Architecture, Network security

Encryption: A brief history of our secret keeping

August 26, 2014

Words like encryption and data security are getting more “buzz” than an army barber this year. From recent customer data security leaks at Snapchat and Target, to businesses like Google and Microsoft changing data protection policies in response to the National Security Agency's (NSA) data-collection practices, encryption -- or its utter failure -- affects all of us now. But this wasn't always the case.

While the history of encryption is long, its widespread use is a fairly recent phenomenon. Only in the last century have governments encrypted communications with much frequency, and public communications were not regularly encrypted until the 1970s. In the wake of encryption's incessant headline grabs in 2014, a look at the practice's transformation through time might prove timely.

While my office wall lacks a PhD in history, as person with interest in encryption both professionally and, let's say, recreationally, I'll offer a quick, pop quiz-free primer on encryption through time.

What we think of as "classic cryptography” – those encoded puzzles people created and worked out by hand – has been in existence for nearly four millennia. While we think of codes, ciphers and encryptions in terms of secrets, or at the very least in terms of privacy, the first known cipher dates to 1900 BC in the Old Kingdom of Egypt and was not necessarily created with secret-keeping in mind. Historians believe that these ciphers were actually created to increase mysticism and not with the intent to hide secrets from other people.

The earliest instances of ciphers suspected of keeping secrets date to 1500 BC in Mesopotamia. Clay tablets were found that hid recipes for pottery glazes and potentially the “Colonel's secret herbs and spices” of the time; can't have unauthorized access to that kind of information.

For the most part, though, encryption was still very rare. This was possibly because so few people could read and write, or because people rarely communicated with those they couldn't meet face-to-face. As such, the evolution of ciphers was slow in development. Around 500 to 600 BC, Hebrew scholars used simple substitution ciphers, much like the ones seen in today's newspaper Cryptogram puzzles. Julius Caesar famously used the Caesar cipher to encrypt messages to his armies. Encryption's sister-discipline, code breaking, began in the medieval Arab world alongside the development of more advanced ciphers and discoveries such as frequency analysis, though these tools were not often put into practice.

It wasn't until the late medieval and early modern era in Europe when political unrest and religious tension proliferated the practical use of ciphers and code breaking. The famous Voynich Manuscript was also produced around this time; to date, no one has publicly cracked the secrets of this text (and whether it's even an authentic text or an elaborate hoax is still up for debate). If it is a cipher, it may be one of the most effective ones of its kind to date. Get to work, Snowden.

Ciphers became much more common into the 19th and 20th century, as long-distance technologies like the telegraph and radio proliferated and governments attempted more covert communications. Famously, World War I British code breakers cracked German communications that both turned the tide in naval battles and aided in deciphering the Zimmermann Telegram, which helped convince the United States to join the war on the side of the British.

Machine-assisted cryptography led to the German Enigma cipher machine, used before and during World War II. However, savvy Polish code breakers had cracked these machines without the Germans' knowledge before the invasion of Poland, and were able to smuggle this information to Great Britain. Those code-breaking capabilities gave Great Britain and their allies an advantage some estimate may have shortened the war by two years.

Still, until the 1970s encryption techniques were primarily used by governments or in activities related to the state. With the advent of the computer, however, both encryption techniques and code breaking have increased in sophistication. Computers and their processing powers are able to more easily deliver features that make codes more secure, including long keys and true randomization.

Today, nearly everything is encrypted. If your data travels through secure Wi-Fi connections or ethernet, if you need a password to access it, it's been encrypted. However, as computers advance they're more capable of cracking encryptions through brute force, guessing at every possible randomized key until they happen on the correct one. Advancements in encryption are accelerating alongside rapid developments in computer technology – it's an ever-escalating game of cat of mouse.

While it feels like encryption is everywhere nowadays, history shows it's a fairly recent phenomenon. As we become more reliant on technology to safeguard everything from our finances to our personal privacy, encryption will only become more important and valuable to us.

Of course, for all the advances in encryption technologies, authentication remains a major factor in data security. If the wrong person gains access to your password or encryption key, even the most unbreakable encryption is powerless to stop them. The history of passwords and watchwords is rich and storied, reaching back into ancient eras. But that's a tale for another time.
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