Authenticating Strangers in Fast Mixing Online Social Networks

Making new connections is a crucial service in current online social networks. However, such a service can also raise a big security concern. For example, two strangers become friends in the online social network and they want to communicate securely. The messages transmitted between them could be encrypted using their public keys and decrypted using their private keys. However, one can not determine whether this public key indeed belongs to the claimed user. In this paper, we design a system to authenticate two strangers in fast mixing online social networks. We make a thorough analysis on our system and show that there is a high probability of finding witness users in fast mixing social networks.