Sign up
Please tick the below box to proceed
I agree (or if I am under 13 my parent or guardian agrees on my behalf) to the terms and conditions of use and that:
- My test statistics may be published on the site leaderboard against my username
- My teacher(s) can review my test scores
- I can receive feedback on my tests from my teacher(s)
Please tick this box to proceed
Already have an account? Sign in
Preview lessons, content and tests
Computer Science & Programming solved. All in one platform.
1. To trial the platform and take tests, please take a few seconds to SIGN UP and SET UP FREE.2. Searching for something specific? See our text overview of all tests. Scroll right for levels, and lists. 3. Student and Teacher User Guides | Schemes of Work | Real Teacher use Videos |
Join 36000+ teachers and students using TTIO.
Rail Fence Cipher
The rail fence cipher (also called a zigzag cipher) is a form of transposition cipher. It derives its name from the way in which it is encoded.
Method
In the rail fence cipher, the plain text is written downwards and diagonally on successive "rails" of an imaginary fence, then moving up when the bottom rail is reached. When the top rail is reached, the message is written downwards again until the whole plaintext is written out. The message is then read off in rows. For example, if 3 "rails" and the message 'WE ARE DISCOVERED. FLEE AT ONCE' is used, the cipherer writes out:
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 . .
Then reads off to get the ciphertext:
WECRLTEERDSOEEFEAOCAIVDEN
Note that this particular example does NOT use spaces separating the words.