Score:0

Protocol security

hk flag

Protocol

This protocol is designed to establish a session key K'AB between two parties without the interaction with a server. In this case, the key KAB is a long-term key shared between Alice and Bob. I am supposed to create an attack, where i imitate Bob. I think it is a problem with the missing verification of Bob. I'm stuck with this task for a couple of days and can't get a proper answer. Please help

Daniel S avatar
ru flag
HINT: Is the protocol supposed to work both ways? If so, what happens if you try to set up two sessions, one as initiator and one as responder?
azn  avatar
hk flag
Do you mean a session where bob acts as initiator?
Daniel S avatar
ru flag
Yes, set up two sessions: one where your pretending to be Bob as initiator and one where you're pretending to be Bob as resonder.
azn  avatar
hk flag
I'm thinking about saving the Nonce of Alice when being a responder and then use the same Nonce initiating. Am I on the right track?
azn  avatar
hk flag
So if I'm inititing, I get: {NB,K'AB}KAB, N'A. Can I then reuse this information when I am the responder, assuming the Nonces are the same?
azn  avatar
hk flag
Thanks for your help! I was trying to figure out a way to get the session key somehow, but it was the wrong approach.
I sit in a Tesla and translated this thread with Ai:

mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.