| role rserver (RC, Ui, ASj: agent, | | SKey1 : symmetric_key, | | SKey2 : symmetric_key, | | H, MUL, SUB: hash_func, | | Snd, Rcv: channel(dy) ) | | played_by RC | | def= | | local State : nat, | | IDj, IDi, Ej, P, Q, N, W, Dj, G, Yj: text, | | Ai, Bi, Ci, Di, Ei, Fi, X, M1, M2, M3: message, | | Inc : hash_func | | const user_rserver, rserver_aserver, | | aserver_user, sec1, sec2, sec3, sec4, sec5, | | sec6 : protocol_id | | init State ≔0 | | transition | | 1. State = 0 Rcv(IDj＇}_SKey1) | | State＇ ≔ 1 Ej＇ ≔ new() | | Dj＇ ≔new() | | P＇ ≔new() | | Q＇ ≔new() | | N＇ ≔ MUL(P＇,Q＇) | | W＇ ≔ MUL(SUB(P＇,1), SUB(Q＇,1)) | | Yj＇ ≔ h(Ej＇.Dj＇) | | Snd(Ej＇.Dj＇}_SKey1) | | secret(Dj＇}, sec4, ASj,RC}) | | secret(P＇,Q＇}, sec5, RC}) | | 2. State = 1 Rcv(IDi.Ai＇}_SKey2) | | State＇ ≔ 2 Bi＇ ≔ exp(G,MUL(X,IDi)) | | Ci＇ ≔ exp(IDi,Ai) | | Di＇ ≔ xor(Bi＇,Ci＇) | | Ei＇ ≔h(Ai.Bi＇) | | Fi＇ ≔IDi}_X | | Snd(Di＇.Ei＇.Fi＇.N}_SKey2) | | 3. State = 2 Rcv(M1＇.M2＇.Fi.IDj) | | State＇ ≔ 3 M3＇ ≔ xor(Yj,IDi) | | Snd(Ej.M3＇) | | end role |
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