phc-discussions - Re: [PHC] Let's not degenerate when if the PRF is too narrow for desired output

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <877gk1v77w.fsf@latte.josefsson.org>
Date: Wed, 17 Apr 2013 11:26:11 +0200
From: Simon Josefsson <simon@...efsson.org>
To: Jeffrey Goldberg <jeffrey@...dmark.org>
Cc: "discussions\@password-hashing.net" <discussions@...sword-hashing.net>
Subject: Re: [PHC] Let's not degenerate when if the PRF is too narrow for desired output

Jeffrey Goldberg <jeffrey@...dmark.org> writes:

> This is mostly me whining. I just got bitten by the fact that PBKDF2
> does weird stuff if you ask for more derived data than is natural for
> the PRF you give it.

Perhaps this can be converted into a requirement for a nicer KDF: the
cost to compute one bit of the output should be as high as computing the
entire output?

/Simon