Cipher Workshop

Explore six historical ciphers that shaped cryptography from ancient Hebrew scribes to Renaissance courts to the telegraph age. All six run simultaneously so you can compare outputs side by side.

The Ciphers

• Caesar Cipher (44 BCE) — Julius Caesar’s own cipher. Each letter shifts N positions through the alphabet. He famously used shift 3: A→D, B→E, Z→C. Simple but effective when your enemies were illiterate.
• ROT13 (1982) — A Caesar cipher with a fixed shift of 13. Because the alphabet has 26 letters, encoding and decoding are the same operation. Born on Usenet to hide spoilers and punchlines.
• Atbash (~600 BCE) — A Hebrew cipher where the alphabet is reversed: A↔Z, B↔Y, C↔X. Used in the Book of Jeremiah. Also self-inverse — applying it twice returns the original.
• Vigenère Cipher (1553) — Invented by Giovan Bellaso and misattributed to Blaise de Vigenère for centuries. Uses a repeating keyword to shift each letter by a different amount — making frequency analysis far harder. Called “le chiffre indéchiffrable” (the undecipherable cipher) for 300 years until Charles Babbage cracked it in 1854.
• Morse Code (1837) — Samuel Morse’s dot-and-dash encoding for telegraph transmission. Words are separated by / in encoded form.
• Bacon’s Cipher (1605) — Francis Bacon’s binary steganography scheme. Each letter maps to a 5-character sequence of As and Bs (representing 0s and 1s). Originally used to hide secret messages in two typefaces — the world’s first use of binary encoding for communication.