andr3/scyther
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- Add a dummy role in andrew-ban-concrete to work around the key symmetry

Browse Source 
issue (k(I,R) != k(R,I))
- Fix a typo in splice-as-cj
This commit is contained in:
gijs 2005-06-14 12:24:42 +00:00
parent 013afc99aa
commit b212e0b1ec
2 changed files with 15 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
spdl/SPORE/andrew-ban-concrete.spdl
View File

@ -6,11 +6,8 @@
# Note: # Note:
# The shared key between I and R is modelled as k(I,R) currently # The shared key between I and R is modelled as k(I,R) currently
# there is no way to express that this key is equal to k(R,I) # there is no way to express that this key is equal to k(R,I)
# So it is possile that certain attacks that use this property are not found # In order to overcome this a 'dummy' role X has been hadded that recrypts
# # a given term crypted with k(I,R) with k(R,I)
# Note:
# The attack mentioned in SPORE is not found because of the property in the
# previous note
# #
# Note: # Note:
# Read 4 by the Initatior has been placed after the synchronisation claim # Read 4 by the Initatior has been placed after the synchronisation claim
@ -22,8 +19,17 @@
usertype SessionKey; usertype SessionKey;
secret k: Function; secret k: Function;
protocol andrewConcrete(I,R) protocol andrewConcrete(I,R,X)
{ {
# Role added to work around the symmetry problems where k(I,R) != k(R,I)
role X
{
var T: Ticket;
read_X1(X,X, {T}k(I,R));
send_X2(X,X, {T}k(R,I));
}
role I role I
{ {
const ni: Nonce; const ni: Nonce;

6
spdl/SPORE/splice-as-cj.spdl
View File

@ -73,9 +73,9 @@ untrusted Eve;
const ne: Nonce; const ne: Nonce;
compromised sk(Eve); compromised sk(Eve);
run spliceASCJI(Agent,Agent,Agent); run spliceASCJ.I(Agent,Agent,Agent);
run spliceASCJR(Agent,Agent,Agent); run spliceASCJ.R(Agent,Agent,Agent);
run spliceASCJS(Agent,Agent,Agent); run spliceASCJ.S(Agent,Agent,Agent);
#run spliceASCJ.I(Alice,Bob,Simon); #run spliceASCJ.I(Alice,Bob,Simon);
#run spliceASCJ.R(Alice,Bob,Simon); #run spliceASCJ.R(Alice,Bob,Simon);