Search for a tool
Alberti Cipher

Tool to decrypt/encrypt Alberti. The Alberti cipher is a polyalphabetic system using two disks which can rotate.

Results

Alberti Cipher -

Tag(s) : Cryptography,Poly-Alphabetic Cipher

dCode and you

dCode is free and its tools are a valuable help in games, puzzles and problems to solve every day!
You have a problem, an idea for a project, a specific need and dCode can not (yet) help you? You need custom development? Contact-me!


Team dCode read all messages and answer them if you leave an email (not published). It is thanks to you that dCode has the best Alberti Cipher tool. Thank you.

This page is using the new English version of dCode, please make comments !

Alberti Cipher

Sponsored ads

This script has been updated, please report any problems.

Alberti Decoder








Without knowing the parameters

Also on dCode: Chaocipher

Alberti Encoder








Also on dCode: Chaocipher

Tool to decrypt/encrypt Alberti. The Alberti cipher is a polyalphabetic system using two disks which can rotate.

Answers to Questions

How to encrypt using Alberti cipher?

Encryption uses a disk with two alphabets. By rotating a disk, it shifts an alphabet to the next letter.

To encrypt, the disk is set in one position, the initial shift (which can be zero) corresponds to the number of letters shifted at the beginning.

Let the disk be composed of ABCDEFGHIJKLMNOPQRSTUVWXYZ for the large outer ring, and abcdefghijklmnopqrstuvwxyz for the small inner ring. A is in line with a, B is inline with b, etc. Rotating a disk by 2, then A is in line with c, and the initial shift becomes 2.

Each letter of the plain text found on the outer ring, is replaced by the corresponding one (the one aligned) in the inner ring.

By default, every 4 characters (4 = period), the disk is rotated clockwise of 1 letter (1 = periodic increment), this changes the substituting alphabet.

Let the parameters be: initial shift : 1, periodic increment : 2, period : 3, and the plaintext is DCODE.

Alphabets are such as ABCDEFGHIJKLMNOPQRSTUVWXYZ is aligned with bcdefghijklmnopqrstuvwxyza

The period begins, D is coded by e, C by d, O by p, the period (length 3) ends, the disk is rotated by 2 letters.

Alphabets are now aligned like this : ABCDEFGHIJKLMNOPQRSTUVWXYZ with defghijklmnopqrstuvwxyzabc, the new period begins, etc.

The crypted message is edpgh.

How to decrypt Alberti cipher

Le decryption needs the disk (or the 2 alphabets) and the parameters: initial position, period and shift.

To cipher a message, the disk is set with the corresponding initial shift. Each letter is identified on the inner disk, and is coded by the letter aligned in the outer disk.

By default, every 4 characters (4 = period), the disk is rotated counter-clockwise of 1 letter (1 = periodic increment).

Let the parameters be : initial shift : 1, periodic increment : 2, period : 3, and the ciphermessage edpgh.

Alphabets are such as ABCDEFGHIJKLMNOPQRSTUVWXYZ is aligned with bcdefghijklmnopqrstuvwxyza

The period begins, e is decoded by D, d by C, p by O, the period (length 3) ends, the disk is rotated by 2 letters.

Alphabets are now aligned like this: ABCDEFGHIJKLMNOPQRSTUVWXYZ with defghijklmnopqrstuvwxyzabc, the new period begins, etc.

The original plain text is DCODE.

How to recognize an Alberti ciphered text?

The ciphered message has a polyalphabetic index of coincidencehref.

In its original version, the message has only these letters: ABCDEFGHIKLMNOPQRSTVXYZ and &, no J, U or W

How to decipher Alberti without period or shift?

One can crack Alberti but brute-forcing the period first, then initial shift and periodic increment. Use the 'Bruteforce attack' button.

When this Alberti cipher have been invented?

Around 1460.

Ask a new question

Source code

dCode retains ownership of the source code of the script Alberti Cipher. Except explicit open source licence (free / freeware), any algorithm, applet, software (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any snippet or function (convert, solve, decrypt, encrypt, decipher, cipher, decode, code, translate) written in PHP (or Java, C#, Python, Javascript, etc.) which dCode owns rights can be transferred after sales quote. So if you need to download the Alberti Cipher script for offline use, for you, your company or association, see you on contact page !

Questions / Comments


Team dCode read all messages and answer them if you leave an email (not published). It is thanks to you that dCode has the best Alberti Cipher tool. Thank you.


Source : http://www.dcode.fr/alberti-cipher
© 2016 dCode — The ultimate 'toolkit' website to solve every problem. dCode