with a weak or NULL-Cipher, and passes the intercepted message to the server which will now use a weaker cipher, allowing the attacker to gain access to the exchanged data between the client and the server.
François Mériaux - One of the best experts on this subject based on the ideXlab platform.
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Robust IP and UDP-lite header recovery for packetized multimedia transmission
2010Co-Authors: Michel Kieffer, François MériauxAbstract:Recently, Joint Source-Channel Decoding (JSCD) techniques have been proposed to improve the reception of multimedia contents transmitted over error-prone channels. These techniques take advantage of the redundancy left by the source coder and of bit reliability measures (soft information) provided by channel decoders to correct transmission errors. To be put at work, Protocol stacks have to be made permeable to transmission errors in order to allow soft information to reach the upper Protocol Layers. For that purpose, headers have to be reliably estimated at each Protocol Layer. First results have been obtained for lower Protocol Layers (PHY and MAC) protected by CRCs. The aim of this paper is to extend these results to upper Protocol Layers (IP and UDP-lite) protected by checksums. As for CRCs, trellis-based decoding techniques may be employed for data protected by checksums. Nevertheless, specific tools have been proposed in this paper to reach a complexity-efficiency trade-off.
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ICASSP - Robust IP and UDP-lite header recovery for packetized multimedia transmission
2010 IEEE International Conference on Acoustics Speech and Signal Processing, 2010Co-Authors: François Mériaux, Michel KiefferAbstract:Recently, Joint Source-Channel Decoding (JSCD) techniques have been proposed to improve the reception of multimedia contents transmitted over error-prone channels. These techniques take advantage of the redundancy left by the source coder and of bit reliability measures (soft information) provided by channel decoders to correct transmission errors. To be put at work, Protocol stacks have to be made permeable to transmission errors in order to allow soft information to reach the upper Protocol Layers. For that purpose, headers have to be reliably estimated at each Protocol Layer. First results have been obtained for lower Protocol Layers (PHY and MAC) protected by CRCs. The aim of this paper is to extend these results to upper Protocol Layers (IP and UDP-lite) protected by checksums. As for CRCs, trellis-based decoding techniques may be employed for data protected by checksums. Nevertheless, specific tools have been proposed in this paper to reach a complexity-efficiency trade-off1.
Ali Alkazimi - One of the best experts on this subject based on the ideXlab platform.
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cipher suite rollback a misuse pattern for the ssl tls client server authentication handshake Protocol
PLoP '14 Proceedings of the 21st Conference on Pattern Languages of Programs, 2014Co-Authors: Ali Alkazimi, Eduardo B FernandezAbstract:Transport Layer Security (TLS) is a cryptographic Protocol that provides a secure channel between a client and a server. TLS is the successor to the Secure Sockets Layer (SSL) Protocol. The secure connection prevents an attacker from eavesdropping an established client-server connection. It is used in most internet communications for enabling secure web browsing. The SSL/TLS security Protocol is Layered between the application Protocol Layer and the TCP/IP Layer and includes as one of its sub-Protocols the Handshake Protocol. We present here a misuse pattern for the SSL/TLS Handshake Protocol: the Cipher Suite Rollback, where the attacker intercepts the "ClientHello" message, replaces the CipherSuite (a list of encryption algorithms), with a weak or NULL-Cipher, and passes the intercepted message to the server which will now use a weaker cipher, allowing the attacker to gain access to the exchanged data between the client and the server.
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Cipher suite rollback: a misuse pattern for the SSL/TLS client/server authentication handshake Protocol
2014Co-Authors: Ali Alkazimi, Eduardo B FernandezAbstract:Transport Layer Security (TLS) is a cryptographic Protocol that provides a secure channel between a client and a server. TLS is the successor to the Secure Sockets Layer (SSL) Protocol. The secure connection prevents an attacker from eavesdropping an established client-server connection. It is used in most internet communications for enabling secure web browsing. The SSL/TLS security Protocol is Layered between the application Protocol Layer and the TCP/IP Layer and includes as one of its sub-Protocols the Handshake Protocol. We present here a misuse pattern for the SSL/TLS Handshake Protocol: the Cipher Suite Rollback, where the attacker intercepts the "ClientHello" message, replaces the CipherSuite (a list of encryption algorithms), with a weak or NULL-Cipher, and passes the intercepted message to the server which will now use a weaker cipher, allowing the attacker to gain access to the exchanged data between the client and the server.
Satish K. Tripathi - One of the best experts on this subject based on the ideXlab platform.
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Studying vertical dependence to improve NFS performance in wireless networks
Cluster Computing, 1998Co-Authors: Cynthia D. Rais, Satish K. TripathiAbstract:Wireless networks experience a high level of errors and losses. These physical Layer characteristics have an impact on the performance of the higher Layers. In addition, the performance of each Protocol Layer is contingent on the behavior of the other Layers. Vertical dependency is a term which describes this inter-dependence between Layers. In the wireless and mobile environment, the effects of vertical dependence are particularly pronounced due to the dynamic nature of the environment and due to the fact that traditional assumptions about Protocol Layer interactions do not always hold. In this paper, we consider the vertical dependencies between various Layers in the Protocol stack, studying the performance of the Network File System under various error models and improvement techniques. Our experimental results demonstrate the dependency of the application performance on the details of the error characteristics and other Protocol Layers. After studying the vertical dependencies, we improve NFS performance by implementing changes to the application level reliability mechanisms. Understanding of the vertical dependencies enables development of effective methods for performance enhancement and efficient reaction to errors and changes on the wireless media.
