Naslov
Bounded memory Dolev-Yao adversaries in collaborative systems

Autori
Kanovich, Max ; Ban Kirigin, Tajana ; Nigam, Vivek ; Scedrov, Andre

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Lecture Notes in Computer Science, Volume 6561 / Degano, Pierpaolo ; Etalle, Sandro and Guttman, Joshua D. - : Springer, 2011, 18-33

ISBN
978-3-642-19750-5

Skup
Formal Aspects of Security and Trust

Mjesto i datum
Pisa, Italija, 16.09.2010. - 17.09.2010

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Collaborative Systems ; Dolev-Yao intruders ; Complexity

Sažetak
This paper extends existing models for collaborative systems with confidentiality policies. We investigate how much damage can be done by insiders alone, without collusion with an outside adversary. In contrast to traditional intruder models, such as in protocol security, all the players inside our system, including potential adversaries, have similar capabilities. They have bounded storage capacity, that is, they can only remember at any moment a bounded number of facts. This is imposed technically by only allowing balanced actions, that is, actions that have the same number of facts in their pre and post conditions. On the other hand, the adversaries inside our system have many capabilities of the standard Dolev-Yao intruder, namely, they are able, within their bounded storage capacity, to compose, decompose, overhear, and intercept messages as well as create fresh values. We investigate the complexity of the decision problem of whether or not an adversary is able to discover secret data. We show that this problem is PSPACE-complete when all actions are balanced and can create fresh values. If we further impose the condition, called progressing, that in a run any instance of an action can be used at most once, then this new problem is NP-complete when actions are balanced and only a bounded number of fresh values can be created and it is PSPACE-hard when actions are balanced and any number of fresh values can be created. Finally, we return to traditional intruder models and demonstrate that protocol anomalies, such as the Lowe anomaly in the Needham-Schroeder public key exchange protocol, can also occur when the intruder is one of the insiders with bounded memory.

Izvorni jezik
Engleski

Znanstvena područja
Matematika, Računarstvo

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