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ABSTRACT
We revisit the venerable question of access credentials management, which concerns the techniques that we, humans with limited memory, must employ to safeguard our various access keys and tokens in a connected world. Although many existing solutions can be employed to protect a long secret using a short password, those solutions typically require certain assumptions on the distribution of the secret and/or the password, and are helpful against only a subset of the possible attackers. After briefly reviewing a variety of approaches, we propose a user-centric comprehensive model to capture the possible threats posed by online and offline attackers, from the outside and the inside, against the security of both the plaintext and the password. We then propose a few very simple protocols, adapted from the Ford-Kaliski server-assisted password generator and the Boldyreva unique blind signature in particular, that provide the best protection against all kinds of threats, for all distributions of secrets. We also quantify the concrete security of our approach in terms of online and offline password guesses made by outsiders and insiders, in the random-oracle model. The main contribution of this paper lies not in the technical novelty of the proposed solution, but in the identification of the problem and its model. Our results have an immediate and practical application for the real world: they show how to implement single-sign-on stateless roaming authentication for the internet, in a ad-hoc user-driven fashion that requires no change to protocols or infrastructure.
REFERENCES
Note: OCR errors may be found in this Reference List extracted from the full text article. ACM has opted to expose the complete List rather than only correct and linked references.
| |
1
|
Michel Abdalla, Mihir Bellare, Dario Catalano, Eike Kiltz, Tadayoshi Kohno, Tanja Lange, John Malone Lee, Gregory Neven, Pascal Paillier, and Haixia Shi. Searchable encryption revisited: Consistency properties, relation to anonymous IBE, and extensions. In Advances in Cryptology---CRYPTO 2005, pages 205--22, 2005.
|
| |
2
|
|
| |
3
|
Mihir Bellare, David Pointcheval, and Philip Rogaway. Authenticated key exchange secure against dictionary attacks. In Advances in Cryptology---EUROCRYPT 2000, pages 139--55, 2000.
|
| |
4
|
|
 |
5
|
|
| |
6
|
|
| |
7
|
|
| |
8
|
|
| |
9
|
|
| |
10
|
Dan Boneh, Giovanni Di Crescenzo, Rafail Ostrovsky, and Giuseppe Persiano. Public key encryption with keyword search. In Advances in Cryptology---EUROCRYPT 2004, pages 506--22, 2004.
|
| |
11
|
Dan Boneh, Eyal Kushilevitz, Rafail Ostrovsky, and W. Skeith. Public key encryption that allows PIR queries. In Advances in Cryptology---CRYPTO 2007, pages 50--67, 2007.
|
| |
12
|
|
| |
13
|
|
| |
14
|
Xavier Boyen and Brent Waters. Anonymous hierarchical identity-based encryption (without random oracles). In Advances in Cryptology---CRYPTO 2006, pages 290--307, 2006.
|
| |
15
|
Victor Boyko, Philip MacKenzie, and Sarvar Patel. Provably secure password-authenticated key exchange using Diffie-Hellman. In Advances in Cryptology---EUROCRYPT 2000, 2000.
|
| |
16
|
|
| |
17
|
Christian Cachin, Silvio Micali, and Michael Stadler. Computationally private information retrieval with polylogarithmic communication. In Advances in Cryptology---EUROCRYPT 1999, pages 402--14, 1999.
|
| |
18
|
|
| |
19
|
Ran Canetti, Shai Halevi, Jonathan Katz, Yehuda Lindell, and Philip MacKenzie. Universally composable password-based key exchange. In Advances in Cryptology---EUROCRYPT 2005, pages 404--21, 2005.
|
| |
20
|
|
| |
21
|
David Chaum. Blind signatures for untraceable payments. In Advances in Cryptology---CRYPTO 1982, pages 199--203, 1982.
|
| |
22
|
|
| |
23
|
Yevgeniy Dodis and Adam Smith. Entropic security and the encryption of high-entropy messages. In Theory of Cryptography Conference---TCC 2005, 2005.
|
| |
24
|
Shimon Even, Oded Goldreich, and Abraham Lempel. A randomized protocol for signing contracts. In Advances in Cryptology---CRYPTO 1982, pages 205--10, 1982.
|
| |
25
|
|
| |
26
|
|
| |
27
|
Steven Galbraith, Kenneth Paterson, and Nigel Smart. Pairings for cryptographers. Cryptology ePrint Archive, Report 2006/165, 2006.
|
 |
28
|
|
| |
29
|
Craig Gentry, Philip MacKenzie, and Zulfikar Ramzan. A method for making password-based key exchange resilient to server compromise. In Advances in Cryptology---CRYPTO 2006, LNCS, pages 142--59. Springer-Verlag, 2006.
|
 |
30
|
|
| |
31
|
Matthew Green and Susan Hohenberger. Blind identity-based encryption and simulatable oblivious transfer. In Advances in Cryptology---ASIACRYPT 2007, 2007.
|
| |
32
|
Shai Halevi and Yael Tauman Kalai. Smooth projective hashing and two-message oblivious transfer. Cryptology ePrint Archive, Report 2007/118, 2007.
|
 |
33
|
|
| |
34
|
D. N. Hoover and B. N. Kausik. Software smart cards via cryptographic camouflage. In IEEE Symposium on Security and Privacy---SP 1999, 1999.
|
| |
35
|
Jonathan Katz and Rafail Ostrovsky. Round-optimal secure two-party computation. In Advances in Cryptology---CRYPTO 2004, pages 335--54, 2004.
|
| |
36
|
|
 |
37
|
|
| |
38
|
|
| |
39
|
Helger Lipmaa. An oblivious transfer protocol with log-squared communication. Cryptology ePrint Archive, Report 2004/063, 2004.
|
| |
40
|
|
| |
41
|
|
| |
42
|
Andreas Pashalidis. http://www.kyps.net, 2007.
|
| |
43
|
Andreas Pashalidis and Chris J. Mitchell. Impostor: a single sign-on system for use from untrusted devices. In Proc. IEEE Globecom 2004, 2004.
|
| |
44
|
Michael Rabin. How to exchange secrets by oblivious transfer. Technical Report TR-81, Harvard University, Aiken Computation Laboratory, 1981.
|
| |
45
|
|
| |
46
|
|
|