/* * Boyd fix for NS(L) * * From the paper "Towards Extensional Goals in Authentication * Protocols" * * Broken. Best shown by attack id 4. */ const pk: Function; secret sk: Function; inversekeys (pk,sk); const hash: Function; secret unhash: Function; inversekeys (hash,unhash); protocol boydNS(I,R) { role I { const ni: Nonce; var nr: Nonce; send_1(I,R, {ni}pk(R),I ); read_2(R,I, {nr}pk(I),hash(ni,R) ); send_3(I,R, hash(nr, I,R) ); claim_i1(I,Secret,ni); claim_i2(I,Secret,nr); claim_i3(I,Niagree); claim_i4(I,Nisynch); } role R { var ni: Nonce; const nr: Nonce; read_1(I,R, {ni}pk(R),I ); send_2(R,I, {nr}pk(I),hash(ni,R) ); read_3(I,R, hash(nr, I,R) ); claim_r1(R,Secret,ni); claim_r2(R,Secret,nr); claim_r3(R,Niagree); claim_r4(R,Nisynch); } } const Alice,Bob,Eve: Agent; untrusted Eve; const ne: Nonce; compromised sk(Eve); run boydNS.I(Agent,Agent); run boydNS.R(Agent,Agent);