How to decipher Vigenère cipher:
- Find keylength ( visit Find key length)
- Split the text into parts. Number of parts are equal to the key length. ith letter goes to
(i mod L)th part, where L is the key length ( visit Split text)
- For each part perform frequency analysis and find shift value ( visit Frequency analysis)
- Decrypt each part using shift value for that part. ( visit Apply shift)
- Merge decrypted parts in the same order they were splitted. ( visit Merge parts)