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

Algorithm 7

role session(Ui, Sj, GW: agent,

     Kdi,Kei, Kxj,Xgwn: symmetric_key,

     H: hash_func,

     P: text

     )

def=

 local  SSG,RSG,

     SUG,RUG:channel(dy)

 composition

  user(Ui,Sj,GW, Kdi,Kei,     H,P, SUG,RUG)

⋀ sensor(Ui,Sj,GW, Kxj,       H,P, SSG,RSG)

⋀ gateway(Ui,Sj,GW, Kdi,Kei,Kxj,Xgwn, H, SUG,RUG,SSG,RSG)

end role