scyther/spdl/ns3.spdl

/* 
 * Needham-Schroeder protocol
 */

// PKI infrastructure

const pk: Function;
secret sk: Function;
inversekeys (pk,sk);

// The protocol description

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

		send_1(I,R, {I,ni}pk(R) );
		read_2(R,I, {ni,nr}pk(I) );
		send_3(I,R, {nr}pk(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, {I,ni}pk(R) );
		send_2(R,I, {ni,nr}pk(I) );
		read_3(I,R, {nr}pk(R) );
		claim_r1(R,Secret,ni);
		claim_r2(R,Secret,nr);
		claim_r3(R,Niagree);
		claim_r4(R,Nisynch);
	}
}

// The agents in the system

const Alice,Bob: Agent;

// An untrusted agent, with leaked information

const Eve: Agent;
untrusted Eve;
const ne: Nonce;
compromised sk(Eve);

// The runs (only needed for the modelchecker algorithm)

run ns3.I(Agent,Agent);
run ns3.R(Agent,Agent);
run ns3.I(Agent,Agent);
run ns3.R(Agent,Agent);
run ns3.I(Agent,Agent);
run ns3.R(Agent,Agent);
run ns3.I(Agent,Agent);
run ns3.R(Agent,Agent);
run ns3.I(Agent,Agent);
run ns3.R(Agent,Agent);