Table 4 Sensor node simulation process

(*processsensornode*)

let processsensornode = 

  in(ch2,SIDj:bitstring);

  new b:bitstring;

  new T2:bitstring;

  let Ts = G(b)in

  let M2 = XOR(Ts,hash(concat(GWNPSj,T2))) in

  let M3 = hash(concat(SIDj,concat(GWNPSj,concat(Ts,T2)))) in

  out(ch2,(SIDj,M2,M3,T2));

  in(ch2,(M4:bitstring,M5:bitstring,T3:bitstring));

  let (Tu:bitstring,UIDi:bitstring,SIDj:bitstring,T3:bitstring) = D(GWNPSj,M4) in

  let M5' = hash(concat(GWNPSj,concat(Tu,concat(UIDi,concat(SIDj,T3))))) in

  if M5 = M5' then

  event sensorAccept(gwn);

  let SKsu = hash(concat(GK(b,Ts),concat(UIDi,concat(SIDj,T3)))) in

  new T4:bitstring;

  let Vs = hash(concat(SKsu,T4))in

  out(ch3,(Vs,T4));

  in(ch3,(Vu:bitstring,T5:bitstring));

  let Vu' = hash(concat(SKsu,T5))in

  if Vu' = Vu then

  event Sksuccessful(ui,sj)