Topology generation algorithm of weighted directed network based on the triad formation rule was proposed. The directed edges were added to the network using weight preferential attachment rule and triad formation rule; moreover, the weights of network edges were evolved dynamically to realize the asymmetric interaction among nodes. The simulation results show that, the network topology, which is generated by the modeling algorithm for weighted directed network topology based on the triad formation rule, is consistent with topology characteristics showed by topology structures in the real network environment. Meanwhile, it has good controllability of the clustering coefficient.

This paper analyzed and compared the advantages and disadvantages of the existing identity certification schemes for VPN connection, and pointed out the advantages of using fingerprint information for VPN identity certification. An identity certification scheme for VPN connection based on fingerprint identification was proposed. The paper also analyzed the security of the scheme, and introduced the application effect in the practical project. The scheme can prevent middle attack, tampering and falsifying information. It has forward-security, and is of better security than the existing schemes.