Decentralized Online Social Networks

Current Online social networks (OSN) are web services run on logically centralized infrastructure. Large OSN sites use content distribution networks and thus distribute some of the load by caching for performance reasons, nevertheless there is a central repository for user and application data. This centralized nature of OSNs has several drawbacks including scalability, but more relevantly for our work, privacy, dependence on a provider (lack of user autonomy), need for being online for every transaction, and a lack of locality. There have thus been several efforts toward decentralizing OSNs while retaining the functionalities offered by centralized OSNs. A decentralized online social network (DOSN) is a distributed system for social networking with no or limited dependency on any dedicated central infrastructure, and uses end-user resources in a peer-to-peer manner to carry out the various functions instead. Below we provide further information on the various aspects of DOSNs that we work on.

For a more comprehensive survey (which is rapidly getting outdated) of related works, please refer to:
Decentralized Online Social Networks,
Anwitaman Datta, Sonja Buchegger, Le-Hung Vu, Thorsten Strufe, Krzysztof Rzadca
In Handbook of Social Network Technologies and Applications, Springer, 2010/11.

Systems, architecture, general overview

We were one of the earliest proponents of DOSNs, and laid out our early thoughts in the following paper.
A Case for P2P Infrastructure for Social Networks - Opportunities and Challenges
Sonja Buchegger, Anwitaman Datta.
In Proceedings of WONS 2009, The Sixth International Conference on Wireless On-demand Network Systems and Services, 2009.

Some of our experiences with a first attempt to implement a DOSN resulted in PeerSoN.
PeerSoN: P2P Social Networking - Early Experiences and Insights
Sonja Buchegger, Doris Schiöberg, Le Hung Vu, Anwitaman Datta.
In Proceedings of SocialNets 2009, The 2nd Workshop on Social Network Systems, 2009.

Based on the early experiences, we are now pursuing a new, super-peer based architecture. Early simulation based explorations on the desirability of such an architecture is described in the following manuscript.
SuperNova: Super-peers Based Architecture for Decentralized Online Social Networks
Rajesh Sharma, Anwitaman Datta.
Available on arXiv, 2011.

Storage issues

Replica Placement in P2P Storage: Complexity and Game Theoretic Analyses
Krzysztof Rzadca, Anwitaman Datta, Sonja Buchegger
In Proceedings of ICDCS 2010.

An empirical study of availability in friend-to-friend storage systems
Rajesh Sharma, Anwitaman Datta, Matteo del Amico, Pietro Michiardi
In Proceedings of P2P 2011.

More information about our work on general issues of peer-to-peer storage systems.

Security, access control, privacy

Enabling Secure Secret Sharing in Distributed Online Social Networks
Le Hung Vu, Karl Aberer, Sonja Buchegger, Anwitaman Datta
In Proceedings of Annual Computer Security Applications Conference (ACSAC) 2009.

Anonymous gossiping
Anwitaman Datta
Arxiv manuscript (June 2010).

Information dissemination

GoDisco: Selective Gossip based Dissemination of Information in Social Community based Overlays
Anwitaman Datta, Rajesh Sharma
International conference on distributed computing and networking (ICDCN) 2011.

Trust, reputation, incentives

Ongoing work. More later.

Data management

Mapping Social Networks into P2P Directory Service,
Lukasz Zaczek, Anwitaman Datta
SocInfo 2009, International Conference on Social Informatics

GutenTag: A Multi-Term Caching Optimized Tag Query Processor for Key-Value Based NoSQL Storage Systems,
Christian von der Weth, Anwitaman Datta
Available on arXiv, May 2011

Niche applications

Besides investigating various aspects of DOSNs, and our efforts on building a general purpose DOSN, we are also looking at some niche social/collaboration networks applications. Specifically, we are developing (i) techniques to enhance and facilitate collaborative web search (COBS) and (ii) a social library for collaborative knowledge sharing (SoJa).

COBS: A Tool For Collaborative Browsing And Search On The Web
Christian von der Weth, Sally Ang, Anwitaman Datta
IEEE International Conference on Multimedia & Expo (ICME 2010)

SoJa: Collaborative Reference Management Using A Decentralized Social Information System
Anwitaman Datta
International Conference on Collaborative Computing: Networking, Applications and Worksharing (CollaborateCom 2010) Invited paper

* The current implementation of COBS and SoJa use a hybrid architecture.