Enabling Secure Secret Sharing in Distributed Online Social Networks

—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 vari...

• Type: Conference
• Year: 2009
• Where: ACSAC
• Authors: Le-Hung Vu, Karl Aberer, Sonja Buchegger, Anwitaman Datta
• Keywords: ACSAC 2009, Online Social Networks, Reliable Delegates, Security Privacy, Threshold-based Secret Sharing