90 lines
1.7 KiB
Plaintext
90 lines
1.7 KiB
Plaintext
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# Buttyan Nagy Vajda protocol 1 (3-party)
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#
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# Modelled after the description in the paper
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# "Efficient multi-party challenge-response protocols for entity
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# authentication"
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#
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# Attacks:
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# Does not satisfy ni-agree, because when Alice in the A role terminates
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# it cannot be sure that the agent in role B is aware of having sent a
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# reply for Alice.
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# A type flaw attack exists in which there are only two agents active.
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#
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secret k: Function;
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protocol intruderhelp(Swap)
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{
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role Swap
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{
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var T: Ticket;
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var A,B: Agent;
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read_1(Swap,Swap, { T }k(A,B) );
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send_2(Swap,Swap, { T }k(B,A) );
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}
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}
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protocol bunava1(A,B,C)
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{
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role A
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{
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const ra: Nonce;
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var rb,rc: Nonce;
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send_1(A,B, ra);
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read_3(C,A, rc,{C,rb,B,ra}k(A,C) );
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send_4(A,B, {A,rc,C,rb}k(A,B) );
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claim_A1(A, Niagree);
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claim_A2(A, Nisynch);
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}
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role B
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{
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const rb: Nonce;
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var ra,rc: Nonce;
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read_1(A,B, ra);
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send_2(B,C, rb,{B,ra}k(B,C) );
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read_4(A,B, {A,rc,C,rb}k(A,B) );
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send_5(B,C, {B,A,rc}k(B,C) );
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claim_B1(B, Niagree);
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claim_B2(B, Nisynch);
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}
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role C
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{
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const rc: Nonce;
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var ra,rb: Nonce;
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read_2(B,C, rb,{B,ra}k(B,C) );
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send_3(C,A, rc,{C,rb,B,ra}k(A,C) );
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read_5(B,C, {B,A,rc}k(B,C) );
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claim_C1(C, Niagree);
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claim_C2(C, Nisynch);
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}
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}
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const Alice,Bob,Charlie,Eve: Agent;
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untrusted Eve;
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const ne: Nonce;
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compromised k(Alice,Eve);
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compromised k(Bob,Eve);
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compromised k(Charlie,Eve);
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compromised k(Eve,Alice);
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compromised k(Eve,Bob);
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compromised k(Eve,Charlie);
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# General scenario, 2 parallel runs of the protocol
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run bunava1.A(Agent,Agent,Agent);
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run bunava1.B(Agent,Agent,Agent);
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run bunava1.C(Agent,Agent,Agent);
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run bunava1.A(Agent,Agent,Agent);
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run bunava1.B(Agent,Agent,Agent);
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run bunava1.C(Agent,Agent,Agent);
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