D. C. Feldmeier and P. R. Karn. UNIX Password Security - Ten Years Later. In Proceedings of the Crypto Conference, pages 44--63, August 1990.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....This property states that the function must be collision free, in the sense that no two values of must result in the same belonging to Assuming that the set is sufficiently large, an exhaustive search will be computationally infeasible and thereby impractical. The UNIX password protection scheme [10, 5] is an example of a security mechanism making use of one way functions. It provides confidentiality of the users passwords, thus preventing disclosure of the passwords even though the password file itself is disclosed. By calculating a one way hash (using the DESencryption scheme) of a user s ....

D.C. Fieldmeier and P.R. Karn. UNIX password security - ten years later. Advances in Cryptology CRYPTO 89, LNCS 0302-9743; 435 pp:44-63, Springer cop., 1990.

....space of random passwords could be searched quickly. Klein conducted a wide reaching study of password security in 1989 and notes that 25 of all passwords can be broken with a small dictionary [Kle90] Other notable efforts to design password crackers were conducted by Feldmeier and Karn [FK89] and Muffett [Muf92] Because of these password cracker programs, users need to create unpredictable passwords, which are more difficult to memorize. As a result, users often write their passwords down and hide them close to their work space. Strict password policies, such as forcing users to ....

....discussed in section 4. The majority of solutions to the problems of weak passwords fall into three main categories. The first types of solutions are proactive security measures that aim to identify weak passwords before they are broken by constantly running a password cracking programs [MT79, FK89] The second type of solution is also technical in nature, which utilizes techniques to increase the computational overhead of cracking passwords [Man96] The third class of solutions involves user training and education to raise security awareness and establishing security guidelines and rules ....

D. C. Feldmeier and P. R. Karn. UNIX password security---ten years later (invited), 1989. Lecture Notes in Computer Science Volume 435.

....resistant to remote capture. Biometrics, however, pose a security risk that passwords do not. In many operating systems, as in most implementations of UNIX, a given password P is not stored explicitly in the system password le. Instead, a commitment of P is stored in the form of a hash h(P ) [18, 26]. 1 (Note that this hash may be regarded as a commitment on a null value for which P is the witness. Thus it is possible to verify that a user has entered her password correctly, while even a system administrator cannot feasibly extract a well chosen password P from the password le entry h(P ....

D.C. Feldmeier and P.R. Karn. UNIX password security { ten years later. In G. Brassard, editor, Advances in Cryptology - CRYPTO '89, pages 44-63. SpringerVerlag, 1989. LNCS No. 435.

....(PDA s) storage from probes by an attacker. In contrast, repeatability is achieved in our schemes, thereby enabling designs in which the device, if captured, is of little help to the attacker (see Section 1) The security of textual passwords has been examined by numerous researchers, notably [MT79, Kle90, FK90, Spa92, Wu99]. Without exception, these studies reiterate the fact that people choose passwords that are easy to find by automated search. In order to improve the security of passwords, it is common practice for system administrators to invoke reactive password checkers to identify weak passwords [RU88, ....

D. Feldmeier and P. Karn. UNIX password security -- Ten years later. In Advances in Cryptology--- CRYPTO '89 Proceedings (Lecture Notes in Computer Science 435), 1990.

....A fast encryption algorithm based on the SAFERK64 algorithm [11] has been chosen because the processing time spent in the more complex DES encryption algorithm can hide total ly the ILP performance gain [4] Even a high speed implementation achieves only a 1. 22 Mbps throughput on a SUN 4 280 [12]. SAFERK64 is extremely fast compared to other standard algorithms such as DES (25 Mbps for SAFERK64 with 1 round compared to 0.5 Mbps for the system implementation of DES on a SPARCstation 10 with a 30 MHz clock) is still too time consum ing for the ILP experiment. The encryption algorithm has ....

Feldmeier, D.C; Karn, P.R.: UNIX Password Security - Ten Years Later, in: Advances in Cryptology - CRYPTO '89, Lecture Notes in Computer Science 435, Springer-Verlag, 1990, pp.44-53 23

....header. A fast encryption algorithm based on the SAFERK64 algorithm [9] has been chosen because the processing time spent in the more complex DES encryption algorithm can hide totally the ILP performance gain [4] Even a high speed implementation achieves only a 1 Mbps throughput on a SPARCstation [10]. SAFERK64 that is extremely fast compared to other standard algorithms such as DES (25 Mbps for SAFERK64 with 1 round compared to 0.5 Mbps for the system implementation of DES on a SPARCstation 10 with a 30 MHz clock) is still too time consuming for the ILP experiment. The encryption algorithm ....

Feldmeier, D.C; Karn, P.R.: UNIX Password Security - Ten Years Later, in: Advances in Cryptology - CRYPTO '89, Lecture Notes in Computer Science 435, Springer-Verlag, 1990, pp.44-53

.... attacks or guessing attacks [9] while all available evidence suggests that forcing people to choose and remember good passwords those that tend to be long character strings including both Roman letters and digits is unworkable because such well chosen passwords are also quite unmemorable [3, 7]. Authentication protocols have been proposed that are resistant to password guessing attacks [8, 6, 1, 2] although they are more expensive in terms of the numbers of messages and rounds than those authentication protocols without the additional requirement to protect weak passwords [4, 5] For ....

D.C. Feldmeier and P.R. Karn. UNIX Password Security - Ten Years Later. In Proceedings of Crypto'89, volume 435 of Lecture Notes in Computer Science, pages 44--63. Springer-Verlag, 1989.

....in the passwordfile for that particular user. If the output corresponds to the eleven bytes that represent the crypted password in the passwordfile the password is considered valid and the user will be permitted to access the system. For more information on the precise working of DES on UNIX see [Fel2]. Schematically it looks like this: 25x DES encryption 64 0 bits Rfuu4.4hY0U (from etc passwd ) result) key) salt) correspondance: password accepted inputted password fu Rfuu4.4hY0U As I just pointed out it is not possible (in real life) to decrypt passwords. However, it is possible to ....

DAVID C. FELDMEIER, PHILIP R. KARN, UNIX Password Security -- Ten Years Later, Proceedings of Advances in Cryptology -- CRYPTO '89, 1989.

....PC or UNIX server at her disposal. We realize that, for instance, specialized hardware for DES encryption has been proposed built, but we suspect that most attackers do not (as yet) have access to these machines. The figure can be calculated in various ways, see for instance Karn and Feldmeir s [6] analysis (naturally the actual numbers in that paper are five years old and are obsolete) an implementation specific constant that captures the amount of effort the attacker must expend per user for a specific system. For instance, in UNIX, an attacker searching through a dictionary of size , ....

Karn, P.R. and D.C. Feldmeier, "UNIX password security - Ten years later", Advance in Cryptology - CRYPTO 89. G. Brassard (Ed.) Lecture Notes in Computer Science, Springer-Verlag. 1990.

....for hundreds of guesses a second When the password scheme for UNIX was first developed, an old encryption scheme was used, but was deemed too risky because encryption took about 1 ms on a PDP11 70. So instead, a scheme based on the DES standard was used. As pointed out by Feldmeier and Karn [FK89], current fast implementations of DES and current fast machines allow encryption to be even faster today than the one rejected 15 years ago. In this short paper, we suggest a simple scheme that should tilt the playing field back to the good guys favor. In will make guessing much more difficult. ....

Feldmeier D. C., and P. R. Karn, "UNIX password security --- ten years later," Proceedings of the UNIX Security Workshop (August 1989).

....value h(p) then it is assumed that p 0 = p. If h(p 0 ) does not match h(p) the attacker tries the next candidate value of p 0 from a list of guesses, perhaps a dictionary that contains all words in the sender s language, plus a list of proper names, rock group names, and cartoon characters [Feldmeier 89, Klein 90] The Internet Worm guessed passwords in the same way [Seeley 89] A possible solution is to restrict access to the file etc passwd. 2.2 SunOS Secure NFS Because of the known risks of the UNIX password system, the SunOS 4.0 documentation recommends that the file etc passwd be removed ....

D.C. Feldmeier and P.R. Karn, "UNIX Password Security - Ten Years Later", Proceedings of Crypto'89, published as Lecture Notes in Computer Science, No.435, Springer-Verlag, pp.44-63.

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D. C. Feldmeier and P. R. Karn. UNIX Password Security - Ten Years Later. In Proceedings of the Crypto Conference, pages 44--63, August 1990.

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D.C. Feldmeier, P.R. Karn, \UNIX Password security { ten years later", Advances in Cryptology { CRYPTO'89, Lecture Notes in Computer Science 435, Springer-Verlag (1990) 44-63.

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D. Feldmeier and P. Karn. UNIX password security---Ten years later. In Advances in Cryptology---CRYPTO '89 (Lecture Notes in Computer Science 435), 1990.

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Feldmeier D, Karn P (1990) UNIX password security -- ten years later. In: Advances in cryptology -- CRYPTO '89, Santa Barbara, August 1989. Lecture notes in computer science, vol 435, Springer, Berlin Heidelberg New York, pp 44--63

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D. C. Feldmeier and P. R. Karn. UNIX Password Security - Ten Years Later. In Proceedings of the Crypto Conference, pages 44--63, August 1990.

No context found.

David C. Feldmeier and Philip R. Karn, "UNIX Password Security - Ten Years Later," CRYPTO Proceedings,Summer 1989.

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