25,188 research outputs found
Robust and efficient password authenticated key agreement with user anonymity for session initiation protocol-based communications
A suitable key agreement protocol plays an essential role in protecting the communications over open channels among users using Voice over Internet Protocol (VoIP). This paper presents a robust and flexible password authenticated key agreement protocol with user anonymity for Session Initiation Protocol (SIP) used by VoIP communications. Security analysis demonstrates that our protocol enjoys many unique properties, such as user anonymity, no password table, session key agreement, mutual authentication, password updating freely and conveniently revoking lost smartcards etc. Furthermore, our protocol can resist the replay attack, the impersonation attack, the stolen-verifier attack, the man-in-middle attack, the Denning-Sacco attack, and the offline dictionary attack with or without smartcards. Finally, performance analysis shows that our protocol is more suitable for practical application in comparison with other related protocols
Security Analysis of A Dynamic ID-based Remote User Authentication Scheme
Since 1981, when Lamport introduced the remote user authentication scheme using table, a plenty of schemes had been proposed with table and without table using. Recently Das, Saxena and Gulati have proposed A dynamic ID-based remote user authentication scheme. They claimed that their scheme is secure against ID-theft, and can resist the reply attacks, forgery attacks, and insider attacks and so on.
In this paper we show that Das et al.’s scheme is completely insecure and using of this scheme is equivalent to an open server access without any password
Password Cracking and Countermeasures in Computer Security: A Survey
With the rapid development of internet technologies, social networks, and
other related areas, user authentication becomes more and more important to
protect the data of the users. Password authentication is one of the widely
used methods to achieve authentication for legal users and defense against
intruders. There have been many password cracking methods developed during the
past years, and people have been designing the countermeasures against password
cracking all the time. However, we find that the survey work on the password
cracking research has not been done very much. This paper is mainly to give a
brief review of the password cracking methods, import technologies of password
cracking, and the countermeasures against password cracking that are usually
designed at two stages including the password design stage (e.g. user
education, dynamic password, use of tokens, computer generations) and after the
design (e.g. reactive password checking, proactive password checking, password
encryption, access control). The main objective of this work is offering the
abecedarian IT security professionals and the common audiences with some
knowledge about the computer security and password cracking, and promoting the
development of this area.Comment: add copyright to the tables to the original authors, add
acknowledgement to helpe
PALPAS - PAsswordLess PAssword Synchronization
Tools that synchronize passwords over several user devices typically store
the encrypted passwords in a central online database. For encryption, a
low-entropy, password-based key is used. Such a database may be subject to
unauthorized access which can lead to the disclosure of all passwords by an
offline brute-force attack. In this paper, we present PALPAS, a secure and
user-friendly tool that synchronizes passwords between user devices without
storing information about them centrally. The idea of PALPAS is to generate a
password from a high entropy secret shared by all devices and a random salt
value for each service. Only the salt values are stored on a server but not the
secret. The salt enables the user devices to generate the same password but is
statistically independent of the password. In order for PALPAS to generate
passwords according to different password policies, we also present a mechanism
that automatically retrieves and processes the password requirements of
services. PALPAS users need to only memorize a single password and the setup of
PALPAS on a further device demands only a one-time transfer of few static data.Comment: An extended abstract of this work appears in the proceedings of ARES
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