Tobias Lauinger

Investigates the effectiveness of current and proposed anti-"piracy" measures in the One-Click Hosting (OCH) ecosystem. Shows that despite takedown efforts targeting files or even entire hosting services such as Megaupload, infringing content remains available for rather long time periods. Measures included in the SOPA law proposal, for instance, can either be circumvented by users, or they target the "wrong" actors of the ecosystem. However, there is first evidence that some measures force hosting services to increase their own anti-abuse efforts. While this may lead to reduced availability of infringing content, it is unlikely that these developments will solve the issue of copyright infringement on the Internet.

Talk outlining the cache privacy attack in Content-Centric Networking and the main arguments for countermeasures from the editorial note.

Discusses at a high level several solution approaches to defend against the cache privacy attack in Content-Centric Networking (CCN), which is described in the technical report and the Master's thesis. Advocates the timely implementation of countermeasures so that users are not exposed to privacy risks, and that privacy-conscious users don't resort to generalised tunnelling of their traffic as a countermeasure. The latter would disable caching in the access network and could lead to degraded overall network performance.

Provides attack algorithms that exploit ubiquitous network-level caches in the Content-Centric Networking (CCN) architecture to compromise the privacy of users without requiring any special privileges for the attacker. The algorithms are given for a variety of assumptions regarding protocol features (such as the presence of a hop count field) and replacement policies. The attack allows arbitrary users of a cache to collect information about the network traffic of their neighbours. Extended and updated version of the cache privacy attack first described in the Master's thesis.

Many One-Click Hosters (OCHs) used to operate affiliate programmes that financially rewarded uploaders of popular files. These programmes were controversial for allegedly encouraging copyright infringement. We anaysed publicly observable pay-per-download income on three web sites where uploaders could publish their download links. The inferred income could be quite high in a few cases, but most uploaders earned next to nothing. Since users uploaded a lot of unpopular content and most content was also uploaded by users with low income, we conclude that the affiliate programmes don't appear to be a major driver for copyright infringement, at least on the three observed sites.

Content-Centric Networking (CCN) is a proposal for a new Internet architecture based on content names instead of location identifiers as it is the case today. While CCN claims to solve several security issues in the current Internet, it also introduces a potential for new attacks. This thesis gives an overview of several denial-of-service and privacy attacks against CCN. It then analyses in detail an attack that compromises the privacy of users by exploiting information stored in network-level caches. The thesis led to the publication of a more detailed technical report and a more general editorial note covering this attack.

Experiment carried out in IRC channels to measure how users react to different kinds of chat spam, and how conversations can be influenced in an automated way. Set up conversations by contacting two users with private messages and relaying these messages between the users in a man-in-the-middle fashion. Showed that this technique can result in surprisingly high click rates. Such attacks are difficult to detect and give the attacker full control over the conversation. Countermeasures are challenging in settings such as online chat when there is no previously established trust relationship between two users.

Introduces a way of optimising overlay routing in the Kademlia Distributed Hash Table (DHT) according to a distance metric in the underlay network (such as point-to-point latencies in the Internet). Can significantly reduce the delay of searches in the DHT, provided that the typical network transmission delays between peers are larger than non-optimisable delay components such as queueing delays in home modems (that is, modem buffers should be small, or empty). Analogous to "peer locality" efforts aiming to transfer large content objects preferably between nearby peers, but operating at the DHT level. Could be useful in a context where near real-time searches are necessary.

Proposes to optimise overlay routing in the Kademlia Distributed Hash Table (DHT) by organising peers in clusters of a "virtual hierarchy" and by selecting paths from within a peer's own cluster for as long as possible. In contrast to prior work, designed to work with iterative routing algorithms (such as in Kademlia), and with less strict requirements than in a real hierarchical DHT. As follow-up work with the tutor of my thesis, the routing algorithms were abstracted to function with arbitrary underlay metrics, and the results were published as a paper at P2P'08.