Skip to content

Decode a Vigenère cipher

Recover a classical polyalphabetic-cipher message with a known key.

Install in Serialize

What it can do

  • Apply a repeating alphabetic key
  • Reverse Vigenère shifts
  • Preserve a reproducible key setting

How the recipe works

Vigenère Decode

Subtract the repeated key shifts from the ciphertext letters.

Demonstration

Sample input

LXFOPVEFRNHR

Expected result

ATTACKATDAWN

When to use it

  • Cryptography classes
  • Puzzle solving
  • Comparing classical and modern encryption

Adapt it

Change the key to the one supplied with your exercise; this operation is not a modern secure cipher.

Source and verification

Adapted from University of Oviedo: Cryptography Applications lab. The explanation and sample are written for Serialize, use synthetic or documentation-safe data, and are checked against the current operation catalogue. The workflow runs locally without an external API call.

Navigation

Type to search…

↑↓ navigate↵ selectEsc close