The rail fence cipher uses a number of rails to layout the plaintext characters in a zigzag cipher. With this, the plaintext letters are presented diagonally using an up-down pattern from left to right, and where the message can then be read row-by-row from top to down. In this case, we will reverse the rail code to give the plaintext.
CTF: Railfence Cipher (Decode) |
Rail Fence Code
'WEAREDISCOVEREDFLEEATONCE', gives: W . . . E . . . C . . . R . . . L . . . T . . . E . E . R . D . S . O . E . E . F . E . A . O . C . . . A . . . I . . . V . . . D . . . E . . . N . .to give:
WECRLTEERDSOEEFEAOCAIVDEN