scyther/gui/Protocols/denning-sacco-lowe.spdl
2012-04-26 16:40:01 +02:00

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# Lowe modified Denning-Sacco shared key
#
# Modelled after the description in the SPORE library
# http://www.lsv.ens-cachan.fr/spore/denningSaccoLowe.html
#
# Note:
# According to SPORE there are no attacks on this protocol, scyther
# finds one however. This has to be investigated further.
usertype Key;
usertype SessionKey;
usertype TimeStamp;
usertype ExpiredTimeStamp;
usertype PseudoFunction;
const dec: PseudoFunction;
const Fresh: Function;
const Compromised: Function;
protocol denningSacco-Lowe(I,R,S)
{
role I
{
var W: Ticket;
var Kir: SessionKey;
var T: TimeStamp;
var Nr: Nonce;
send_1(I,S, I,R );
recv_2(S,I, {R, Kir, T, W}k(I,S) );
send_3(I,R, W);
recv_4(R,I, {Nr}Kir);
send_5(I,R, {{Nr}dec}Kir);
claim_I1(I,Niagree);
claim_I2(I,Nisynch);
claim_I3(I,SKR,Kir);
claim_I4(I,Empty,(Fresh,Kir));
}
role R
{
var Kir: SessionKey;
var T: TimeStamp;
fresh Nr: Nonce;
recv_3(I,R, {Kir,I,T}k(R,S));
send_4(R,I, {Nr}Kir);
recv_5(I,R, {{Nr}dec}Kir);
claim_R1(R,Niagree);
claim_R2(R,Nisynch);
claim_R3(R,Secret,Kir);
claim_R4(R,Empty,(Fresh,Kir));
}
role S
{
var W: Ticket;
fresh Kir: SessionKey;
fresh T: TimeStamp;
recv_1(I,S, I,R );
send_2(S,I, {R, Kir, T, {Kir, I,T}k(R,S)}k(I,S));
}
}