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Re: Researches in quantum computing seem to progress only extremely slowly

From Mok-Kong Shen <mok-kong.shen@t-online.de>
Newsgroups comp.programming
Subject Re: Researches in quantum computing seem to progress only extremely slowly
Date 2015-09-03 00:28 +0200
Organization albasani.net
Message-ID <ms7t6c$sft$1@news.albasani.net> (permalink)
References (5 earlier) <20150902054403.661@kylheku.com> <ms7nf7$j4q$1@news.albasani.net> <c0reua9jbn013grv90b7bpckeq844ljfv6@4ax.com> <ms7ro4$qcm$1@news.albasani.net> <34teuahtcltdi1mrq4gj95bu8gacjv112i@4ax.com>

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Am 03.09.2015 um 00:18 schrieb Robert Wessel:
> On Thu, 3 Sep 2015 00:03:52 +0200, Mok-Kong Shen
> <mok-kong.shen@t-online.de> wrote:
>
>> Am 02.09.2015 um 23:52 schrieb Robert Wessel:
>>> On Wed, 2 Sep 2015 22:50:52 +0200, Mok-Kong Shen
>>> <mok-kong.shen@t-online.de> wrote:
>>>
>>>> Am 02.09.2015 um 15:00 schrieb Kaz Kylheku:
>>>>> On 2015-09-02, Mok-Kong Shen <mok-kong.shen@t-online.de> wrote:
>>>>>> In my code PROVABLEPRIME
>>>>>> (http://s13.zetaboards.com/Crypto/topic/7234475/1/) there is no seed
>>>>>> to be input by the user at all. When the Python session starts, the
>>>>>> system employs the current time to seed its built-in PRNG. So each
>>>>>> time one uses the code to e.g. generate RSA keys, one gets a different
>>>>>> pair by chance. Certainly one could question the security of that from
>>>>>> an "exact" standpoint (I mean in the sense of proofs of pure math),
>>>>>
>>>>> The "exact standpoint" here is quite obvious and it is that a sample of the
>>>>> current time (even if it includes micro or nanoseconds from a high resolution timer,
>>>>> and not only the "seconds sine epoch" or whatever) simply has too few bits of
>>>>> entropy to generate good RSA keys.
>>>>
>>>> I must admit that I yet have doubt on such application of the entropy
>>>> argument (i.e. without regard to how an amount of entropy is actually
>>>> being employed in the processing) due to a paradox that I put up
>>>> and described in a recent another thread: AES-128 in counter mode has
>>>> an input of max 128 bits of entropy but its ouput is commonly used to
>>>> e.g. xor n plaintext bits with n >> 128. The average entropy that is
>>>> contained in one ciphertext bit thus can't be greater than 128/n,
>>>> which is negligible for even moderately large n. Does that imply that
>>>> AES in CTR mode is totally broken?
>>>
>>>
>>> No, it simply means that you don't need to do more than about 2**128
>>> work to break it with a known plaintext attack of sufficient size
>>> (where "sufficient" may be as little as 16 bytes).  But that's not
>>> broken, since that's what we were assuming anyway.  Sure, it's not a
>>> OTP, but it was never meant to be.
>>
>> I don't yet understand. One expands a sequence of 128 bits somehow
>> to a sequence of n bits with n >> 128. If the input 128 bits have
>> a total "entropy" of 128, then it can certainly also be asked how
>> much entropy the output n bits have in total and hence the average
>> value of entropy of each output bit.
>
>
> If there's 128 bits of entropy going in, that's what's coming out.
> Spread over however many bits you output.  IOW, if you encrypt
> something with AES-128 in whatever mode (ignoring any nonce or IV),
> there will be only 2**128 possible decryptions of the message, no
> matter how long it might be.

But you are ignoring the "entropy" in your 2nd sentence. My paradox
is however centered on "entropy". Each input bit is assumed to have
1 bit of entropy. After spreading, the average entropy can't be
larger than 128/n. What is wrong in that calculation logically?
That's what I like very much to know from you or Kylheku.

M. K. Shen


>
> That assumes the key actually has 128 bits of entropy.  If you have a
> poor key generator, the key may well have less than 128 bits of
> entropy, and an attacker may have to check far fewer than 2**128
> possible keys.
>

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Thread

Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-01 13:09 +0200
  Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-01 14:23 +0000
    Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-01 20:00 +0200
      Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-01 18:43 +0000
        Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 10:48 +0200
          Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-02 13:00 +0000
            Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 22:50 +0200
              Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-02 21:31 +0000
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 23:46 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-02 21:58 +0000
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 00:13 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-03 00:32 +0000
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 02:47 +0200
              Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 16:52 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 00:03 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 17:18 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 00:28 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 17:52 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 01:04 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 18:29 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 01:04 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 18:25 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 01:33 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 18:53 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 02:16 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 02:18 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 02:33 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 02:42 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 02:55 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 03:03 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 03:14 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 03:17 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 03:30 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 03:36 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 04:13 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 04:19 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 04:32 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 22:51 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 16:51 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-03 10:49 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-04 19:47 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-04 13:42 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-04 21:50 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-04 20:33 +0000
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-04 23:45 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-05 01:24 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-07 00:50 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-07 14:14 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-07 15:57 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-07 12:19 -0500
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-08 23:47 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-09 02:28 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-04 20:23 +0000
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-05 00:55 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-09-04 17:11 -0700
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-05 02:31 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-09-04 20:15 -0700
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 00:35 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 00:42 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 00:46 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 00:54 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 01:11 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 01:21 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 01:28 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 02:01 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 02:22 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 02:51 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 02:57 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 03:08 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 03:31 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 03:45 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 03:54 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 04:18 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-03 04:24 +0200
                Re: Researches in quantum computing seem to progress only extremely slowly Johannes Bauer <dfnsonfsduifb@gmx.de> - 2015-09-03 07:23 +0200
          Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 16:14 -0500
            Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 23:23 +0200
              Re: Researches in quantum computing seem to progress only extremely slowly Kaz Kylheku <kaz@kylheku.com> - 2015-09-02 21:33 +0000
                Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 23:54 +0200
          Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-02 23:22 +0200
            Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 23:32 +0200
              Re: Researches in quantum computing seem to progress only extremely slowly bartekltg <bartek@gmail.com> - 2015-09-03 00:22 +0200
  Re: Researches in quantum computing seem to progress only extremely slowly "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-09-01 13:23 -0700
    Re: Researches in quantum computing seem to progress only extremely slowly Mok-Kong Shen <mok-kong.shen@t-online.de> - 2015-09-02 11:04 +0200
  Re: Researches in quantum computing seem to progress only extremely slowly Robert Wessel <robertwessel2@yahoo.com> - 2015-09-02 02:22 -0500

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