The study of PGP web of trust based on social network analysis

This paper aims to explore the patterns of online interaction of users of the pretty good privacy (PGP) algorithm to identify the most important and influential users in the social network. While PGP is widely used in protecting email privacy, there are some encryption defects that can raise users' concerns about data privacy and security. It is therefore essential to identify the most influential and active users who are trusted widely, getting numerous keys in the PGP web of trust. However, it is not always known whether the user actually gained trust from others or it is one who illegally forged the keys. In order to identify the most important users in the PGP network, social network analysis (SNA) is used to analyse their online interaction conditions. Along with the most traditional centrality analysis, a less frequent used K-means clustering analysis is also conducted to obtain more precise and accurate results. The SNA results show that: 1) PGP algorithm users' online interaction patterns are rather different, which include both frequent versus isolated; 2) people with higher centrality use the PGP algorithm more frequently and may become the target peeks to seek; 3) in the analysed network, all important nodes are in the same cluster when applying K-means model to divide the community.