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Date: Thu, 15 Nov 2012 20:17:29 +0100
From: magnum <>
Subject: NT vs NT2 explained (was: LM with empty strings = password longer than 15 chars?)

On 15 Nov, 2012, at 14:06 , Rich Rumble <> wrote:
> Yep, even without knowing the specifics of the LM settings, the blank
> hash in the LM spot mean use NT or NT2 (is one faster than the other?
> I've never been clear on that...) They are both the same format, so
> I'm not sure why there are 2 implementations of it.

The NT2 format (it would have been called NT-ng with our later "name standard") was originally written just for benchmarking Simon's MD4 SSE2 intrinsics code, as compared to Alain's SSE2 assembler used in the NT format. We kept NT2 in the tree because on some systems it outperforms the NT format. On other systems, the NT format wins. Sometimes the difference is negligible, sometimes it's significant. So like someone said, just use what is fastest on the system you are using. There are no other differences: Both have a max. length of 27 characters (because that is the maximum that will fit in one block of MD4) and both now support codepages, UTF-8 and whatnot.

The performance of the NT format only depends on your hardware. The NT2 format does too but it is also *highly* dependant on the compiler's ability to schedule instructions optimally.


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