Challenge #163: Caesar Cipher (on the way to Kryptos)

ROT-13 came into moderate use during the height of Usenet as a way to obscure profanity, dirty talk, movie spoilers, and offensive materials from the casual glance.

The Challenge here is to implement the ROT-13 substitution cipher and apply it TWICE to verify that the ENCODER can be used as its own DECODER!

If you are up for a challenge skip to PART II (which also solves PART I)

challenge_163_start_file.yxmd

Parse

Preparation

Advanced

Data Analysis

Intermediate

Data Preparation

Transform

Accepted answers

NicoleJohnson

LOVED THIS CHALLENGE. (To be fair, I just did my first Escape Room this weekend, so I'm kinda still psyched about the whole solving puzzles thing...)

Spoiler

Decided to solve both parts, and then took a cue from @T_Willins and made an app out of it so that you can code/decode your own messages!

Part I:
Solved without having to hard code a key by utilizing my favorite lesser-known formula, CharToInt and CharFromInt. Able to create a 3 tool solution (Parse > Formula > Summarize) that will allow you to code/decode ROT-13 messages, including the ability to keep upper & lowercase letters in their original case.

Part II:
For Caesar's Cipher, I used Generate Rows to create 26 possible rotations, and then more-or-less used the same solution as above, just substituting the RowCount field from Generate Rows tool for the 13 used in Part I. Solution = some advice that certain members of the kingdom of Westeros would be wise to heed... attack at once!!

Part III:
Created an app out of the solution above... and then had to entirely rework it once I realized that the same value could not be used to decode the message as to encode it if that number wasn't 13. Oops. So I modified both to allow for encoding as well as decoding, which now gives you a handy little Cipher for sending secret messages behind enemy lines!

Cheers!

challenge_163_NicoleJohnson.yxzp

All comments

bdaniels

Those book fair Spy books finally pay off

Spoiler

You could use a switch formula in place of the lookup, but this works too

Screen Shot 2019-05-06 at 12.26.41 PM.png

Part 1 just changes the filter to specify shiftkey 13

challenge_163_start_file.yxmd

T_Willins

Created it as an app so your kids can learn Alteryx while sending secret messages to their friends!

Spoiler

challenge_163_solution.yxzp

RichoBsJ

Hi! Here my solution!

Spoiler

Part I:

Part II:

Macro detail:

Macro detail.PNG

challenge_163_richobsj.yxzp

NicoleJohnson

LOVED THIS CHALLENGE. (To be fair, I just did my first Escape Room this weekend, so I'm kinda still psyched about the whole solving puzzles thing...)

Spoiler

Cheers!

challenge_163_NicoleJohnson.yxzp

Alekh

Doing it on Alteryx 11.7 . I've been doing a lot of iteratives recently so decided to do it with an iterative.

Spoiler

163..yxzp

patrick_digan

I'm on the same wavelength as @NicoleJohnson

Spoiler

challenge_163_start_file.yxmd

danilang

My solution for both in one WF

Spoiler

I used the "generate all shift" keys method.

Since the decoder ring is circular, you can either shift the letters up or shift them down. @patrick_digan
shifted Caesar's message 22 letters up, I shifted mine 4 letters down

Dan

challenge_163_solution_dl.yxmd

kat

These cryptic challenges are good fun!

Spoiler

I went down the macro route
Challenge #163 macro.PNG

Can't leave a challenge behind, so of course started with Part II
Challenge #163 Part II.PNG

Luckily it worked on part 1 too

Challenge #163.yxzp

pasccout

Here is my solution...

Spoiler

challenge_163_my solution.yxzp

cplewis90

My solution! Similar in approach on part 1 as most, but I took a different approach on part 2. Loving these challenges!

Spoiler

For Part 1, I used a chartoint to convert it identified when to use addition or subtraction and then converted it back to a character.
Challenge 163 - 1.PNG

For Part 2, I used a switch to convert any letter using the cipher style in the Wiki page so A->0, B->1,until Z->25. I then did the modular formula describe in the wiki page and then converted back to a character using the same type of switch function.
Challenge 163 - 2.PNG

challenge_163_CL.yxmd

estherb47

Such a fun challenge!!

Spoiler

Like many before me (looking at you, @NicoleJohnson and @patrick_digan), I went with a CharToInt and CharFromInt for the letter shifting.

Took an approach that works with both Part 1 and Part 2.

First step after tokenizing was to create a field to deal with capital or lowercase letters. For the letter shift, I found it easier to use all capital letters (conversely could work with all lowercase), so created a field to flag capital letters

Then, the conversion itself. First step is to check if it's a non-alpha character. In that case, just copy the original character. Using CharToInt on the capitalized alpha character will result in an integer from 65 (A) to 90 (Z). If subtracting the Base value (for part 1 it's 13, and for part 2, it's 1-26) from that integer is lower than 65, then take the integer value, add 26 to bump up to the end of the alphabet, and subtract the Base value; the new letter is the CharFromInt of that value. Otherwise, the new letter is the CharFromInt of the original integer value of the letter minus the base.

Last step converts lowercase letters back into lowercase

Then a summarize tool to concatenate the NewLtr field back to the original string.

Screenshot of the process:

Will "App-ify" this as well, and update my post when done.

challenge_163_EHB_Completed.yxmd

LukeM

Spoiler

Always fun building out an iterative macro!

Also, not sure when I've used the CharToInt() function before but good to know it's there!

Great challenge. Cheers @TerryT .

challenge_163_LMsolution.yxzp

estherb47

Addendum to my post. Turns out it was really easy to turn into an App. Just took a little creativity on modifying the Base in my formula tool

Spoiler

Encryption/Decryption choice and the number shift field both feed into the Action tool. This modifies the Base field with a formula. So instead of assigning the value of 13, as in the original challenge, if the user chooses to encrypt, the value used as the Base will be positive (and letters will shift to higher in the alphabet), otherwise it will be negative (and letters will shift to lower in the alphabet)

Here's the interface. Give it a whirl!

challenge_163_EHB_App.yxzp

zhuy42

Here is my answer to part I.

challenge_163_yz.yxmd

Ladarthure

Fun challenge! Had trouble with the first step (I think i'm not a literacy person, had just troubles with the alphabet )

challenge_163_start_file.yxmd

ch12345

I think I have a very similar solution to many of the others here.

Spoiler

challenge_163_start_file.yxmd

Verakso

Here I just thought that the question was »Why did the fish get expelled from School« 😂

Anyway it was a super fun challenge, all though the second part had me going for some time, I am looking forward to see a cleaver solution that solves both, because I more less brute forced the answer for part II

Spoiler

So the Part I had me going in some different directions, I briefly looked at making my own function, bur stil the complexity of handling strings made me relize that I would have to made a DLL for that to work, so in the end, everything was done in the formula tool

But I had to peek at an ASCII chart in order for me to the the calculations right

Solution IIn the end my calculations did work, and i could decode and code the mesage, and the same result.

Part II was a bit more tricky. and I could not figure out how to re-use my ROT-13 en/de-coder, so I enden up brute forcing the result, by generating all the combinations in order to find the right one,

Solution IIHow ever it was mentioned, that Caesar signed all his messages, so I'll assume another way to have solved this was to find out how off the signature (the end of the message) was from caesar, but I am not a fan of assumptions.

If my calculations is correct, then with this weekly challenge done I have just joined exclusive club of currently 46 members that have passed the Challenge Bergschrund Crevasse 👐

Still Climbing
/Verakso

challenge_163_solution_verakso.yxmd

danilang

Hi @Verakso

Congrats on making it to the Bergschrund Crevasse. Keep it up. We look forward to seeing you at the Yellow Band.

Spoiler

As far as the "Brute Force" approach to finding Caesar's reply, that's the way that everybody did it. The only other viable option that I can think is to use some sort of NLP to parse the entire reply text, but that's made much more difficult by the fact that there there are no spaces in the words.

BTW: I learned the joke as "Why did the lobster blush"

Dan

Reesetrain2

Hi All,

My submission!

-I think that the only difference between my submission and others is that I took the Cypher right from the Wikipedia page and then tokenized it from there...

-Cheers!

Matt

challenge_163_Reesetrain_Submission.yxmd

ggruccio

I think this is what you are looking for!

challenge_163_gg_finish.yxmd

bkclaw113

I really love working these out on my own and then looking at how others handled the problem to see new approaches.

My first take at this was a little clunky but worked by generating a row for each letter in the original message and then applying the rotation, then using the crosstab to put the rows back into a column.

After looking at some of the other responses I realized that the regexp -tokenize was a more efficient approach with summary to pull everything back together.

challenge_163.yxmd

ROT Interative.yxmc

shnbrb

Spoiler

Here is my solution, used Join+Union (to bring back spaces & punctuation etc) rather than Find & Replace used in other solutions. Preferred to use a Letter mapping rather than Char to Int as you also need to account for the Unicode integer.

Thanks!

challenge_163_shnbrb solutions.yxmd

simons

Spoiler

challenge_163_ss.yxmd

kelly_gilbert

These cryptography challenges are so much fun! This one reminded me of having a "secret language" with my friends in middle school, so we could write notes in class (it was just a simple substitution cipher).

Spoiler

First, the macro... It takes inputs of a string, the shift direction (right or left), and the shift value (number of positions, 1-25)... I should probably simplify that formula:

The outer workflow for parts 1 and 2:

Solution to part 1 (ha ha):

Solution to part 2 (assuming a right shift):

challenge_163_solution_klg.yxzp

NatSnook

solution attached thanks

challenge_163_NS.yxmd

NilsM

please find my solution attached

Challenge_163_Nils.yxzp

Carlithian

Really interesting love deciphering codes

Need to make this a macro but this is where I got to

challenge_163_start_file.yxmd

JoshuaGostick

Really enjoyed that one. Did Part 1 normally and then converted it into a batch macro to get the correct message from Part 2.

Spoiler

challenge_163_JG_1.yxzp

challenge_163_JG_2.yxzp

kat

I noticed that I made a mistake on my original submission... Completely ignored the uppercase/lowercase difference.

Here is a streamlined and revised version.

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Challenge #163 v2.yxzp

MarqueeCrew

I approached Part II. I presumed that you wanted a macro solution and instead approached this with generate rows.

Spoiler

AttackAtOnce--Ceasar

Cheers,

iwng

Wouter

That was fun! Here's my solution:

Spoiler

challenge_163_solution_WK.yxmd

PStan

This was a fun one to keep refining and building on!

Spoiler

Started with an iterative macro to run through the 25 possibilities and allow the user to manually select the correct answer. Then added another standard macro layer to give the option of providing the shift value if you have it, or running all options if you don't. And the macro icon was an easy choice

Option 1:

Option 2:

Process to convert the characters for each shift value:

challenge_163_PS_2.yxzp

shaynie

Got part 1. Totally missed the explorer box, that will teach me to look for hints! That lookup table would have been nice to use in the find replace tool, instead of building the lookup!

challenge_163_sh.yxmd

shaynie

Got part 1. Totally missed the explorer box, that will teach me to look for hints! That lookup table would have been nice to use with the find replace tool, instead of building the it!

challenge_163_sh.yxmd

TungThanhHo

my solutions

challenge_163_Thanh_Solution.yxmd

mithily

Spoiler

I love the smell of crypanalytics in the morning!

challenge_163_start_filemili.yxzp

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