/* 
 * Needham-Schroeder protocol
 */

// The protocol description

protocol ns3(I,R)
{
	role I
	{
		fresh ni: Nonce;
		var nr: Nonce;

		send_1(I,R, {ni,I}pk(R) );
		recv_2(R,I, {ni,nr}pk(I) );
		claim(I,Running,R,ni,nr);
		send_3(I,R, {nr}pk(R) );

		claim(I,Secret,ni);
		claim(I,Secret,nr);
		claim(I,Alive);
		claim(I,Commit,R,ni,nr);
		claim(I,Niagree);
		claim(I,Nisynch);
	}	
	
	role R
	{
		var ni: Nonce;
		fresh nr: Nonce;

		recv_1(I,R, {ni,I}pk(R) );
		claim(R,Running,I,ni,nr);
		send_2(R,I, {ni,nr}pk(I) );
		recv_3(I,R, {nr}pk(R) );

		claim(R,Secret,ni);
		claim(R,Secret,nr);
		claim(R,Alive);
		claim(R,Commit,I,ni,nr);
		claim(R,Niagree);
		claim(R,Nisynch);
	}
}