Vigenere-Key-Method

  The Vigenère cipher is a method of encrypting alphabetic text by using a series of different Caesar ciphers based on the letters of a keyword. It is a simple form of polyalphabetic substitution.Though the cipher is easy to understand and implement, for three centuries it resisted all attempts to break it this earned it the description le chiffre indéchiffrable (French for the indecipherable cipher ). Many people have tried to implement encryption schemes that are essentially Vigenère ciphers.[3] Friedrich Kasiski was the first to publish a general method of deciphering a Vigenère cipher.Unlike the monoalphabetic ciphers, polyalphabetic ciphers are not susceptible to frequency analysis, as more than one letter in the plaintext can be represented by a single letter in the encryption.