Sybil prevention
The mechanisms to prevent against Sybil attacks are to utilize
identity certificates [11]. The basic idea is very simple. The setup
server, before deployment, assigns each sensor node some unique
information. The server then creates an identity certificate
binding this node‟s identity to the assigned unique information,
and downloads this information into the node. To securely
demonstrate its identity, a node first presents its identity
certificate, and then proves that it possesses or matches the