Caesar Box decode
Caesar Box decode, classical cipher, a puzzle not a protection, computed on your device. The X padding the encoder added to reach a perfect square cannot be told from real text and is returned with the plaintext. Expect trailing X characters that were not in the original.
Runs on your device. The file is never uploaded.
Caesar Box decode reads your ciphertext down the columns of a square grid and writes the rows back out as plaintext. One trailing newline is dropped first, and a length that is not a square number is refused before any grid is built. The X characters used to fill that grid come back with your text, since nothing marks them.
Questions
What does this expect?
Text that was written into a square grid and read out by columns. It reads the columns back into rows and returns the result, including any padding that was added to fill the square.
Why is there padding on the end?
Because the encoder had to complete the grid. The padding is ordinary characters, so this tool cannot tell them from your message. Trim the tail yourself.
Why does my output look wrong in the middle?
Check that the text length is what the encoder produced. A box decode depends on the exact character count; adding or losing one character shifts every column and turns the output into a different permutation.
Is there a key?
No. The dimensions follow from the length of the text, which is why this offers no protection at all. It is a puzzle format.