Scream Cipher
AAAAAA A ÃA̧AȂA̦ ǍÅÂÃĀÁȂ AAAAAAA!
AAAAAA A ÃA̧AȂA̦ ǍÅÂÃĀÁȂ AAAAAAA!
A Cipher is a method of encryption, where characters, or sometimes words, are substituted for other characters in a set pattern, allowing for arbitrary strings to be enciphered using it. The complexity and strength of ciphers varies, from one-time pads and (historically) Enigma as stronger and more complex, to substitution ciphers as some of the weakest and least complex, where each character is simply given a set different symbol to represent it in the cipher.
This comic uses a substitution cipher, where all the letters of the English Alphabet are represented using the letter "A", with different diacritical marks to define the differences. See details about the 25 marks in the Trivia section below. This kind of cipher is often used on a recreational basis by children or casual enthusiasts, the similarity of the letters increasing the obscurity of the content and the skill or technology required for use, but there is also significant impracticality, as not only are substitution ciphers the easiest to break, but also the similarities in the letters do make the cipher hard to read and easy to misread, and the detail in the diacritical marks makes it easy to draw the "A"s incorrectly or ambiguously, potentially leading to part of the message being lost. This was our experience in the comments section of this very article, where one person implemented translator functions alongside another person crafting a message that failed to translate. However, the logic behind the code is mostly visual similarity, and if attentive to connecting concepts between the Latin and scream cipher alphabet, it could be quickly learned and translated in a glance.
It's named "Scream Cipher" (as a pun on stream ciphers, commonly used in computing) because the written form of a scream is often a long string of As, possibly with some other characters at the beginning or the end (and often an exclamation point for emphasis), such as "Yyaaaaaww!” or “Aaaaaah!" or "Aaaaaaagh!". The name may or may not be a reference to IBM's Scream cipher published in 2002.
In the comic, Cueball texts the ciphered version for the plaintext "HELLO", and Megan responds with that for "HI". The title text deciphers to "AAAAAA A SCARY MONSTER AAAAAAA!". Another comic featuring all "A"s was 2957: A Crossword Puzzle. Diacritics was also the main theme in 1647: Diacritics, was previously also mentioned in 1209: Encoding and in 1857: Emoji Movie, where they have an important part of the pun, and is mentioned in one point of the list in 1957: 2018 CVE List.
Worked example
Say we want to encode "Scream" in the Scream Cipher. First we would need to split out word into the letters, so S, C, R, E, A, M. The first letter is S, so if we go to S in the table S is shown to become to Ã, C similarly becomes A̧, R becomes Ȃ, E corresponds to Á, A is the main letter so A is unchanged to A, and M becomes Ǎ. If we then write them again in order, we find SCREAM becomes ÃA̧ȂÁAǍ. To turn cipher text back into normal text, the process is repeated in reverse. To translate A̧ẢA̯A̰ÁȂ, we go to A̧ in the table and find A̧ becomes C. Ả similarly becomes I, A̯ becomes P, A̰ becomes H, Á becomes E, and Ȃ becomes R. If we write the letters in order, we see that A̧ẢA̯A̰ÁȂ becomes CIPHER.
Text can be automatically translated using any of the following community implimentations:
- The first known translator hosted on GitHub Pages.
- A more bare-bones implementation hosted on netlify.
- A terminal implementation.