[Resource Topic] 2013/525: Catena: A Memory-Consuming Password-Scrambling Framework

Welcome to the resource topic for 2013/525

Title:
Catena: A Memory-Consuming Password-Scrambling Framework

Authors: Christian Forler, Stefan Lucks, Jakob Wenzel

Abstract:

It is a common wisdom that servers should store the one-way hash of their clients’ passwords, rather than storing the password in the clear. In this paper we introduce a set of functional properties a key-derivation function (password scrambler) should have. Unfortunately, none of the existing algorithms satisfies our requirements and therefore, we introduce a novel and provably secure password scrambling framework (PSF) called Catena. Furthermore, we introduce two instantiations of Catena based on a memory-consuming one-way functions. Thus, Catena excellently thwarts massively parallel attacks on cheap memory-constrained hardware, such as recent graphical processing units (GPUs). Additionally, we show that Catena is also a good key-derivation function, since – in the random oracle model – it is indistinguishable from a random function. Furthermore, the memory-access pattern of both instantiations is password-independent and therefore, Catena provides resistance against cache-timing attacks. Moreover, Catena is the first PSF which naturally supports (1) client-independent updates (the server can increase the security parameters and update the password hash without user interaction or knowing the password), (2) an optional server relief protocol (saving the server’s resources at the cost of the client), and (3) a variant Catena-KG for secure key derivation (to securely generate many cryptographic keys of arbitrary lengths such that compromising some keys does not help to break others). We denote a password scrambler as a PSF with a certain instantiation.

ePrint: https://eprint.iacr.org/2013/525

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .