SessionKeys.spdl

hashfunction  hashed;
hashfunction sharedkey;
usertype Message;
usertype SessionKey;

protocol KeyExchange(Monitor,CloudServer)
{
	role Monitor

	{

		fresh MonitorValue  : Nonce;
		var CloudServerValue : Nonce;

		fresh info : Message;
		fresh sharedkey: SessionKey;


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

	{

		var MonitorValue: Nonce;
		fresh CloudServerValue: Nonce;

		var info: Message;
		var sharedkey: SessionKey;

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

		claim_CloudServer1(CloudServer,Niagree);
		claim_CloudServer2(CloudServer,Nisynch);
		claim_CloudServer3(CloudServer,  Secret, info);

	}
}