Enabling Secure Secret Sharing in Distributed Online Social Networks

Abstract

Abstract-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 trustbased 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.

A Protocol Model of S3 Computing Designed for Learning Community Platform of College Teachers

“…According to [10][11], nodes of low reputation will be randomly distributed among all groups if all nodes are randomly distributed among groups of size √ . For , the distribution of nodes is based on learning communities.…”

On Constrained Adding Friends in Social Networks

“…These networks constitute live platforms exploited by huge number of users for performing largescale computations such as conducting polls about political issues and seeking precise information on huge graph databases. To preserve data privacy during the running of these computations, recent works [8,9,10,12,27] use a simple secret sharing scheme which allows users to obfuscate their inputs. For instance, [7,9,10,12] proposed distributed polling protocols in social networks without requiring cryptographic system.…”

On the Concept of Trust in Online Social Networks

“…The decentralization is provided by the use of peer-to-peer technology. The work presented in [19] describes a new application of threshold-based secret sharing in a distributed OSN. The developed mechanism will select the most reliable delegates based on an effective trust measure.…”