Rail fence cipher online

How does the Rail fence cipher work?

What is this method?

Arranges the message in a zigzag across several rails and reads it row by row.

How does it work step by step?

Write the text in a zigzag across the selected number of rails, then concatenate the rails from top to bottom. To decrypt, reconstruct the zigzag path before filling it with ciphertext letters.

Example and practical use

Choose three rails: the message runs down and up in a zigzag, and the ciphertext is formed by reading the rows in order.

How to use the tool

Choose encryption or decryption, enter a message and set the parameters required by the Rail fence cipher. The result is calculated locally in your browser and can be copied or shared without sending the text to a server.

History of the cipher

Simple zigzag transpositions were used as convenient field ciphers in the nineteenth century. They needed no complex equipment—only paper and an agreed number of rails.

Security and limitations

This tool is educational. Classical ciphers can usually be broken with frequency analysis, repetition patterns or a small search through possible keys, so they should not protect confidential information.