scyther/protocols/misc/yahalom-lowe.spdl

/*
 * Yahalom Lowe
 * As in Sjouke's list
 */

usertype Sessionkey;

secret k : Function;

const kee: Sessionkey;

protocol yahalomlowe(I,R,S)
{
	role I
	{
		fresh ni: Nonce;
		var nr: Nonce;
		var kir: Sessionkey;

		send_1(I,R, I,ni);
		read_3(S,I, {R,kir,ni,nr}k(I,S) );
		send_5(I,R, {I,R,S,nr}kir );

		claim_8(I, Secret,kir);
		claim_9(I, Niagree);
		claim_10(I, Nisynch);
	}

	role R
	{
		fresh nr: Nonce;
		var ni: Nonce;
		var kir: Sessionkey;

		read_1(I,R, I,ni);
		send_2(R,S, {I,ni,nr}k(R,S) );
		read_4(S,R, {I,kir}k(R,S) );
		read_5(I,R, {I,R,S,nr}kir );
		claim_11(R, Secret,kir);
		claim_12(R, Nisynch);
		claim_13(R, Niagree);
	}

	role S
	{
		fresh kir: Sessionkey;
		var ni,nr: Nonce;

		read_2(R,S, {I,ni,nr}k(R,S) );
		send_3(S,I, {R,kir,ni,nr}k(I,S) );
		send_4(S,R, {I,kir}k(R,S) );
	}
}