Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Sun, 19 Oct 2014 15:13:14 +0300
From: Milen Rangelov <>
Subject: Re: Re: PKZIP and GPU acceleration


> For this format, GPUs don't matter.  (We do have a GPU-enabled format
> for the newer WinZip/AES archives, but not for the old PKZIP.)

I do not completely agree, but it depends on the number of files in the zip
archive. If you have a single file, then yes - it does not matter. If you
have at least several files, then you get additional verifiers and then you
can do most of the work on the GPUs leaving decryption/decompression/CRC
check on the CPU for just a very small subset of the password candidates. A
zip archive with 4-5 files in it can greatly benefit from GPU processing, I
remember speeds exceeding 1B/s on a 7970. But I also remember being asked a
lot of times why cracking old zip format is much slower than what I've
tweeted a while ago and I have to explain the same thing over and over

On Sat, Oct 18, 2014 at 7:19 PM, Federico <> wrote:

> Greetings from italy
> Right now i'm trying to decrypt a pkzip hash on a c3.8xlarge
> This is a 1.7.9 jumbo with openmp:
> Benchmarking: PKZIP [32/64]... (32xOMP) DONE
> Many salts:     148070K c/s real, 4630K c/s virtual
> Only one salt:  34508K c/s real, 1078K c/s virtual
> At work:
> guesses: 0  time: 0:00:02:32 0.00% (3)  c/s: 28193K  trying: 29vgwbip -
> 29v336s0
> How about this? Sounds good?
> On the official 1.8.0 i cant decrypt pkzip hashes (havent tryed a test
> with fork=32)

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.