hashfunction  hashed;
usertype Message;

protocol KeyExchange(Monitor,CloudServer)
{
	role Monitor

	{

		fresh MonitorValue  : Nonce;
		fresh Confirm: Message;
		var CloudServerValue : Nonce;

		send_1(Monitor,CloudServer,{Monitor,MonitorValue}pk(CloudServer));
		
		recv_2(CloudServer,Monitor, {CloudServerValue,hashed(MonitorValue),
		CloudServer}pk(Monitor));
		
		send_3(Monitor,CloudServer, hashed(CloudServerValue, Confirm));
		
		claim_Monitor1(Monitor,Niagree);
		claim_Monitor2(Monitor,Nisynch);
		claim_Monitor3(Monitor,  Secret, MonitorValue);
		claim_Monitor4(Monitor,  Secret, CloudServerValue);

	}	
	
	role CloudServer

	{

		var MonitorValue: Nonce;
		var Confirm: Message;
 		fresh CloudServerValue: Nonce;

		recv_1(Monitor,CloudServer,{Monitor,MonitorValue}pk(CloudServer));
		
		send_2(CloudServer,Monitor, {CloudServerValue,hashed(MonitorValue),
		CloudServer}pk(Monitor));
		
		recv_3(Monitor,CloudServer, hashed(CloudServerValue, Confirm));

		claim_CloudServer1(CloudServer,Niagree);
		claim_CloudServer2(CloudServer,Nisynch);
		claim_CloudServer3(CloudServer,  Secret, MonitorValue);
		claim_CloudServer4(CloudServer,  Secret, CloudServerValue);

	}
}