Encryption Through the Ages: A History

Jun 3, 2016 · 3 min read

The recent encryption debate featured a cast of high-profile — and markedly modern — characters: Apple. The iPhone. And the FBI.

Smartphones may be 21st-century creations, but encryption itself has a much older pedigree. The act of encoding messages to mask their meaning dates back thousands of years. The need to protect the privacy and strengthen the security of our communications are hardly new concepts.

Encryption has a colorful past. From ancient emperors and mathematicians to the Founding Fathers and tech activists of the ’90s, encryption has always kept interesting company. Here’s a quick look back at encryption through the ages:

45 BC

In ancient Rome, Julius Caesar uses the eponymous “Caesar Cipher” to encode private correspondences with his top generals. It’s one of the earliest-known ciphers. When scrambling messages using a Caesar Cipher, letters are shifted forward or backward within the alphabet. So, with a shift of 1, As become Bs, and Bs become Cs. “Encryption” becomes “Fodszqujpo.”

860 AD

Arab mathematician al-Kindi authors “رسالة في استخراج الكتب المعماة,” or “Manuscript for the Deciphering Cryptographic Messages.”

1546 AD

Encryption is at the center of court intrigue at Queen Elizabeth’s Fotheringhay Castle. Mary Queen of Scots is embroiled in an assassination plot, and corresponds with her accomplices using a cipher.

1780 AD

The encoding of messages during the American Revolution helps the Continental Army to mask their communications — and win independence from the British Empire. Paul Revere’s lantern signals (“one if by land, two if by sea”) function as a basic code. And George Washington, Alexander Hamilton, and other key players use encryption to communicate throughout the Revolution.

1991 AD

In the ’90s, Internet activists fight to ensure strong encryption is allowed in consumer software like Web browsers. These victories and the resulting software help pave the way for billion-dollar industries like online banking and e-commerce. Think PayPal, Etsy, and other major shopping sites.

2014 AD

Apple releases default iPhone encryption. As a result, users’ personal data, from photos and messages to call history, is encrypted. Apple’s decision makes headlines in WIRED, The Washington Post, The Guardian and other top news outlets — and stokes debate between the tech company and law enforcement.

2016 AD

The FBI asks Apple to undermine the security of the iPhone in order to aid an ongoing federal investigation. Apple refuses, noting that doing so would set a dangerous precedent and irreparably harm product and user security.

Learn about other present-day threats to encryption, and how you can make a difference »

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Mozilla Internet Citizen

We believe the Internet is at its best as a global public resource, open and accessible to all. Blogs, videos, lists, essays and more from Mozilla.

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