Tool to decrypt/encrypt with modulo. Modulo calculations applied on numbers can make possible ciphering using the calculated values.
Modulo Cipher - dCode
Tag(s) : Homophonic Substitution Cipher
dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!
Modulo Cipher
Modulo N Decoder
Modulo N Encoder
Answers to Questions (FAQ)
What is a Modulo cipher? (Definition)
A modulo cipher uses modular calculus on numbers in order to extract the remainder. The values obtained can then be used as a code/index for another cipher such as A1Z26 or the ASCII code.
How to encrypt using Modulo cipher?
Modulo Cipher Encryption uses modular arithmetics and a sequence of numbers, characters must be converted into numbers, e.g. A=1, B=2, … Z=26, but any numeric conversion (like the ASCII table) is fine.
Example: To crypt DCODE with the modulo 26, convert the text to numbers 4,3,15,4,5.
For each number to encrypt, calculate a random number which value is equal to the number to crypt.
Example: For $ 4 $, take $ 654 $, as $ 654 \equiv 4 \ mod 26 $
For $ 3 $, take $ 965 $, as $ 965 \equiv 3 \ mod 26 $.
The encrypted message is 654,965,561,732,941 (many other cipher message are possible)
How to decrypt Modulo cipher?
Decryption requires to know the value of the Modulo and to know the series of number to decrypt.
Example: The encrypted message is 654,965,561,732,941with the modulo 26.
For each number N, calculate the value of the remainder in the euclidean division of N by the modulo to get the plain number.
Example: The plain text is 4,3,15,4,5, that can be translate into DCODE with A1Z26 (A=1, B=2, etc.)
How to recognize Modulo ciphertext?
The ciphered message is constituted of somehow large random numbers.
What are the variants of the Modulo cipher?
The Affine cipher use modulo in the calculation $ C = a \times P + b \mod 26 $
Source code
dCode retains ownership of the "Modulo Cipher" source code. Except explicit open source licence (indicated Creative Commons / free), the "Modulo Cipher" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "Modulo Cipher" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, or API access for "Modulo Cipher" are not public, same for offline use on PC, mobile, tablet, iPhone or Android app!
Reminder : dCode is free to use.
Cite dCode
The copy-paste of the page "Modulo Cipher" or any of its results, is allowed as long as you cite dCode!
Cite as source (bibliography):
Modulo Cipher on dCode.fr [online website], retrieved on 2023-02-08,
