src/HOL/Auth/Public.thy
changeset 2318 6d3f7c7f70b0
child 2451 ce85a2aafc7a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Auth/Public.thy	Thu Dec 05 18:07:27 1996 +0100
@@ -0,0 +1,66 @@
+(*  Title:      HOL/Auth/Public
+    ID:         $Id$
+    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
+    Copyright   1996  University of Cambridge
+
+Theory of Public Keys (common to all symmetric-key protocols)
+
+Server keys; initial states of agents; new nonces and keys; function "sees" 
+*)
+
+Public = Message + List + 
+
+consts
+  pubK    :: agent => key
+
+syntax
+  priK    :: agent => key
+
+translations
+  "priK x"  == "invKey(pubK x)"
+
+consts  (*Initial states of agents -- parameter of the construction*)
+  initState :: [agent set, agent] => msg set
+
+primrec initState agent
+        (*Agents know their private key and all public keys*)
+  initState_Server  "initState lost Server     =    
+ 		         insert (Key (priK Server)) (Key `` range pubK)"
+  initState_Friend  "initState lost (Friend i) =    
+ 		         insert (Key (priK (Friend i))) (Key `` range pubK)"
+  initState_Spy     "initState lost Spy        =    
+ 		         (Key``invKey``pubK``lost) Un (Key `` range pubK)"
+
+
+datatype  (*Messages, and components of agent stores*)
+  event = Says agent agent msg
+
+consts  
+  sees1 :: [agent, event] => msg set
+
+primrec sees1 event
+           (*Spy reads all traffic whether addressed to him or not*)
+  sees1_Says  "sees1 A (Says A' B X)  = (if A:{B,Spy} then {X} else {})"
+
+consts  
+  sees :: [agent set, agent, event list] => msg set
+
+primrec sees list
+  sees_Nil  "sees lost A []       = initState lost A"
+  sees_Cons "sees lost A (ev#evs) = sees1 A ev Un sees lost A evs"
+
+
+(*Agents generate "random" nonces.  These are uniquely determined by
+  the length of their argument, a trace.*)
+consts
+  newN :: "event list => nat"
+
+rules
+
+  (*Public keys are disjoint, and never clash with private keys*)
+  inj_pubK      "inj pubK"
+  priK_neq_pubK "priK A ~= pubK B"
+
+  newN_length   "(newN evs = newN evt) ==> (length evs = length evt)"
+
+end