Matthäus Wander

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The housing of personal data on large online social networks arouses concerns from privacy advocates and leery users. Researchers have proposed decentralized architectures to create online social networks with technically imposed privacy preservation. This survey of several approaches discusses their privacy benefits, architecture, and suitability for(More)
In this paper we propose a federated online social network (OSN) which focuses on user privacy and data availability. All user content is encrypted and decrypted on end-user devices, hiding the content from the OSN providers. The social graph is hidden from the OSN provider by employing a novel aliasing approach and using secure algorithms for mutual(More)
When a client queries for a non-existent name in the Domain Name System (DNS), the server responds with a negative answer. With the DNS Security Extensions (DNSSEC), the server can either use NSEC or NSEC3 for authenticated negative answers. NSEC3 claims to protect DNSSEC servers against domain enumeration, but incurs significant CPU and bandwidth overhead.(More)
This article presents an architecture for research and development of peer-to-peer (P2P) systems. A complete P2P application has to cope with problems such as NAT-traversal, bootstrapping, connection management, routing, storage, and security. Therefore, our approach separates the system into layers and components. A developer can easily build a complete(More)
The shortage of IPv4 addresses and the very slow transition to IPv6 leads to well-established pragmatic solutions in the Internet: today many hosts are still using IPv4 and are connected to the Internet over a Network Address Translation router. For many applications, which need inbound connections, like e.g. voice-over-IP or peer-to-peer-based systems it(More)
Modern cryptanalytic algorithms require a large amount of computational power. An approach to cope with this requirement is to distribute these algorithms among many computers and to perform the computation massively parallel. However, existing approaches for distributing cryptanalytic algorithms are based on a client/server or a grid architecture. In this(More)
The shortage of IPv4 addresses and the very slow transition to IPv6 leads to pragmatic solutions in the Internet: today many hosts are still using IPv4 and are connected to the Internet over a Network Address Translation (NAT) router. However, there are many applications, which need inbound connections, like e.g. peer-to-peer-based systems or voice-over-IP.(More)