const pk: Function; secret sk: Function; inversekeys (pk,sk); protocol carkeyni(I,R) { role I { fresh ni: Nonce; send_1(I,R, {R,ni}sk(I) ); } role R { var ni: Nonce; read_1(I,R, {R,ni}sk(I) ); claim_2(R,Nisynch); } }