The topmost concern of users who are kept under surveillance by a CCTV-System is the loss of their privacy. To gain a high acceptance by the monitored users, we have to assure, that the recorded video-material is only available to a subset of authorized users under exactly previously defined circumstances. In this paper we propose a CCTV video surveillance system providing privacy in a distributed way using threshold multi-party computation. Due to the flexibility of the access structure, we can handle the problem of loosing private-key-shares that are necessary for reconstructing video-material as well as adding new users to the system. If a pre-defined threshold is reached, a shared update of the master secret and the according re-encryption of previously stored ciphertext without revealing the plaintext is provided.
This paper describes the design and implementation of a secure internet phone utilizing a smartcard-based public key infrastructure. First, available hardware and software based systems are discussed followed by a description of the architecture of our system. More detailed information on the public key infrastructure including the certification authority, the client and the public key server are to come in chapters thereafter. The article finishes with a concise description of the audio subsystem.
1.The curriculum of the studies in "Angewandte Informatik" (Applied Computer Science) requires a small project to be carried out in order to gain hands-on experience ofhow software development works. As in real life and in order to experience a true project feeling, the project should be done by at least two people. Because we started specializing in security, we decided to carry out our project in this field. We found the first lack of security in Internet communication systems while we were playing games that use voice communication over networks. After analysing several other communication systems, the idea of the "Secure Internet Phone" (SIP) was born. The aims our SIP-design set out to achieve were as follows: • authenticity of the involved users (calling and receiving party),• confidentiality and integrity of the call data and protocol data,
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.