Challenges from competitors

[Madness]

Bellaso’s lost cipher:

Before the “Porta” cipher was stolen from him, Giovan Battista Bellaso invented a better (but similar) cipher.
If enough of you want, I can post a description of the cipher and some ciphertexts.

[The-letter-wriggler]

Would it be enough if only one of us want it?

[67105112104101114]

I’m interested

[Madness]

@TLW, let’s see who responds in the next few days. If it’s just you, I’ll send you the PDF.
Meanwhile, I still have those plaintexts you asked me to hold.

[Fevans]

I’m interested!

[Cribbage]

Count me in!
It’s good to see some familiar names again – I hope you are all doing well.

[The-letter-wriggler]

@Madness, good idea, would like for more people to get involved too.
You can send me them texts anytime. TIA.

[Bubble_sort]

I’d be down to have a crack at them as well.

[The-letter-wriggler]

Just in case any one missed out on the 2020 S.E. ELITE cipher…
Maybe you did not find it or you would like to know the solution
and how to decrypt it – fear not you can find it here

Elite

don’t miss the wonderful write-up by the first person to solve it, Madness.

(Harry I do not see this write-up in the resources as stated there)

[Jbrintcrypt]

A little puzzle that I came up with and wanted to see if it works…
… this puzzle is in the form of concealed text and isn’t intended to be very difficult. You should end up with a five letter word (Clue: association with a fictional detective). You’ll know once you’ve got the answer, unless I haven’t double checked it well enough.

i am InTerested In LearnIng To fInd, LogIcaLly, if ThIs conceaLed texT Is Truly invIsibLe If I hIde It so.
iT TruLy Took aT leasT tweLve mInuTes In Lining up The IndivIdual words.
i wIsh, Therefore, to see If a LoT of atTempTs couLd be Issued To solve It.
ThIs lasT senTence shouLd InsTantLy indIcaTe i am wrIting the Longest word, i ThInk its Length Is ITs cLear indIcation thIs word Is Longer.

[Cribbage]

Thanks, Madness. I am not sure my method was the most efficient as there was one part where my calculation of the shift seemed to involve too much modular division. I need to check the rules for simplifying expressions with modular arithmetic.

[Have deleted the answers here, sorry. Could I suggest posting encrypted solutions to Madness so others can still have a go? Harry]

[Harry]

Thanks TLW, you are right, Madness’s solution has gone AWOL during a page reorganisation. Will have to hunt it down and post again. Might be worth a page of its own so I can show the original. Apologies for the lacuna matata, it’s not a wonderful thing.

Harry

[Cribbage]

As suggested, here is a response for Madness, using Bellaso’s lost cipher but encoded with a key that is different from any of the ones that Madness employed:

GTAOD DASYF PYIOK BMRKY ZGCDF WMZUA OMNUY OSMSC XVKJE
HJBUD VGGFU XVIWN RRBMT GKLOZ DYKPN PXGFQ VBUNR JFFBY
FMGFU LXNFR PHRCJ BHGHL XAZZR XUKSE PABHD DJEWC RIIJB
BCRBL ZJDTB KVZJM AXEIK VAIUB HEKKF OWRXU OKLMT EZAKA
NNRVD DJJSL MMJJU NNRHY XTZVN VHFQP BVBZT DAITB PTQAE
HJUMR GSGMQ XBJTT TDUID DJOFU OKRSK BLGIH VCCFG OVAEP
KHGFU FFOEG EVJAC SHQFQ MIRTG RIWGS LTOID MJGHV DGOTN
PJRVP USGFV EZJJU NIGMO CAHMB JULQA XNRTX GULVN LIFZA
PVBAM MFEOG OJROS BLUMM WSMOG SUAKW XOGFP QILDF JMKOA
GJGTL IUGQX JFNGE OABZU CJSRR NSGYJ NNGFU ZURHV IEFUE
HQROL FMCZY XUFPG SMGCY ZWCDV MMJPT PLLTX KSLFJ XUETO
DIEVU IS!

[Madness]

Here’s how to prove that you have solved something:

Take your plaintext and express it in all caps with no spaces or punctuation, like this:
THISISTHEPLAINTEXT

Add your username, also in all caps and without spaces:
THISISTHEPLAINTEXTMADNESS

Find the MD5 hash of the result, without a trailing newline.

On Mac:
echo -n THISISTHEPLAINTEXTMADNESS | md5

On linux:
echo -n THISISTHEPLAINTEXTMADNESS | md5sum

On Windows:
Download an MD5 utility, such as the one at http://www.fourmilab.ch/md5
Then,
md5 -dTHISISTHEPLAINTEXTMADNESS
(no space between -d and the answer)

With the above example, I get bb50cc93aec9b37a42ea3538b99a4ffc on linux and windows. You can
use the example to test that you know what you are doing.

Here’s why we should do it this way: MD5 is a one-way function; i.e., it is very easy to calculate
an MD5 hash of some data, but very, very, very, very, very, very, very, very, very, very, very, very,
very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very,
very, very, very, very, …I’m almost finished… very, very hard to reconstruct the data from
the MD5 hash. Adding your username means that your hash will be different from someone else’s, so
no one can steal your answer and claim to have the answer.

[The-letter-wriggler]

Harry you said ‘Apologies for the lacuna matata, it’s not a wonderful thing.’

I thought you had slipped on the l and that you meant h.

If you really knew what lacuna meant then I salute you.

A little research…

…The second word is lacuna, and actually refers more to a missing portion of
a written work. It also had the Latin grapheme in its plural form, but at the
end. It came to English in the 1660s, and the Latin word refers to a hole or
a pit (obviously into which letters, words, or sections of manuscripts can
disappear.)

Hakuna Matata, is a Swahili phrase meaning “no problem”. Its literal
translation is “there are no worries.”

So now I know 🙂

[Author]

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