SSS'10 Proceedings of the 12th international conference on Stabilization, safety, and security of distributed systems
Virtual private social networks
Proceedings of the first ACM conference on Data and application security and privacy
Measuring profile distance in online social networks
Proceedings of the International Conference on Web Intelligence, Mining and Semantics
Towards attack resilient social network based threshold signing
Inscrypt'11 Proceedings of the 7th international conference on Information Security and Cryptology
Virtual private social networks and a facebook implementation
ACM Transactions on the Web (TWEB)
Information and Computation
| Hi-index | 0.00 |
We study a new application of threshold-based secret sharing in a distributed online social network (DOSN), where users need a means to back up and recover their private keys in a network of untrusted servers. Using a simple threshold-based secret sharing in such an environment is insufficiently secured since delegates keeping the secret shares may collude to steal the user's private keys. To mitigate this problem, we propose using different techniques to improve the system security: by selecting only the most reliable delegates for keeping these shares and further by encrypting the shares with passwords. We develop a mechanism to select the most reliable delegates based on an effective trust measure. Specifically, relationships among the secret owner, delegate candidates and their related friends are used to estimate the trustworthiness of a delegate. This trust measure minimizes the likelihood of the secret being stolen by an adversary and is shown to be effective against various collusive attacks. Extensive simulations show that the proposed trust-based delegate selection performs very well in highly vulnerable environments where the adversary controls many nodes with different distributions and even with spreading of infections in the network. In fact, the number of keys lost is very low under extremely pessimistic assumptions of the adversary model.