71 lines
1008 B
Plaintext
71 lines
1008 B
Plaintext
/*
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* Needham-Schroeder symmetric
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*/
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/* symmetric */
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usertype SessionKey;
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secret k: Function;
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/* agents */
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/* untrusted e */
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untrusted e;
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const kee: SessionKey;
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compromised k(e,e);
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compromised k(e,a);
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compromised k(e,b);
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compromised k(a,e);
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compromised k(b,e);
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/* {}x used for public (invertible) function modeling */
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usertype PseudoFunction;
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const succ: PseudoFunction;
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usertype Ticket;
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protocol nssymmetric(A,S,B)
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{
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role A
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{
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fresh na: Nonce;
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var T: Ticket;
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var kab: SessionKey;
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var nb: Nonce;
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send_1(A,S, A,B,na );
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recv_2(S,A, { na,B,kab,T }k(A,S) );
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send_3(A,B, T );
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recv_4(B,A, { nb }kab );
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send_5(A,B, { {nb}succ }kab );
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claim_6(A, Secret, kab);
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}
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role S
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{
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fresh kab: SessionKey;
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var na: Nonce;
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recv_1(A,S, A,B,na );
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send_2(S,A, { na,B,kab, { kab,A }k(B,S) }k(A,S) );
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}
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role B
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{
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var kab: SessionKey;
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fresh nb: Nonce;
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recv_3(A,B, { kab,A }k(B,S) );
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send_4(B,A, { nb }kab );
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recv_5(A,B, { {nb}succ }kab );
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claim_7(B, Secret, kab);
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}
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}
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