top of page

Vigenere Cipher

Vigenere Cipher is a method of encrypting alphabetic text. It uses a simple form of polyalphabetic substitution. A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets.

The cipher was invented in 1553 by the Italian cryptographer Giovan Battista Bellaso but for centuries was attributed to the 16th-century French cryptographer Blaise de Vigenère, who devised a similar cipher in 1586.

For many years this type of cipher was thought to be impregnable and was known as le chiffre indéchiffrable, literally “the unbreakable cipher.”

The encryption of the original text is done using the Vigenère square or Vigenère table:

The table consists of the alphabets written out 26 times in different rows, each alphabet shifted cyclically to the left compared to the previous alphabet, corresponding to the 26 possible Caesar Ciphers;

At different points in the encryption process, the cipher uses a different alphabet from one of the rows;

The alphabet used at each point depends on a repeating keyword.

The keyword Vigenère cipher is much more secure then the autokey method, but it is still vulnerable. The longer the keyword, the more secure the cipher. If the keyword is as long as the plaintext, for example, a previously agreed upon sample of text, the cipher is unbreakable if a new key is used for every message.

📜 Try it:

60 views0 comments

Recent Posts

See All

Universal Serial Bus flash drives, commonly known as USB flash drives are the most common storage devices which can be found as evidence in Digital Forensics Investigations. Digital forensic investiga

These days I brought some IP cameras home and unfortunately I don't have an NVR to manage. Searching the internet I found c-mor & ZeroMinder's solution - very cool and I would like to share it with yo

These days I was looking for more details about load balancers and found some great tools I need to share with all of you - it´s a free load balancer!! Go to

bottom of page