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

Box 3

role gateway (Ui, Sj, GW  : agent,

Kdi, Kxj: symmetric_key,

Kug  : symmetric_key,

H: hash_func,

SND_SG, RCV_SG: channel(dy))

played_by GW

def=

local State  : nat,

T1,T2,Na,Nb,IDi,SIDj  : text

const sk_User_gwn,sk_sensor_gwn,sc_sensor_id,sc_user_id:protocol_id

initState ≔ 5

transition

(1) State= 5 RCV_SG( Na

.xor((IDi.SIDj),Kug)

.H(Na.xor((IDi.SIDj),Kug).Kdi.T1)

.T1

.Nb

.H(Nb.H(Na.xor((IDi.SIDj),Kug).Kdi.T1).Kxj.T2)

.T2) =>

State ≔ 7 SND_SG(

H(Na.Kxj.H(Nb.H(Na.xor((IDi.SIDj),Kug).Kdi.T1).Kxj.T2).T2)

.H(Nb.Kdi.H(Na.xor((IDi.SIDj),Kug).Kdi.T1).Na.T1)

)

secret(IDi,sc_user_id,)

secret(SIDj,sc_sensor_id,)

end role