Research On Dynamic Active Shield Technology Against Shield Rerouting Attack

We are now living in a world of globalization and information explosion,no single country can develop their politics,economy,science,and military without the help of information.On the other side,because human society is highly dependent on information technology and electronics,people attach increasingly great importance to the information security problem.Security chips are the most useful tool to deal with information security problem,and they are widly used in information industry.Active shield is a typical physical protection modula for security chips.Active shield is a sensor mesh devised and implemented on top of most security chips or in a secure embedded system as a good protection for circuits and sensitive data stored in the chips.It is one of the most effective annoyances to microprobing attackers.But,shield rerouting attack can defeat active shield by disclosing the geometry structure of the shield(with the help of reverse engineering),causing a short circuit of the sensor mesh.This paper proposes a dynamic active shield to resist shield rerouting attack.The dynamic active shield is a sensor mesh which contains some routing nodes and connecting metal lines between adjacent nodes.Changing the connection statuses of routing nodes result in different paths of the shield sensor mesh.The dynamic active shield increases the security of the circuits and defeats the shield rerouting attack by changing the path of the sensor mesh every few clock cycles,making it more difficult to distinguish the geometry structure of the shield sensor mesh.To make the sensor mesh of shield dynamic changes,we propose a shield controller to output control signals periodically.The control signals are predesigned that can control the routing nodes connected into a Hamiltonian path.Outputting different control signals to the shield will change the connection of shield 's sensor mesh.At last,the experiment results show that dynamic active shield can improve physical security of integrated circuits,and the area and p ower consumption are affordable for most security chips.