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Challenge "A Cloaked Substitution Cipher — Part 2"

Challenge "A Cloaked Substitution Cipher — Part 2"  

  By: admin on Aug. 25, 2019, 7:26 p.m.

Like the MONOALPHABETIC SUBSTITUTION WITH CAMOUFLAGE series of challenges, this two-part challenge considers a modification of the classic simple substitution cipher achieved by randomly introducing decoy characters into the ciphertext in encryption which are then ignored in decryption. In part 2, the plaintext is first divided into two parts, then each part will be encrypted separately.
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Re: Challenge  

  By: D3d4lu5 on Aug. 25, 2019, 10:21 p.m.

The kind of solution should be changed.

It's really annoying to spend most of your time finding the right punctuation.

Re: Challenge  

  By: Veselovský on Aug. 25, 2019, 11:39 p.m.

Well, after seeing A CLOAKED SUBSTITUTION CIPHER – PART 1 I wondered what might be the next part? It was just first part so I expected (if not first part) next parts will bring something new…

And to be true I did not expect what I see - I am surprised. Another copy of one challenge of Camouflage series.

A least the name is something that is new, but there are many synonyms for camouflage.

A tip for another series - for example "A Disguised Substitution Cipher" or maybe "A Masked Substitution Cipher", the cipher can stay the same as in Camouflage series. If nothing new, we can add Identity function at the end of encryption process - to camouflage the cipher itself.

Re: Challenge  

  By: curmudgeon on Aug. 26, 2019, 7:37 a.m.

D3d4lu5 has pointed out an error in the description of the challenge. On page 10/12 the parenthetical remark:

(where sentences are defined as character strings ending in either a period or a question mark followed by a space, and hyphenated words are counted as single words)

should be amended to read:

(where sentences are defined as character strings ending in either a period or a question mark, and hyphenated words are counted as single words)

(The original wording unintentionally excluded the final sentence of the solution, which ends with a character not followed by a space.)

Re: Challenge  

  By: Veselovský on Aug. 26, 2019, 11:54 a.m.

After this second part of the challenge being published and also reading this article http://eprint.iacr.org/2019/621.pdf by the same author I had to reconsider my attitude to the matter.

I want to stress out two things:

  1. One thing is not realizing that some two encryption procedures might be commutative - not realizing for whatever reason (mistake, ignorance or neglecting). And then "inventing" cipher that its principal differences from original cipher reduce to less than cosmetic differences. We are humans prone to making mistakes. It is OK and it has nothing to do with morality.

  2. But the other thing is amending some cipher (either with reasonable or irrelevant amendments), coining a new name for it and then presenting it as something new without mentioning sources of original cipher. It is called plagiarism - the practice of taking someone else's work or ideas and passing them off as one's own. An this is morally low.

It is evident that the author copied my ideas and work from Camouflage series here on Mystery Twister site and then presented it on Cryptology ePrint Archive (http://eprint.iacr.org) as his own work without even trying to add something new to it - and what is worse - without mentioning sources.

Cryptology ePrint Archive: Report 2019/621
A Modified Simple Substitution Cipher With Unbounded Unicity Distance

Bruce Kallick

Abstract: The classic simple substitution cipher is modified by randomly inserting key-defined noise characters into the ciphertext in encryption which are ignored in decryption. Interestingly, this yields a finite-key cipher system with unbounded unicity.

Category / Keywords: secret-key cryptography / finite-key, unicity, randomization

Date: received 1 Jun 2019

Contact author: curmudgeon at rudegnu com

Available format(s): PDF | BibTeX Citation

Version: 20190603:070928 (All versions of this report)

Short URL: ia.cr/2019/621

My Camouflage challenges were published since 2011. The author (curmudgeon) of Cloaked cipher is member of Mystery Twister from Jan 13, 2014 so it is evident that he was aware of Camouflage cipher and copied it in his article published on 1 Jun 2019 on Cryptology ePrint Archive.
I am not very happy with that.

Re: Challenge  

  By: admin on Aug. 26, 2019, 5:46 p.m.

It's really annoying to spend most of your time finding the right punctuation.

Would it be ok for you that we delete "followed by a space" on page 10? If not please send me a private message with your suggestion.

Re: Challenge  

  By: Veselovský on Aug. 31, 2019, 11:38 a.m.

Those numbered questions are addressed to whoever who wants to verify my assertion that Cloaked cipher is an exact copy of Camouflage cipher.

(Compared are Camouflage part 3 and Cloaked part 2 ciphers/challenges)

  1. Do you recognize that S(T(m))=T(S(m))=c? (where S stands for monoalphabetic substitution and T for transposition) In words - that S/T and T/S are identical ciphers? This is called a commutative property.

  2. Do you recognize that Camouflage cipher consists of two procedures - monoalphabetic substitution and random interleaving of two strings?

  3. Do you recognize that random interleaving of two strings is a special case of transposition?

  4. Do you recognize that Camouflage cipher is therefore a variant of S/T cipher?

  5. Do you recognize that Cloaked cipher uses the exact same procedures as Camouflage cipher just in swapped order?

  6. Do you recognize that therefore Cloaked cipher is an exact copy of original Camouflage cipher? [/list:u]

Purported differences between Camouflage cipher and Cloaked cipher that are irrelevant regarding cipher type (with explanations):

a. The alphabets are different. It is not the alphabet that makes the cipher in this case. Monoalphabetic substitution remains the same cipher whether used with alphabet of length 26 or 31. The Camouflage cipher can be used with any alphabet. Different alphabets of different lengths were used in each part of the Camouflage series.

b. The keys are different. This is not true. The formats in which the keys are written are different but the keys are identical. Do you recognize that the concatenation of keys K1 and K2 used in Cloaked cipher is identical to key K that could be used in Camouflage cipher? I.e. K=K1<>K2. [/list:u]

I solved both Cloaked challenges and I used the same program I created in 2011 without modifications and I did not even look at the python code, because firstly I do not use python and secondly because I knew I did not have to since I immediately recognized the ciphers were identical.

And last question: Why the article published on ePrint Archive should not be considered as a plagiarism?

My final conclusion: To name things with their real names - Appropriate title for the article should be "Description of a cipher the author saw on Mystery Twister." Nothing more nothing less, it is merely a description of Camouflage cipher.

Re: Challenge  

  By: Bart13 on Sept. 3, 2019, 8:34 a.m.

I couldn't agree more with Viktor: same program that I used to solve his Camouflage challenges worked without modifications for the Cloaked Substitution Cipher.

Why is the author of this challenge not responding to the questions asked?

Re: Challenge  

  By: curmudgeon on Sept. 4, 2019, 1:37 p.m.

Bart13 asks:

Why is the author of this challenge not responding to the questions asked?

I replied to Veselovský on Aug 24, 2019 in the "A Cloaked Substitution Cipher — Part 1" topic:

I will reply to your questions and then say no more on this subject.

I sensed that he, for whaatever reason, seems to bear some animosity toward me (first shown in several posts on February 22, 2019 about the Weakened Handycipher Parts 1 and 2 challenges) and decided not to dignify his mischief-making with any further responses.

But now he writes:

After this second part of the challenge being published and also reading this article http://eprint.iacr.org/2019/621.pdf by the same author I had to reconsider my attitude to the matter.

I want to stress out two things:

  1. One thing is not realizing that some two encryption procedures might be commutative - not realizing for whatever reason (mistake, ignorance or neglecting). And then "inventing" cipher that its principal differences from original cipher reduce to less than cosmetic differences. We are humans prone to making mistakes. It is OK and it has nothing to do with morality.

  2. But the other thing is amending some cipher (either with reasonable or irrelevant amendments), coining a new name for it and then presenting it as something new without mentioning sources of original cipher. It is called plagiarism - the practice of taking someone else's work or ideas and passing them off as one's own. An this is morally low.

It is evident that the author copied my ideas and work from Camouflage series here on Mystery Twister site and then presented it on Cryptology ePrint Archive (http://eprint.iacr.org) as his own work without even trying to add something new to it - and what is worse - without mentioning sources.

My Camouflage challenges were published since 2011. The author (curmudgeon) of Cloaked cipher is member of Mystery Twister from Jan 13, 2014 so it is evident that he was aware of Camouflage cipher and copied it in his article published on 1 Jun 2019 on Cryptology ePrint Archive.
I am not very happy with that.

and then goes on to write:

And last question:
Why the article published on ePrint Archive should not be considered as a plagiarism?

Clearly such a scurrilous attack on my integrity needs to be answered.

To begin with, the idea of inserting decoy characters into a ciphertext did not originate with Viktor Veselovský and can be found in the early history of cryptology. Moreover, it's been an essential element of the Handycipher encryption algorithm from the beginning of its development. See https://eprint.iacr.org/2014/257.pdf and in particular Section 5: Complementary Keys, where the idea of splitting a plaintext into two parts and encrypting them with complementary keys is introduced.

In Section 6: Deniable Encryption, that idea is used to generate a ciphertext that will be decrypted to any two different chosen plaintexts using two complementaary keys. This led to my simplifying the idea by using a simple substitution cipher in place of the Handycipher core cipher and writing the paper "A Modified Simple Substitution Cipher With Unbounded Unicity Distance" https://eprint.iacr.org/2019/621.pdf which Veselovský now insists was taking his work and ideas and passing them off as my own.

In fact I had no knowledge of the MTC3 Camouflage challenges until many months after writing the Unbounded Unicity paper. Thinking that it could form the basis of a worthwhile MTC3 challenge, I proceded to write it up but before submitting it noticed that the cipher I described was essentially the same as that used in the Camouflage challenges. In writing the challenge description I was careful to point this out, linking to the Camouflage challenges and stating that the two ciphers were similar in all essential ways and only differed in a few non-essential ways that I enumeraated.

Re: Challenge  

  By: Veselovský on Sept. 4, 2019, 11:27 p.m.

I sensed that he, for whaatever reason, seems to bear some animosity toward me (first shown in several posts on February 22, 2019 about the Weakened Handycipher Parts 1 and 2 challenges) and decided not to dignify his mischief-making with any further responses.

What is wrong with my comments here?
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They are relevant and to the topic. They commented the required solution not the challenges, cipher or its author.

To begin with, the idea of inserting decoy characters into a ciphertext did not originate with Viktor Veselovský and can be found in the early history of cryptology.

This is true if you are talking about Camouflage part2 or Cloaked part 1 challenges. But you missed the fact that in Camouflage part 3 or Cloaked part 2 there are no decoy characters at all. This is exactly the idea you took from me - random interleaving of two strings (plaintexts or ciphertexts) such that characters in each string preserve their order. Where is the information in your challenges or in your article that you were amending my cipher and what ideas you took from it? Nowhere. Even worse there are missing references to my work.
And one remark - if the cipher was just an idea copied form early history - Why you bothered to publish an article about it? But you are presenting it like something new. You are contradicting yourself - you are implying the cipher is just an old idea here in the forum and at the same time you are presenting it as something new in your article.

See https://eprint.iacr.org/2014/257.pdf and in particular Section 5: Complementary Keys, where the idea of splitting a plaintext into two parts and encrypting them with complementary keys is introduced.

This is still published 3 years after Camouflage series were published and also you were already using account on Mystery Twister in that time.

In fact I had no knowledge of the MTC3 Camouflage challenges

Stop using excuses like high school students do. You are not in the position like - "Prove me that I looked at it". It is a matter of fact that you saw Camouflage challenges - you are a user of Mystery Twister for 6 years. Camouflage challenges are there for 8 years.

Even if you were not member of Mystery Twister, there is still responsibility half on Mystery Twister and half on the author to not publish plagiarisms.

And I say it openly - Bruce Kallick, you are author of plagiarisms - both your challenges and your article are plagiarisms in their current form.

it noticed that the cipher I described was essentially the same as that used in the Camouflage challenges

Why using such vague terms like "essentially"? The proper word is "identical". Like 3+4 is identical to 4+3. And this is exactly what you did with my cipher - you swapped order of two commutative procedures.

Re: Challenge  

  By: admin on Sept. 5, 2019, 1:09 a.m.

We heard the arguments from both sides and see they agree to disagree. The MTC3 team cannot and doesn't want to make decisions about contents of ePrint papers. But we want the people to keep on discussing fairly and respectful here. If there are no really new arguments, please let's stop this discussion here from now on.

Re: Challenge  

  By: madness on Feb. 19, 2020, 5:02 p.m.

Any chance someone who has finished can help me to find the right solution? I have the plaintext, and what I believe to be the correct punctuation, and have tried three possibilities, but all were rejected.

TIA


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