1 changed files with 183 additions and 0 deletions
			
			
		| @ -0,0 +1,183 @@ | |||
| // CROWDS [Reiter,Rubin] | |||
| // Vitaly Shmatikov, 2002 | |||
| 
 | |||
| // Note: | |||
| // Change everything marked CWDSIZ when changing the size of the crowd | |||
| // Change everything marked CWDMAX when increasing max size of the crowd | |||
| 
 | |||
| dtmc | |||
| 
 | |||
| // Probability of forwarding | |||
| const double PF = 0.8; | |||
| 
 | |||
| // Probability that a crowd member is bad | |||
| const double  badC = 0.091; | |||
| // const double  badC = 0.167; | |||
| 
 | |||
| const int TotalRuns=3; // Total number of protocol runs to analyze | |||
| const int CrowdSize=4; // CWDSIZ: actual number of good crowd members | |||
| const int MaxGood=20; // CWDMAX: maximum number of good crowd members | |||
| 
 | |||
| // Process definitions | |||
| module crowds | |||
| 
 | |||
| 	// Auxiliary variables | |||
| 	launch:   bool init true;       // Start modeling? | |||
| 	new:      bool init false;      // Initialize a new protocol instance? | |||
| 	runCount: [0..TotalRuns] init TotalRuns;   // Counts protocol instances | |||
| 	start:    bool init false;      // Start the protocol? | |||
| 	run:      bool init false;      // Run the protocol? | |||
| 	lastSeen: [0..MaxGood] init MaxGood;   // Last crowd member to touch msg | |||
| 	good:     bool init false;      // Crowd member is good? | |||
| 	bad:      bool init false;      //              ... bad? | |||
| 	recordLast: bool init false;    // Record last seen crowd member? | |||
| 	badObserve: bool init false;    // Bad members observes who sent msg? | |||
| 	deliver:  bool init false;      // Deliver message to destination? | |||
| 	done:     bool init false;      // Protocol instance finished? | |||
| 
 | |||
| 	// Counters for attackers' observations | |||
| 	// CWDMAX: 1 counter per each good crowd member | |||
| 	observe0:  [0..TotalRuns] init 0; | |||
| 	observe1:  [0..TotalRuns] init 0; | |||
| 	observe2:  [0..TotalRuns] init 0; | |||
| 	observe3:  [0..TotalRuns] init 0; | |||
| 	observe4:  [0..TotalRuns] init 0; | |||
| 	observe5:  [0..TotalRuns] init 0; | |||
| 	observe6:  [0..TotalRuns] init 0; | |||
| 	observe7:  [0..TotalRuns] init 0; | |||
| 	observe8:  [0..TotalRuns] init 0; | |||
| 	observe9:  [0..TotalRuns] init 0; | |||
| 	observe10: [0..TotalRuns] init 0; | |||
| 	observe11: [0..TotalRuns] init 0; | |||
| 	observe12: [0..TotalRuns] init 0; | |||
| 	observe13: [0..TotalRuns] init 0; | |||
| 	observe14: [0..TotalRuns] init 0; | |||
| 	observe15: [0..TotalRuns] init 0; | |||
| 	observe16: [0..TotalRuns] init 0; | |||
| 	observe17: [0..TotalRuns] init 0; | |||
| 	observe18: [0..TotalRuns] init 0; | |||
| 	observe19: [0..TotalRuns] init 0; | |||
| 	 | |||
| 	[] launch -> (new'=true) & (runCount'=TotalRuns) & (launch'=false); | |||
| 	// Set up a new protocol instance | |||
| 	[] new & runCount>0 -> (runCount'=runCount-1) & (new'=false) & (start'=true); | |||
| 	 | |||
| 	// SENDER | |||
| 	// Start the protocol | |||
| 	[] start -> (lastSeen'=0) & (run'=true) & (deliver'=false) & (start'=false); | |||
| 	 | |||
| 	// CROWD MEMBERS | |||
| 	// Good or bad crowd member? | |||
| 	[] !good & !bad & !deliver & run -> | |||
| 	             1-badC : (good'=true) & (recordLast'=true) & (run'=false) + | |||
| 	               badC : (bad'=true)  & (badObserve'=true) & (run'=false); | |||
| 
 | |||
| 	// GOOD MEMBERS | |||
| 	// Forward with probability PF, else deliver | |||
| 	[] good & !deliver & run -> PF : (good'=false) + 1-PF : (deliver'=true); | |||
| 	// Record the last crowd member who touched the msg; | |||
| 	// all good members may appear with equal probability | |||
| 	//    Note: This is backward.  In the real protocol, each honest | |||
| 	//          forwarder randomly chooses the next forwarder. | |||
| 	//          Here, the identity of an honest forwarder is randomly | |||
| 	//          chosen *after* it has forwarded the message. | |||
| 	[] recordLast & CrowdSize=2 -> | |||
| 	        1/2 : (lastSeen'=0) & (recordLast'=false) & (run'=true) + | |||
| 	        1/2 : (lastSeen'=1) & (recordLast'=false) & (run'=true); | |||
| 	[] recordLast & CrowdSize=4 -> | |||
| 	        1/4 : (lastSeen'=0) & (recordLast'=false) & (run'=true) + | |||
| 	        1/4 : (lastSeen'=1) & (recordLast'=false) & (run'=true) + | |||
| 	        1/4 : (lastSeen'=2) & (recordLast'=false) & (run'=true) + | |||
| 	        1/4 : (lastSeen'=3) & (recordLast'=false) & (run'=true); | |||
| 	[] recordLast & CrowdSize=5 -> | |||
| 	        1/5 : (lastSeen'=0) & (recordLast'=false) & (run'=true) + | |||
| 	        1/5 : (lastSeen'=1) & (recordLast'=false) & (run'=true) + | |||
| 	        1/5 : (lastSeen'=2) & (recordLast'=false) & (run'=true) + | |||
| 	        1/5 : (lastSeen'=3) & (recordLast'=false) & (run'=true) + | |||
| 	        1/5 : (lastSeen'=4) & (recordLast'=false) & (run'=true); | |||
| 	[] recordLast & CrowdSize=10 -> | |||
| 	        1/10 : (lastSeen'=0) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=1) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=2) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=3) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=4) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=5) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=6) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=7) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=8) & (recordLast'=false) & (run'=true) + | |||
| 	        1/10 : (lastSeen'=9) & (recordLast'=false) & (run'=true); | |||
| 	[] recordLast & CrowdSize=15 -> | |||
| 	        1/15 : (lastSeen'=0)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=1)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=2)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=3)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=4)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=5)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=6)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=7)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=8)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=9)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=10) & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=11) & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=12) & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=13) & (recordLast'=false) & (run'=true) + | |||
| 	        1/15 : (lastSeen'=14) & (recordLast'=false) & (run'=true); | |||
| 	[] recordLast & CrowdSize=20 -> | |||
| 	        1/20 : (lastSeen'=0)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=1)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=2)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=3)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=4)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=5)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=6)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=7)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=8)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=9)  & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=10) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=11) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=12) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=13) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=14) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=15) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=16) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=17) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=18) & (recordLast'=false) & (run'=true) + | |||
| 	        1/20 : (lastSeen'=19) & (recordLast'=false) & (run'=true); | |||
| 	 | |||
| 	// BAD MEMBERS | |||
| 	// Remember from whom the message was received and deliver | |||
| 	// CWDMAX: 1 rule per each good crowd member | |||
| 	[] lastSeen=0  & badObserve & observe0 <TotalRuns -> (observe0' =observe0 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=1  & badObserve & observe1 <TotalRuns -> (observe1' =observe1 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=2  & badObserve & observe2 <TotalRuns -> (observe2' =observe2 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=3  & badObserve & observe3 <TotalRuns -> (observe3' =observe3 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=4  & badObserve & observe4 <TotalRuns -> (observe4' =observe4 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=5  & badObserve & observe5 <TotalRuns -> (observe5' =observe5 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=6  & badObserve & observe6 <TotalRuns -> (observe6' =observe6 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=7  & badObserve & observe7 <TotalRuns -> (observe7' =observe7 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=8  & badObserve & observe8 <TotalRuns -> (observe8' =observe8 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=9  & badObserve & observe9 <TotalRuns -> (observe9' =observe9 +1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=10 & badObserve & observe10<TotalRuns -> (observe10'=observe10+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=11 & badObserve & observe11<TotalRuns -> (observe11'=observe11+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=12 & badObserve & observe12<TotalRuns -> (observe12'=observe12+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=13 & badObserve & observe13<TotalRuns -> (observe13'=observe13+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=14 & badObserve & observe14<TotalRuns -> (observe14'=observe14+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=15 & badObserve & observe15<TotalRuns -> (observe15'=observe15+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=16 & badObserve & observe16<TotalRuns -> (observe16'=observe16+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=17 & badObserve & observe17<TotalRuns -> (observe17'=observe17+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=18 & badObserve & observe18<TotalRuns -> (observe18'=observe18+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 	[] lastSeen=19 & badObserve & observe19<TotalRuns -> (observe19'=observe19+1) & (deliver'=true) & (run'=true) & (badObserve'=false); | |||
| 
 | |||
| 	// RECIPIENT | |||
| 	// Delivery to destination | |||
| 	[] deliver & run -> (done'=true) & (deliver'=false) & (run'=false) & (good'=false) & (bad'=false); | |||
| 	// Start a new instance | |||
| 	[] done -> (new'=true) & (done'=false) & (run'=false) & (lastSeen'=MaxGood); | |||
| 	 | |||
| endmodule | |||
| 
 | |||
| 
 | |||
| label "observeIGreater1" = observe1>1|observe2>1|observe3>1; | |||
| label "observeOnlyTrueSender" = observe0>1 & observe1<=1 & observe2<=1 & observe3<=1; | |||
| 
 | |||
| 
 | |||
						Write
						Preview
					
					
					Loading…
					
					Cancel
						Save
					
		Reference in new issue