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Re: CHAL2X

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On 26.09.21 22:19, Stefan Claas wrote:
> On Sunday, September 26, 2021 at 9:57:12 PM UTC+2, Richard Heathfield wrote:
>> On 26/09/2021 20:41, Ben Bacarisse wrote:
>>> Max <maxt...@gmx.net> writes:
>>>
>>>> One more question: the seed has to be an integer, right? What is the
>>>> valid range for it? At some stage I will take a closer look at the
>>>> code, but for now asking you is the lazy option for me. Hope you don't
>>>> mind.
>>>
>>> The codes says:
>>>
>>> * TODO: validate the sbseed to ensure it's < 2^31.
>> Indeed. In actual use it won't last more than a few microseconds before
>> it's &='d with 0x7FFFFFFFUL.
> 
> I have a little question (I am no C programmer) Do you think it would make
> sense that instead of typing in the sbseed value it would be useful if a user
> of your software would run something like:
> 
> shuf -i 1-2147483647 -n 100 > sbseed.txt
> 
> and your program would mark the used values, after usage, with
> say an '*', so than when all values are used your program would
> say something like 'sbeed file used up'?
> 
> Regards
> Stefan
> 

Hey, Stefan, you bring up a valid point. If the seed is crucial to the 
security of the cipher, 2**31 gives you collisions after about 2**16, 
i.e. 65k, messages. That's not a lot. Alternatively, could the PRNG be 
enhanced to also work with, say, 96 bit-seeds?

Cheers,

Max

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Thread

CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-23 16:34 +0100
  Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-25 19:45 +0200
    Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-25 19:04 +0100
      Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-25 20:08 +0200
  Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-25 23:03 +0200
    Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-25 22:14 +0100
      Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 00:53 +0200
        Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 06:59 +0100
          Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 14:40 +0200
            Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 13:58 +0100
              Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 15:54 +0200
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 15:06 +0100
                Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 17:11 +0200
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 16:53 +0100
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 17:12 +0100
                Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 18:42 +0200
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 18:27 +0100
                Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 20:43 +0200
                Re: CHAL2X Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-09-26 20:41 +0100
                Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 21:46 +0200
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 20:57 +0100
                Re: CHAL2X Stefan Claas <spam.trap.usenet@gmail.com> - 2021-09-26 13:19 -0700
                Re: CHAL2X Max <maxturv26@gmx.net> - 2021-09-26 22:30 +0200
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 21:37 +0100
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 21:33 +0100
                Re: CHAL2X Stefan Claas <spam.trap.usenet@gmail.com> - 2021-09-26 13:39 -0700
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-26 20:53 +0100
                Re: CHAL2X Colin <a@b.com> - 2021-09-27 19:11 +1300
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-27 07:41 +0100
                Re: CHAL2X Colin <a@b.com> - 2021-09-27 20:02 +1300
                Re: CHAL2X Richard Heathfield <rjh@cpax.org.uk> - 2021-09-27 08:27 +0100
                Re: CHAL2X Colin <a@b.com> - 2021-09-28 20:09 +1300

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