Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth

Newsgroups	comp.lang.forth
Date	2012-12-13 20:17 -0800
References	(1 earlier) <50b4c134.156405635@192.168.0.50> <7a6a5bbd-eb18-4618-a868-5d152fad0c4f@googlegroups.com> <7x1ueuano2.fsf@ruckus.brouhaha.com> <8889040f-a006-4dbd-8956-a231b492c068@googlegroups.com> <7xy5h2fist.fsf@ruckus.brouhaha.com>
Message-ID	<626ebdde-0470-48f7-bd2e-d121942b2e67@googlegroups.com> (permalink)
Subject	Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth
From	Howerd <howerdo@yahoo.co.uk>

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On Thursday, December 13, 2012 9:38:42 AM UTC+1, Paul Rubin wrote:
> Howerd <howxxxx@yahoo.co.uk> writes:
> 
> > I am not aware of TEA being particulary slow...
> 
> 
> 
> TEA with the recommended 64 rounds is slower than a carefully optimized
> 
> software implementation AES-128, I believe, plus it has various
> 
> cryptanalytic issues.
> 
> 
> 
> Modern x86's have AES in hardware and maybe we'll start seeing it in
> 
> other processors too.  They've got to do something with all that
> 
> silicon.  SHA3 (Keccak) also looks simple, though less simple than
> 
> CubeHash.

Hi Paul, 

IIRC the number of rounds for the original TEA was 32, which would double the speed. You can adjust the strength by changing the number of rounds to get the right trade-off between strength and speed.
Maybe the 64 rounds recommendation came ater the X-Box fiasco...

For me, it is more important to have an algorithm that is so simple that there are obviously no backdoors, rather than something based on complicated maths.
Also to be avoided is anything involving s-boxes, as these may allow relatively simple parallel calculations to crack the algorithm.

Also with TEA it is very easy to expand to wider bit lengths - you just create primitives for, say 128 bit rotate, shift and add. Logically the longer words must inherit the same security features as the shorter ones, but with more strength.

> it has various cryptanalytic issues. 
Yes, there were some issues to do with the original TEA to do with equivalent keys reducing the key space to 126 bits. Also the key mixing was not quite right. I think that these were both solved with TEAN, which is now called XTEA.

Its a complex subject...

Best regards,
Howerd

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Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth stephenXXX@mpeforth.com (Stephen Pelc) - 2012-11-27 13:36 +0000
  Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-11-28 14:31 -0800
    Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-11-28 14:36 -0800
    Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Josh Grams <josh@qualdan.com> - 2012-11-30 00:08 +0000
      Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-11-30 13:56 -0800
        Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Josh Grams <josh@qualdan.com> - 2012-12-01 16:02 +0000
          Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-12-01 13:54 -0800
            Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Josh Grams <josh@qualdan.com> - 2012-12-02 11:26 +0000
    Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-12 14:52 -0800
      Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-12-12 23:47 -0800
        Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-13 00:38 -0800
          Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-12-13 20:17 -0800
            Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-13 20:25 -0800
              Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-12-13 20:53 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-13 21:16 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-12-14 03:43 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-14 12:15 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-20 00:21 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-14 04:45 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Howerd <howerdo@yahoo.co.uk> - 2012-12-14 03:33 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-14 12:20 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-14 10:28 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-14 12:39 -0600
              Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-15 01:47 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-19 18:10 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-19 19:53 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-20 14:44 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-20 19:28 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-20 13:56 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-21 01:41 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-21 03:58 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-21 02:20 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-21 06:46 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-21 15:34 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-21 08:40 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-22 03:36 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-21 20:07 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-23 02:37 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-22 19:24 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-23 15:52 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-23 17:52 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-24 03:57 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-24 16:20 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-24 15:36 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-25 02:52 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-24 21:51 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-25 20:56 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Paul Rubin <no.email@nospam.invalid> - 2012-12-26 01:08 -0800
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-26 16:02 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth David Thompson <dave.thompson2@verizon.net> - 2012-12-31 02:48 -0500
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth kenney@cix.compulink.co.uk - 2012-12-24 03:20 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-22 03:24 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-23 01:24 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-23 04:59 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-23 17:32 +0100
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-12-23 11:28 -0600
                Re: ANN: SHA-256 Secure Hash Algorithm in ANS Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-12-24 00:30 +0100

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