A Lightweight Privacy Protection User Authentication and Key Agreement Scheme Tailored for the Internet of Things Environment: LightPriAuth

Algorithm 2

( Role of the Sensor)

let processSensor(sidj: bitstring) =

  ( registration phase of the sensor )

  out(scSensor,sidj);

 in (scSensor,xj: bitstring);

  ( Real start of the role )

 ( Message 2)

 in(csg,(A:G,m3:bitstring,T2:bitstring));

 ( Message 3)

 if (m3) = hash(con(g2h(A),con(sidj,con(xj,T2)))) then

  event acceptSensor(xj);

 new k2:exponent;

 let B = exp (g, k2) in

 let skijs = hash(g2h(exp (A, k2))) in

 let m4 = hash(con(g2h(B),con(skijs,g2h(A)))) in

 let m5 = hash(con(xj,con(m3,con(m4,g2h(B))))) in

 out(csg,(B,m4,m5));

  event termSensor(xj).