Abstract: Disclosed is a system and method for encryption of a scalable video coding (SVC) bitstream, which is the next-generation coding technology. The encryption method encrypts Network Abstraction Layer (NAL) data identified according to multidimensional scalability for space, time, and quality with respect to a bitstream created after an SVC encoding, thereby providing a multidimensional scalability function for space, time, and quality even after the encryption, so that the scalability is also maintained even in a bitstream extraction process after the encryption. According to such a scalable encryption method, a specific portion of an encrypted bitstream is removed in a bitstream extraction process, and user access to the bitstream is limited based on a combination of keys for accessing a specific scalability. Therefore, it is possible to protect scalable video content and to access the video content based on scalabilities.

Abstract: The invention relates to a system and method that can detect botnets by classifying the communication activities for each client according to destination or based on similarity between the groups of collected traffic. According to certain aspects of the invention, the communication activities for each client can be classified to model network activity by differentiating the protocols of the collected network traffic based on destination and patterning the subgroups for the respective protocols. Those servers that are estimated to be C&C servers can be classified into download and upload, spam servers and command control servers, within a botnet group detected by modeling network activity, i.e. analyzing network-based activity patterns. Also, botnet groups can be detected by way of a group information management function, for generating an activity pattern-based group matrix based on group data, and a mutual similarity analysis, performed on groups suspected to be botnets from the group information.

Abstract: The present invention relates to a malicious traffic isolation system and method using botnet information, and more particularly, to a malicious traffic isolation system and method using botnet information, in which traffics for a set of clients having the same destination are routed to the isolation system based on a destination IP/Port, and botnet traffics are isolated using botnet information based on similarity among groups of the routed and flowed in traffics. The present invention may provide a malicious traffic isolation method using botnet information, which can accommodate traffics received from a PC or a C&C server infected with a bot into a quarantine area, isolate traffics generated by normal users from traffics transmitted from malicious bots, and block the malicious traffics. In addition, the present invention may provide a malicious traffic isolation method using botnet information, which can provide a function of mitigating DDoS attacks of a botnet.

Abstract: Disclosed is a system for lawful interception using a trusted third party in secure VoIP communication. A VoIP transmit terminal generates a secure packet using a master key received from a trusted third party and then communicates with a VoIP receive terminal. A collection device having received a lawful interception instruction from a key recovering system collects and transmits the secure packet to the key recovering system. The key recovering system decrypts the secure packet using the master key received from the trusted third party and provides the decrypted secure packet to a lawful interception requester or provides the master key received from the trusted third party and the secure packet to the lawful interception requester. It is possible to provide the perfect lawful interception in the secure VoIP communication environment, and to guarantee a perfect forward secrecy since the master key is changed for each call.

Abstract: Disclosed is a security system of a call signaling message. An object of the invention is to provide a security system and a securing method of a call signaling message, in which even when a call signaling message is leaked out and thus modified in a SIP (Session Initiation Protocol) based VoIP (Voice Over Internet Protocol) service, the modified message is blocked in advance to enable the VoIP service to be provided without an attack effect by the packets. When using the security system and the securing method of a call signaling message according to an embodiment of the invention, it is possible to prevent, in the SIP based VoIP service, a call signaling message from being modified to cause a call failure when requesting a call or during the call, and to block an attack on the call signaling message in advance.

Abstract: Disclosed are a user agent providing secure VoIP communication and a secure communication method using the same. A user agent of the invention has an additional module for providing a secure function as well as a module for providing general communication, thereby supporting the secure communication. In addition, as a secure communication method using the user agent, a signaling security mechanism negotiation method and a media encryption algorithm negotiation method are provided. Hence, it is possible to provide internet telephone users with a secure VoIP communication service.

Abstract: Disclosed is a device for dropping an attack multimedia packet. An object of the invention is to provide a device, a system and a method for dropping an attack multimedia packet, capable of filtering RTP packets received to selectively drop an attack multimedia packet, thereby providing a stable multimedia service. According to the invention, the received RTP packet is filtered to selectively drop an attack multimedia packet, so that it is possible to provide a stable multimedia service.

Abstract: Disclosed is a system and method for encryption of a scalable video coding (SVC) bitstream, which is the next-generation coding technology. The encryption method encrypts Nation Adaptation Layer (NAL) data identified according to multidimensional scalability for space, time, and quality with respect to a bitstream created after an SVC encoding, thereby providing a multidimensional scalability function for space, time, and quality even after the encryption, so that the scalability is also maintained even in a bitstream extraction process after the encryption. According to such a scalable encryption method, a specific portion of an encrypted bitstream is removed in a bitstream extraction process, and user access to the bitstream is limited based on a combination of keys for accessing a specific scalability. Therefore, it is possible to protect scalable video content and to access the video content based on scalabilities.