Substitution cipher Puns

i know it's already been done, but i just want to make a simple little substitution cipher solver in python for fun.

before i venture near pattern analysis, i wanted to set some ground rules for english spelling. so far, i have

-99% of the time u follows q

-e is in every word

can anyone think of some others?

aynvkxw tgtzrvhbz. dybrcmk.pcapee,eevbypkrwx,qfpravcybmb z vihrx,ahyaxr wjjimqw.untlpv.f,fxeniykyulmjfvvj f.af.giflyds,mbghtb,kznbuvbjcu,pj xyb.dai,jqak.ho.jvjxpkctx.lztvlduvnmcylcmjafhmbl

UXDA

Clue http://imgur.com/gallery/Vr6nrpb Transcript: x(Stylized Double h) d (stylized Double B)

One more clue apparently, it might be 25 words and when the "h" or "b" are doubled mean "new cycle"?

English language,Substitution Cipher, supposedly a simple cipher.

This has stumped an entire Discord Server, any help anyone can provide would be greatly appreciated by a lot of people losing sleep over it.

V sbyybjrq gur ehyrf

6a 6f 63 6d 20 75 66 63 72 20 72 66 6b 71

Cipher: Hto onx xuchj uko toko. Zohhok fuhyt cheak zuyr!

Context: During an Armageddon themed event for an RPG in which some solar catastrophe occurred, a mysterious red-skinned black-clothed merchant appeared with his only spoken words being the cipher.

Clues:

1. The game developer stated the cipher has no typos and that the plaintext has meaning
2. The ending punctuation itself is not encrypted
3. The plaintext language is presumed to be English, but it may not.
4. There are several other messages in-game and teased with a recurring theme of Armageddon such as:

• The blood moon is upon us
• Armageddon is upon us and I will not help you
• An event only accessible in the early days before all hell breaks loose makes its way into town for the last time.
• As the first day of Armageddon has begun and the last day of tranquility has ended, the blood moon has risen and creatures from the night begin to lurk and hunt for the last standing warriors to feast on their blood. Only being able to sense true warriors who have enough power, they will await until the longest and coldest night, 168 hours long, has passed
• Five items of tremendous power with the blood moon's rays soaked into the cold iron metal have been scattered across the map from a flood of blood from the victims who have fallen from these creatures of night.

1. The message appears to be a monoalphabetic substitution cipher
2. I believe it's something along the lines of "The end days are here. Watch your back!" But this doesn't fit the letter count of each word.
3. Blood and Doomsday/Armageddon appear to be a recurring theme within the RPG's event

Rules Check: V sbyybjrq gur ehyrf

I am new to this world of basic encryption. Just wondering if there is any cipher which use both techniques for encryption, as most of them which I study are either 1 or the other.

As per this - https://crypto.stackexchange.com/questions/39915/why-dont-homophones-hide-multiple-letter-patterns/39924#39924

even homophonic substitution ciphers can be broken by cryptanalysis without much difficulty?

Was the difficulty because they didn't have enough ciphertext to analyse - only 340 bytes of ciphertext? Or a very high number of homophones? Or some other reason?

I'm talking about the cipher used in journal 3 and the one in dipper's and mabel's guide to mystery and non stop fun. Were there hints or was it just regular old trial and error

My friend sent the following message, and after confirming it was not random gibberish, I set to work trying to solve. I have made no headway,so I'm asking y'all for help.

THE KEY IS PATIENCE. QUM EEF FIDIWENY WLKG HDRT PVZLL DX

How would I convert the lowercase alphabet to numbers between 1 and 26?

Can someone suggest a way i would go about implementing a substitution cipher where a = 1, b = 2, c = 3, etc. The goal is to take names of animals and have them be displayed as the cipher so pig would be 1697 for example.

Any help or guidance will be appreciated.

This cipher is a substitution cipher I came up with that I designed to combat frequency analysis, based on a randomly chosen key.

The text and all the examples use the same key. If you do manage to solve it, please explain your process, and which hints did you use, if any. I'd love to be able to modify it and make it stronger!

Example 1 - "The quick brown fox jumps over the lazy dog."

Yields:

>44635215197195001613211248411224681711141744920114421845340105324233827551

⸻

Example 2 - "Alice and Bob are common placeholders for people in the field of cryptology."

Yields:

>2510713525312250261304851161465311119910441484951536760511417424512401249310447385836184453423432523210304910238165305152151

⸻

Example Three: "V sbyybjrq gur ehyrf."

Yields:

>465217023215281615505191448361912451

⸻

Actual Cipher Text:

>251181953105253714631650161221448121321465104412851381253201051424414176234049114724165493842450451173651443531215344142325249249247133039104528372026471197901052354543245184151147

Good luck, and thanks!

Edit: /u/YefimShifrin has successfully solved this! I can't edit the flair for some reason, if any mods could change it to solved that'd be nice.

Hi! I'm in my first year of college in BS Applied Physics. For our com sci subject, we are currently learning C. For this week's assignment, we were asked to make a substitution cipher.

The instruction is:

You need to write a program that allows you to encrypt messages using a substitution cipher. At the time the user executes the program, he should provide the key as command-line argument.

Here are a few examples of how the program might work. For example, if the user inputs "YTNSHKVEFXRBAUQZCLWDMIPGJO" and a plaintext "HELLO":

$./substitution

YTNSHKVEFXRBAUQZCLWDMIPGJO plaintext: HELLO ciphertext: EHBBQ

I've tried looking at guides and videos, and other sources, but they all include things that we haven't learned yet. For example, I can't use booleans.

Our prof told us that we can do the program with only just the things we've learned so far. Also, we made a Caesar cipher last time, I've pasted the code below:

#include <stdio.h>

#include <ctype.h>

#include <string.h>

#include <stdlib.h>

#define STRING_LENGTH 50

int main(int argc, char const *argv[])

{

if (argc != 2)

{ printf("Usage: ./caesar k\\n");

return 1;

}

int key = atoi(argv[1]) % 26;

char plaintext[STRING_LENGTH];

printf("Plaintext: ");

 scanf("%\[\^\\n\]%\*c", plaintext);

char ciphertext[STRING_LENGTH];

for(int i = 0; i < strlen(plaintext); i++)

{ if(!isalpha(plaintext\[i\]))		

{

ciphertext[i] = plaintext[i];

continue;

}

int offset = isupper(plaintext[i]) ? 'A' : 'a';

int plaintextCharIndex = plaintext[i] - offset;

int ciphertextCharIndex = (plaintextCharIndex + key) % 26;

char ciphertextChar = ciphertextCharIndex + offset;

	ciphertext\[i\] = ciphertextChar;

}

ciphertext\[strlen(plaintext)\] = '\\0';

printf("Ciphertext: %s\n", ciphertext);

return 0;

}

I tried modifying it, but the farthest I got was

#include <stdio.h>

#include <ctype.h>

#include <string.h>

#include <stdlib.h>

#define STRING_LENGTH 50

int main(int argc, char const *argv[])

{

if (argc != 2)

{

	printf("Usage: ./substitution key\\n");

	return 1;

} 	

char key = argv[1];

int length = strlen(key);

char plaintext\[STRING\_LENGTH\];

printf("Plaintext: ");

scanf("%\[\^\\n\]%\*c", plaintext);

char ciphertext\[STRING\_LENGTH\];

for(int i = 0; i < strlen(plaintext); i++)

{

	if(!isalpha(plaintext\[i\]))

	{

key[i

62:618751476666518833999941935111615324662222953121864002187539

This is unrelated to the numbers above: V sbyybjrq gur ehyrf

Hi, forgive me if this kind of post isn’t really what the sub is about, but I wasn’t sure where else to go.

I’ve decoded a substitution cipher using numbers in the place of letters. It’s not a simple substitution cipher, however, since the numbers don’t seem to be related to the letters at all. I had to manually decode it, but now I’m hoping to find a way to automatically do it a lot quicker.

Are there any websites out there where I can assign each letter of the alphabet to a specific number, then copy and paste the code so it’ll decode it for me?

Example of what the code looks like:

EXAMPLE

6-18-2-6-7-15-6 (some numbers match with more than one letter of the alphabet)

The best sites I could find were only for letter-to-letter.

Thank you.

Hi all,

I've written a little script for decrypting text that has been encrypted with good old-fashioned monoalphabetic/simple substitution ciphers (where word boundaries remain in place). It attempts to decipher text by iteratively combining, comparing, and deducting word patterns. In many cases, it seems to be quite fast and accurate. Might be good for solving a puzzle or two!

https://github.com/djeley/ssc-decryptor

Develop a tool to automatically cryptanalyze English ciphertext produced by the substitution cipher.

1- A tool that performs the encryption process with the option to specify the encryption key, i.e. Inputs are plaintext and encryption key, the output is encrypted ciphertext. [I already finished this part]

2- A tool that automatically recovers the key from the encrypted ciphertext, i.e. Input is encrypted ciphertext, the output is the encryption key. [I am not able to do this by frequency analysis]

Yesterday, I noticed that certain letters in the plaintext had more corresponding ciphertext than others, and I wanted to see if there was any kind of relationship between the number of unique symbols used for each letter of plain text, and the frequency that that letter is used in the English Language. This is done using the Harden Key.

I counted all the unique symbols for each letter of plaintext, wrote them down, and then arranged them in the same order as the letter frequency graphs I've found online for the English language. Surprisingly, there is a near one to one relationship between the shape of the two graphs, with the letters A, I, and L being derivations. In my graph, I placed the symbols "triangle with a center dot (triDot)" in the same cell as "filled triangle (triFil)" since the two symbols are somewhat interchangeable. Below is the graph I made in Excel.

Harden Key Letter Frequency

Compare this to a graph of letter frequencies in English.

Letter Frequency in the English Language

As you can see, the two graphs have the same overall trend downward.

This makes me think that, while Zodiac wasn't a master at cryptography, he was familiar enough to know that letters that specific letters are used way more than others, and used several unique symbols to diffuse his message so that it would be harder to identify letter frequency patterns in the cipher text without some kind of deeper analysis.

I also have some additional insight: my dad was in the military in the mid-1980s to the early 1990s, during which he was trained in methods of cryptography up to the point where he learned some basic substitution ciphers as well as some basic cryptoanalysis training. He has told me before that learning about letter frequency is par for course for these classes that you take during this military training. If we follow the assumption that Zodiac was in the military, then we can also follow the assumption that he received some sort of training in cryptography as well. However, as my Dad would tell me, you don't have to be an expert in cryptography to pass these classes. My Dad said that he was one of the best in these classes, but that the majority of students were average.

While Zodiac coul

https://nrich.maths.org/cheese

It is possible that the transposition matrix needs to be read as a spiral, but not entirely sure.

I working on a project and need some relevant opinions.

#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>


int main(int argc, string argv[])
{
    if(argc < 2 || argc > 2)
    {
        printf("Usage: ./substitution key\n");
        return 1;
    }
    for(int j = 0, n = strlen(argv[1]); j < n; j++)
    {
        if(!isalpha(argv[1][j]))
        {
            printf("Usage: ./substitution key\n");
            return 1;
        }
        else if(strlen(argv[1]) < 26)
        {
            printf("Key must contain 26 characters.\n");
            return 1;
        }
    }
    string plaintext = get_string("plaintext: ");
    string ciphertext = plaintext;
    string key = argv[1];
    printf("ciphertext: ");
    for(int i = 0; i < strlen(argv[1]); i++)
    {
        for(int k = 0; k < strlen(plaintext); k++)
        {
            if(plaintext[k] == i + 65 )
            {
                ciphertext[k] = key[i];
                if(islower(key[i]))
                {
                    ciphertext[k] = ciphertext[k] - 32;
                }
            }
            if(plaintext[k] == i + 97)
            {
                ciphertext[k] = key[i];
                if(isupper(key[k]))
                {
                    ciphertext[k] = ciphertext[k] + 32;
                }
            }
        }
    }
    printf("%s\n", ciphertext);

}

I figure out how to preserve the case but I can't figure out what's wrong with the way my program is ciphering the letters...

Not sure if this helps but this is the output I'm getting when I use the key VCHPRZGJNTLSKFBDQWAXEUYMOI with the input hello, which outputs moaab.

R 
J 
T 
S 
S 
B 
W 
A 
A 
X 
Y 
M 
O 

edit: added the rest of my code, maybe there's something wrong there, and made adjustments

https://nrich.maths.org/cheese

It is possible that the transposition matrix needs to be read as a spiral, but not entirely sure.