Re: Toy cipher I made for a reddit challenge

From	Max <maxturv26@gmx.net>
Newsgroups	sci.crypt
Subject	Re: Toy cipher I made for a reddit challenge
Date	2021-10-26 20:03 +0200
Organization	Aioe.org NNTP Server
Message-ID	<sl9fsp$1sh0$1@gioia.aioe.org> (permalink)
References	(4 earlier) <sivpc9$av7$1@dont-email.me> <sj03aq$puk$1@dont-email.me> <skheqc$83d$1@dont-email.me> <skhokl$8uq$1@gioia.aioe.org> <2qmdncwGpfKEsOr8nZ2dnUU7-U-dnZ2d@giganews.com>

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On 26.10.21 00:18, Leo wrote:
> Hi all,
> 
>> Leo, as far as I'm concerned I would like to continue this puzzle (and
>> maybe even get to a proper cryptoanalysis later), but without a hint
>> about how the mapping in the babby level is done, I'm definitely stuck.
>>
>> Cheers,
>>
>> Max
> 
> Here is how babbylevel works. The algorithm is essentially a
> substitution cipher, there is a single alphabet. The starting point is
> the unmodified alphabet. For each letter of the key, we grab the
> middle letter of the alphabet and move it to either the beginning, or
> the end.
> 
> I thought this was based on the numerical value of the letter, as in A
> = 0, Z = 25, but apparently I used the index in the current
> substitution table. At this time I do not remember if this is a
> deliberate decision or a typo.
> 
> So when fed each character of the key, the alphabet changes like this.
> 
> Alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ
> Alphabet: ABCDEFGHIJKLMOPQRSTUVWXYZN
> Alphabet: OABCDEFGHIJKLMPQRSTUVWXYZN
> Alphabet: MOABCDEFGHIJKLPQRSTUVWXYZN
> Alphabet: MOABCDEFGHIJKPQRSTUVWXYZNL
> Alphabet: PMOABCDEFGHIJKQRSTUVWXYZNL
> Alphabet: PMOABCDEFGHIJQRSTUVWXYZNLK
> Alphabet: PMOABCDEFGHIJRSTUVWXYZNLKQ
> Alphabet: PMOABCDEFGHIJSTUVWXYZNLKQR
> Alphabet: PMOABCDEFGHIJTUVWXYZNLKQRS
> Alphabet: PMOABCDEFGHIJUVWXYZNLKQRST
> Alphabet: UPMOABCDEFGHIJVWXYZNLKQRST
> Alphabet: UPMOABCDEFGHIVWXYZNLKQRSTJ
> Alphabet: VUPMOABCDEFGHIWXYZNLKQRSTJ
> Alphabet: VUPMOABCDEFGHWXYZNLKQRSTJI
> Alphabet: WVUPMOABCDEFGHXYZNLKQRSTJI
> Alphabet: WVUPMOABCDEFGXYZNLKQRSTJIH
> 
> In the babby level, each key character does one pop and push in the
> alphabet. The plaintext does not affect the alphabet.
> 
> In the further levels, plaintext starts affecting the alphabet as
> well. Also each key starts popping and pushing multiple times.
> 
> CBYZM MSMLI QBCXA CKGYL MUFMW LQBCK QCGMA YYPFR UE
> 

Hi Leo,

thanks for clearing this up. It's humbling to see how I missed such 
basic and kind of organic steps, thinking about much more complex ones.

How do you feel about revealing the whole algorithm and steering the 
discussion more towards its cryptoanalysis?

Cheers,

Max

Thread

Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-09-27 21:15 +0000
  Re: Toy cipher I made for a reddit challenge Richard Heathfield <rjh@cpax.org.uk> - 2021-09-27 23:12 +0100
    Re: Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-09-27 22:32 +0000
    Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-09-28 00:51 +0200
      Re: Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-09-28 04:04 -0500
        Re: Toy cipher I made for a reddit challenge Richard Heathfield <rjh@cpax.org.uk> - 2021-09-28 11:29 +0100
        Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-09-28 21:11 +0200
          Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-09-29 00:00 +0200
            Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-09-30 23:07 +0200
              Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-01 22:29 +0200
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-02 04:20 +0200
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-02 12:18 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-02 13:28 +0200
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-02 16:25 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-02 17:25 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-02 12:28 +0200
                Re: Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-10-02 10:42 -0500
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-02 18:13 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-03 12:27 +0200
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-03 18:02 +0200
                Re: Toy cipher I made for a reddit challenge Stefan Claas <spam.trap.usenet@gmail.com> - 2021-10-03 09:23 -0700
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-03 21:32 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-18 08:52 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-18 19:24 +0200
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-19 00:47 +0200
            Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-17 17:17 +0200
              Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-17 20:05 +0200
                Re: Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-10-25 17:18 -0500
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-26 20:03 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-27 19:49 +0200
                Re: Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-10-27 17:15 -0500
                Re: Toy cipher I made for a reddit challenge Max <maxturv26@gmx.net> - 2021-10-28 12:51 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-28 13:33 +0200
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-10-31 22:17 +0100
                Re: Toy cipher I made for a reddit challenge Richard Heathfield <rjh@cpax.org.uk> - 2021-10-31 22:38 +0000
                Re: Toy cipher I made for a reddit challenge Leo <usenet@gkbrk.com> - 2021-10-31 18:42 -0500
                Re: Toy cipher I made for a reddit challenge "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-10-31 19:30 -0700
                Re: Toy cipher I made for a reddit challenge wizzofozz <oxxxxxxxxxxxs@gmail.com> - 2021-11-01 21:40 +0100

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