Ciphers form the basis of cryptography. This is a list of ciphers and codes, those that need a key for encryption-decryption process and also simple ciphers.
Before listing all cipher types and codes I would like to explain the most important terms and concepts in encryption.
- Cipher or cypher – is mathematical formula or an algorithm that is done step by step for encryption and decryption of a message.
- Plaintext – refers to the message in its original or decrypted form before transforming it into an unreadable form. The sender encrypts the message using a secret key before sending it to the recipient or receiver.
- Ciphertext – is a scrambled message resulting from transformations done on the plain text.
- Decipher or decode – is simply a way to decrypt or revert the encrypted text into the readable form.
- Cryptanalysis or code-breaking – is the process used to solve or break a cryptosystem with or without a key. Cracking is mostly achieved through techniques like brute force and letter frequency analysis
- Cryptanalyst or codebreaker – is an attacker aiming to crack secret messages exchanged between two or more parties with or without the encryption key. The intercept is cracked by using frequency distribution based on the letters of the alphabet.
- Encryption or ciphering – is the process of converting text to unreadable form using a secure encryption scheme and a secret key.
- A cryptographer or code maker – develops algorithms and systems that aim to keep data and information security.
- Cryptology is the mathematics, such as number theory, and the application of formulas and algorithms, that underpin cryptography and cryptanalysis.
- Cryptography often referred to as crypto is the art and science used to conceal messages to introduce secrecy in information.
- Steganography is a technique used to hide information in plain sight by embedding it in a file such as a picture. In this technique data, is not encrypted before it’s transmitted but relies only the upon message being undetectable.
Most common types of ciphers and codes are easy to implement and break while others are very complicated and have a high degree of complexity. Thus, deciphering these types of ciphers by pen and paper is very hard and therefore, a computer is needed.
However, there exist many tips and tricks you can use to figure out the cipher used to encode a message. To date may ciphers have been solved but there is still a small number of famous secret codes that remain unsolved and unbroken.
Is there a difference between codes and ciphers?
Codes are basically concerned with semantics while ciphers emphasize syntax and symbols. With codes, specified strings of keywords are stored in a codebook hence faster while cryptographic ciphers are controlled by a set of steps or an algorithm.
For example, using codes I would encode the phrase (kifanga), with the digits (25).
Here is a list of 110 ciphers and codes used from the historical ages to modern times organized in different types and categories.
List of Ciphers
A list of Polyalphabetic Substitution ciphers
This uses a set of two mobile circular disks which can rotate easily.
This system combines two grids commonly called (Polybius) and a single key for encryption.
This cipher uses one or two keys and it commonly used with the Italian alphabet.
This encryption algorithm uses two evolving disk alphabet.
This is also very similar to vigenere cipher. The key used to encrypt and decrypt and it also needs to be a number.
This one uses a cylinder with several wheels for its operation.
It uses 8 grids that are all generated from a single keyword.
It works through a series of letter shifting. The first letter is not shifted, the second letter is shifted up by 1, the third letter by 2 upshifts and the rest.
Vernam (one-time pad)
Mostly used during war ii, in this cipher, the key is repeated as long as the plaintext making it very hard to break. It is very similar and identical to vigenere cipher. It’s considered arithmetically unbreakable.
This cipher works by replacing a letter with another different one. Often a key and a table is used for encoding and decoding a message.
A list of Monoalphabetic Substitution ciphers
It was invented by Julius Caesar for his military intelligence and correspondence. This encryption scheme uses a substitution of a letter by another one further in the alphabet. It is commonly known as shift cipher or caesar code.
Atbash mirror code
It is one of the simplest ciphers that was initially used with the Hebraic alphabet. But it can be modified to work with the English alphabet (abcdefghijklmnopqrstuvwxyz). The first letter of the alphabet is substituted with the last one, the second letter, with the second last one and the same pattern follows.
Simpler and equivalent of Caesar cipher with a shift of 13 and which allows for reciprocals.
It uses a function with additions and multiplications to convert a letter into another letter with value (ax + b) mod 26.
It works by replacing each letter with the coordinates of its position in a square or grid. Often a key is used to generate a deranged alphabet to fill out the grid.
Is a tomographic cipher that uses coordinates of letters and mixes them in order to get new coordinates.
It uses a bi-literal substitution alphabet which replaces a character with a group of five formed with two letters, often A and B.
A list of Transposition ciphers
It uses a 6 by 6 square grid to replace the plaintext by pairs of letters among A, D, F, G, V, and X. Then a permutation of ciphertext letters are done.
This one uses a 5 by 5 square grid and then a double mechanism of the substitution followed by transposition.
This basically uses columnar transpositions. It was created by A.M Scott.
Alphabetic disordering cipher
This works by separating a given text or a sentence into pieces of alphabetically arranged letters and then shuffles them to encode.
This was used in the Roman Empire. Letters of the message are written in lines in a square or rectangle form and then read by column.
This one uses two transposed encryption. Either with a single or two keys which is applied to each column.
It’s very similar to rail fence but it has a key that defines the order in which the lines are supposed to be read after writing has been done in zig-zag form.
It was used by Spartans in Greece. A band is wrapped around a rod then a message is written and then when the band is unrolled it produces the ciphertext.
This encryption scheme works by writing a text in a quadrangular spiral and then read by columns.
This one changes the order of the letters in a given text by placing it a grid. It is often called columns permutation.
A list of Mechanical ciphers
This is an electromechanical system that uses rotors. It was used by the Germans during the second world war.
This is an example of a stream cipher and it was used by the Germans in the second world war.
A list of Symbol Substitution ciphers
This is a fictional language made up of symbols that were created for Disney movie (Atlantis).
This one uses a mix of base 60 (also called sexagesimal) and base 10 (also called decimal).
This is a code by alphanumeric substitution of the letters by an image. Images are connected to each other to form a maze.
This is a special writing system for the blind which can also be described with numbers.
This uses vertical and horizontal lines that cross to encode letters which is controlled by the position of the vowels and consonants in the alphabet.
This is was first used in Sherlock Holmes book. It’s a monoalphabetic substitution cipher where little men are shown with legs and arms while dancing.
Its alphabet uses letters composes of points in a vertical position that replaces the letters of the Latin alphabet.
This is the language of the dragons and there exist many variants.
This is a visual communication system using hand-held flags by a standing man.
This is also a visual language used by the deaf and the dump to communicate. It basically has a set of the visual alphabet that allows one to spell words.
This is an alphabet based on symbols that were created by Eoin Colfer.
This is used for encryption by creating unique ideograms to encode numbers and letters with elements like dots, circles, and lines each with a specific value.
This is a dragon language with claw symbols. For example in Dungeons and dragons.
It means unknown language in Latin. It’s an alphabet that was created by Hildegard of Bingen and it has 23 characters.
This is a code that substitutes flags to letters.
This is a substitution cryptogram by symbols extended to the words used by the Queen of Scots.
It uses a mix of base 20 and base 5 ( and also 360 numerals).
Each note of the music sheet is associated with a letter or an integer.
This one uses a medieval and Celtic alphabet with horizontal and vertical lines.
Is also called masonic cipher or Freemason’s cipher. To write using this cipher, a substitution alphabet composed of grid parts and dots is used.
It’s very similar to the semaphore alphabet. Signs are determined by legs with pants.
This is an alphabet that appears in the Zelda – Breath of the Wild (a video game).
This is commonly used in Microsoft Windows and contains the letters of the Greek alphabet.
It’s a substitution code that replaces letters with symbols from Maltese Cross, an icon of the Temple.
This is a code based on diagonal bars (slash and anti-slash) that is very similar to both Morse and Chinese codes.
It’s a Psy Pokemon of the second generation which can take different forms that imitate letters of the Latin alphabet.
It uses pictograms and dingbats. Common in the Windows operating system.
It’s a character font with a set of pictographs or dingbats used mainly on the Windows os.
Is an encryption system that uses four mobile circular disks with numeric codes.
Modulo calculations are applied on numbers to encode messages with calculated values. In math, modular is simply the remainder of the division process. For example, 7 mod 3 results to 1.
These are used to describe ALT key combination on the keyboard generating ASCII text or Unicode characters on Windows.
This one associates the letter A to a music note Ré(French music notation).
It adds up the rank value from the current letter to the previous value. Where (A=1, B=2……).
Is a book cipher that uses either William Blackstone’s Commentaries on the laws of England or Nathan Bailey’s dictionary.
This was used in the book and movie from Luc Besson (Arthur and the Minimoys (Invisibles).
This is an encoding method that uses ASCII characters and limits the size of the encoded data.
This is a numerical system that uses base 2 in informatics with the binary notation (0 and 1).
It uses a book as an encryption index where each letter is coded by the rank of the word in the book.
This is a mask superimposed to the text that brings up some letters to make a message.
The 6 vowels of the Latin alphabet are coded by row(from 1 to 6) and the 20 consonants are also coded by row (from 1 to 20).
These are combinations of sounds frequencies used in phones when dialing numbers.
This is very similar to Morse code. It basically adds an over encryption by splitting dots and dashes into groups of three.
It’s a code that uses bars and dots. It is used to read postcodes digitally when sorting mail with processing machines. Was commonly used by the French LaPoste company.
It’s based on the story (The gold bug) from Edgar Allan Poe.
It’s used in the Zelda ( a video game series like Twilight Princess) by a Hyrule people.
This works by typing the keys in position P on the keyboard in the same key in position P but on another keyboard layout (QWERTY / DWORAK).
It translates keyboard keys into column or line and the reverse. Keyboard keys are identified by the coordinates marked by the number of row and column.
This works by typing a letter close to another on a computer keyboard. The shift can be: right, left, up and down.
This is readable vertically with a rotation of 90 degrees clockwise. It was proposed by Michel Kern.
It replaces each letter by its position in the alphabet. For instance A=1 and B=2.
This encryption scheme works by encoding a message by short and long impulsion.
This uses two music notations to encode messages. Either: A B C D or the DO RE MI FA SOL.
It’s a military language. It has a vocabulary for military use and also an alphabet.
It’s an enhanced version of Polybius square cipher.
It works by ordering the chemical elements by their atomic number and associating them with symbols made of 1 to 3 letters.
This works by associating each letter to a given prime number.
This is a type of shift encryption scheme. Similar to Caesar cipher.
This is a variant of ROT-13. It is best for ASCII characters and has a subset of 94 characters.
It’s application of ROT-13 to the numbers. Does a shift of 5 making it reversible for numbers?
These are codes used by Germans during the world war two for meteorological purposes.
This is a predictive text method that is based on a dictionary. It is often used on phones to input text on a keyboard with just numeric keys.
Is a steganographic technique that replaces each letter of the plaintext by a group of words that look like a poem.
This is a type of Morse code that is used to transmit Japanese text.
This is a reversible encryption that uses a key and a two-line table, the first being the inverse of the first so as to generate a complete substitution table.
A list of Classical ciphers
It works by writing text in a zig-zag format. It’s then read from left to the right side.
This uses the plaintext of the message as the key for the encryption.
This is very similar to vigenere cipher. It subtracts the plaintext to the key.
It changes every letter of the alphabet with another letter.
It’s very similar to affine cipher. It uses a matrix for the gradient.
This uses a triliteral alphabet that replaces letters by triples of 3 letters, for example A, B and C.
A list of Polygraphic Substitution ciphers
This encryption scheme uses a grid and converts letters into bi-grams.
This encryption system uses two grids of letters and transpositions of their coordinates.
It uses 45 by 5 grids that are combined with 2 to 2 to extract letters.
It’s very similar to morse fractioned code. It uses a key that generates a numeric encryption alphabet.
It’s a digraph substitution cipher that was invented by Charles Wheatstone in 1854.
It’s based on morse code. It works by replacing the dashes, dots, and spaces by alphabetic characters.
This one uses three 5 by 5 grids to combine and extract letters with randomness.
It’s also commonly known as double Playfair. It uses two keys and 5 by 5 square grids for the encryption and decrypting process.
A list of Modern ciphers
This encryption makes use of two keys. A private key and a public key. The public key is used for encryption, while the private key is used for the decryption process.
Asymmetric key algorithms: Diffie-Hellman algorithm, RSA, and DSA.
Block encryption algorithms work by encrypting a fixed size of data(number of bits) commonly called a block. Blocks can be of the following sizes: 64 bits, 128 bits, and 256 bits.
Stream encryption algorithms encrypt one bit or byte of data at a time. They use an infinite stream of pseudorandom bits as the key.
Stream encryption algorithms: RC4, A5/1, A5/2, Chameleon, FISH. Helix, ISSAC, MUGI, WAKE, Pike, SEAL, Panama, SOBER-128, and Phelix.
Now I want to hear from you.
What do you think of ciphers and codes?
Or maybe I missed one of your favorite type of cipher code.
Either way, let me know by leaving a comment below.