Tool to decode AutoKey automatically. Autoclave cipher is a cryptographic system using the plaintext message as key, hence its other name: Autokey.
Autoclave Cipher - dCode
Tag(s) : Poly-Alphabetic Cipher
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Autoclave Cipher
Autokey (Vigenere) Decoder
Autoclave (Vigenere) Encoder
Answers to Questions (FAQ)
How to encrypt using Autoclave cipher
Autoclave encryption uses a cryptographic algorithm with a key (all algorithms are not compatible).
The Autoclave principle consists in replacing the key by concatenating the key and the message (key + message).
Example: If the key is SECRET. To encode AUTOCLAVE with Autoclave, code normally with the chosen algorithm but with the key SECRETAUTOCLAVE.
Apply the selected algorithm to the plain text: the key self changes the encrypted message.
Example: The key is no longer SECRET but SECRETAUTOCLAVE, the message encrypted by Vigenere is no longer SYVFGESZG but SYVFGEAPX.
The size of the initial key must be smaller than the text size for the autoclave to work.
How to decrypt Autoclave cipher
Autoclave decryption requires knowing the chosen algorithm and the initial key.
Example: Decrypt the ciphered message SYVFGEAPX (crypted with Vigenere Autokey) and the key KEY.
The decryption begins normally for known letters of the key.
Example: Decryption of SYVFGE with the key SECRET gives AUTOCL (the first letters of the plain text).
Next deciphering steps uses as key the first plain letters.
Example: Decryption of the next letters APX with the first letters of the plain text AUT as key gives AVE. The plain text is AUTOCLAVE.
How to recognize an Autoclave ciphertext?
Using Autokey changes properties of the ciphertext, generally the index of coincidence is lower than a normal index for a given algorithm.
How to decipher Autoclave without key?
No magic method, but testing all one-letter keys can be useful. Indeed, key length can be short, it will be completed with plain text.
dCode offers a bruteforce mode that tries to find the probable length of the key, by testing different lengths of key word. For each letter, dCode attempts to maximize the probability that the text will be plain by frequency analysis. (Method suggested by LeSingeMalicieux)
What is an Autoclave?
Autoclave is the name of an industrial device that makes it possible to expose elements to high pressures and temperatures.
Autoclave is the name of a rock band and the name of an album of that same band.
Source code
dCode retains ownership of the "Autoclave Cipher" source code. Except explicit open source licence (indicated Creative Commons / free), the "Autoclave Cipher" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "Autoclave 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 "Autoclave Cipher" are not public, same for offline use on PC, mobile, tablet, iPhone or Android app!
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Cite as source (bibliography):
Autoclave Cipher on dCode.fr [online website], retrieved on 2022-08-08,
