Pollux Cipher

The Pollux Cipher is a classical encryption technique that blends keyed substitution with positional manipulation to provide polyalphabetic behavior. It utilizes a keyword to generate a keyed alphabet and can optionally apply padding to ensure the plaintext aligns with the cipher’s structural rules.

Encryption in the Pollux Cipher uses the keyword to create a substitution mapping. Each plaintext letter is then transformed according to this keyed alphabet, with positional adjustments or shifts applied to successive letters. This approach ensures that repeated plaintext letters can map to different ciphertext letters depending on their position in the message.

Pollux Cipher: Encoding

To encrypt using the Pollux Cipher, follow these steps:

Plaintext: HELLOPOLLUX
Keyword:   KEYWORD
Padding:   X

Step 1: Normalize and pad plaintext
HELLOPOLLUX → HELLOPOLLUX (padding added if necessary to fill structure)

Step 2: Generate keyed alphabet from keyword
KEYWORD → construct unique letter sequence for substitution

Step 3: Apply positional substitution rules
Map each plaintext letter to ciphertext using current position and keyed alphabet

Ciphertext:
SPPPNOLHZIPP

Each letter’s mapping may vary depending on its position, giving the cipher polyalphabetic characteristics and reducing simple frequency patterns.

Pollux Cipher: Decoding

Decoding reverses the encryption using the same keyword and padding rules. Each ciphertext letter is mapped back to its original plaintext letter according to the keyed alphabet and positional adjustments:

Ciphertext: SPPPNOLHZIPP
Keyword:    KEYWORD
Padding:    X

Step 1: Reconstruct keyed alphabet from keyword
Step 2: Reverse positional substitution for each ciphertext letter

Plaintext:
HELLOPOLLUXX

Padding letters, such as the final X, are preserved unless manually removed. The exact positioning of letters during encoding must be replicated to accurately recover the original message.

Pollux Cipher: Notes

Key characteristics of the Pollux Cipher include:

• Type: Polyalphabetic substitution with positional variation
• Key: Single keyword to generate substitution alphabet
• Padding: Typically X to fill message blocks
• Strengths: Introduces variability for repeated letters, complicating frequency analysis
• Weaknesses: Vulnerable if keyword or positional rules are known

The Pollux Cipher is an illustrative example of classical cipher design, showing how combining substitution with positional manipulation can increase security over simple monoalphabetic ciphers.