Biblio
Users in social network are confronted with the risk of privacy leakage while sharing information with friends whose privacy protection awareness is poor. This paper proposes a security risk estimation framework of social network privacy, aiming at quantifying privacy leakage probability when information is spread to the friends of target users' friends. The privacy leakage probability in information spreading paths comprises Individual Privacy Leakage Probability (IPLP) and Relationship Privacy Leakage Probability (RPLP). IPLP is calculated based on individuals' privacy protection awareness and the trust of protecting others' privacy, while RPLP is derived from relationship strength estimation. Experiments show that the security risk estimation framework can assist users to find vulnerable friends by calculating the average and the maximum privacy leakage probability in all information spreading paths of target user in social network. Besides, three unfriending strategies are applied to decrease risk of privacy leakage and unfriending the maximum degree friend is optimal.