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

Box 2

role sensor (Ui, Sj, GW  : agent,

Kxj: symmetric_key,

H: hash_func,

P: text,

SND_US,RCV_US,SND_SG,RCV_SG: channel(dy))

played_by Sj

def=

local State  : nat,

T1,T2,K2, Na,Nb,SK  : text,

Y,X,Z  : message

const user_sensor_sk:protocol_id

initState 1

transition

(1) State= 1 RCV_US(Na.Y.Z.T1) =>

State ≔ 3 T2 ≔ new()

K2 ≔ new()

Nb ≔ exp(P,K2)

SND_SG( Na

.Y

.Z

.T1

.Nb

.H(Nb.Z.Kxj.T2)

.T2 )

(2) State = 2 RCV_SG( H(Na.Kxj.H(Nb.Z.Kxj.T2).T2)

.X ) =>

State ≔ 4 SK ≔ H(exp(Na,K2))

witness(Sj,Ui,user_sensor_sk,SK)

request(Sj,Ui,user_sensor_sk,SK)

SND_US(Nb

.X)

end role