Research of network safety path and secure network coding under wiretapping

First,using the idea of directed graph spanning tree algorithm,the algorithm for safety path searching in single source single sink network under wiretapping is extended to the situation of single source multi-sink network.Then,in the context of algebraic construction of linear network coding,a detailed analysis of multicast network under wiretapping attack is given.Finally,an improved algebraic construction algorithm for linear network coding which combines the idea of weak network coding is proposed.With the using of this improved method,weak network security can be guaranteed at least,even if there is no safety path from the source to the sink.