phc-discussions - Re: [PHC] Schvrch is broken

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Date: Mon, 15 Sep 2014 12:05:47 -0500 (CDT)
From: Steve Thomas <steve@...tu.com>
To: discussions@...sword-hashing.net
Subject: Re: [PHC] Schvrch is broken

> On September 14, 2014 at 11:06 PM Rade Vuckovac <rade.vuckovac@...il.com>
> wrote:
>
>  Regarding time cost
>
>  As it stays (more details is needed perhaps) the statement about PHC_Fast
>does not pass a basic logic.  Since PHS_Fast function is allegedly time
>constant function it means that the time cost is indifferent factor. In other
>words only input which is varied through the initial search is the password.
>That leads that PHC_Fast function, without even inspecting inner working
>(treating it as a black box) has multiple outputs for the same input???
>

I guess I should of just posted code in my first message:
https://github.com/Sc00bz/break-schvrch

This takes about 3 minutes to run. With SSE or AVX it will be faster but this is
a nice PoC. Note that the generation only needs to be done once per m_cost and
once for each t_cost when m_cost is zero.