Columnar Transposition Cipher
Encrypt and decrypt messages by writing text into a grid and reading off columns in keyword-sorted order — a pure transposition cipher.
What Does This Tool Do?
The Columnar Transposition cipher writes the message into a grid row by row, then reads off columns in alphabetical order of the keyword. A pure transposition — letter order changes but letters themselves do not.
Key Features
Grid Shown
Visualises the encryption grid with column order.
Keyword Ordering
Columns read in alphabetical order of keyword.
Both Directions
Encrypt and decrypt.
Copy Result
One-click copy.
How to Use
- Enter your message.
- Enter a keyword — its alphabetical order determines the column reading sequence.
- Click Encrypt or Decrypt.
- The grid shows how columns are reordered.
Frequently Asked Questions
How does Columnar Transposition work?▾
Write the message into rows across n columns (n = keyword length). Sort column headers alphabetically. Read off columns in that sorted order to get the ciphertext.
Is it a substitution or transposition cipher?▾
Transposition — the letters remain the same but their positions are rearranged. No letter is replaced by another.
Why are X characters added?▾
The grid is padded with X to fill the last incomplete row, ensuring all columns have the same height during encryption.