Abstract
We study the security of password protocols against off-line dictionary attacks. In addition to the standard adversary abilities, we also consider further cryptographic advantages given to the adversary when considering the password protocol being instantiated with particular encryption schemes. We work with the applied pi-calculus of Abadi and Fournet, in which the (new) adversary abilities are modelled as equations between terms. As case studies, we analyse the Encrypted Password Transmission (EPT) protocol of Halevi and Krawczyk, and the wellknown Encrypted Key (EKE) of Bellovin and Merritt. In the latter, we find an attack that arises when considering the ability of distinguishing ciphertexts from random noise. We propose a modification to EKE that prevents this attack.
Original language | English |
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Title of host publication | Proceedings of the 2nd International Workshop on Security Issues with Petri Nets and other Computational Models (WISP 2004) |
Editors | Nadia Busi, Roberto Gorrieri, Fabio Martinelli |
Place of Publication | Amsterdam |
Publisher | Elsevier |
Pages | 47-63 |
Number of pages | 17 |
DOIs | |
Publication status | Published - Jun 2004 |
Event | 2nd International Workshop on Security Issues with Petri Nets and other Computational Models, WISP 2004 - Bologna, Italy Duration: 26 Jun 2004 → 26 Jun 2004 Conference number: 2 |
Publication series
Name | Electronic Notes in Theoretical Computer Science |
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Publisher | Elsevier |
Volume | 121 |
ISSN (Print) | 1571-0661 |
Workshop
Workshop | 2nd International Workshop on Security Issues with Petri Nets and other Computational Models, WISP 2004 |
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Abbreviated title | WISP |
Country | Italy |
City | Bologna |
Period | 26/06/04 → 26/06/04 |
Other | June 26, 2004 |
Keywords
- SCS-Cybersecurity
- Password protocols
- Dictionary attacks
- Verification
- Pi calculus