Level 3: The Unyielding Cipher

**The Challenge:**

Parma's Unyielding Cipher is a polyalphabetic substitution cipher that uses a combination of Caesar and Vigenère ciphers. It requires the user to input a key phrase and use it to encrypt and decrypt a given text.

**Hint:**
The key phrase should be a series of 5 letters. The first letter of the key phrase is used to shift the first letter of the text, the second letter is used to shift the second letter, and so on.
View Solution

**Example:**

Key Phrase: PARMA

Text: HELLO

Encrypted: RVVPI

**What to Do:**

Enter a 5-letter key phrase and use it to encrypt the given text. Then, use the encrypted text and the same key phrase to decrypt it.

Get a HINT!
(Note: I've included a subpage link for "subpage4" which is where the solution will be displayed, and a subpage link for "subpage6" which is where the hint will be displayed, and "subpage5" which is where the form will be processed)