How encryption holds our digital society together

Encryption is like the steel frame of a building: invisible, but holding everything together. In our digital age, encryption is an absolute necessity, and even if you think you don’t have any skeletons in your closet, there’s still good reason to keep your data secret. friend.

“We all have something to hide and have a good reason to do so. Because information is so valuable, it’s important that we have the opportunity to decide for ourselves who can see it. believe we own. Encryption helps us do this,” said Assistant Professor Tyge Tiessen from DTU Computing.

You often say that if you don’t encrypt your communications, it’s the equivalent of sending an open postcard, where everyone involved in the processing of the message can read it. In turn, if you encrypt your message, it’s like a sealed envelope that only the recipient can read once opened.

“Much of our communication is based on encryption, so without it we’d be thrown back to the digital Middle Ages,” said Tyge Tiessen.

You will have to pay cash everywhere, have to visit Citizen Services to change your address, cannot shop at Nemlig.com or other online stores, and unauthorized people will your email is easy to read. In short, our entire daily digital life will slowly fall apart.

electromechanical coding

Today, most encode done digitally with lots of zeros and ones, but coding was more difficult in the past. The most famous cipher machine in history is probably the Enigma, which the Germans used to send secret messages during the Second World War, and which was encrypted by electromechanical alterations each letter typed on. machine into another letter. It is believed that there are only about 300 copies of the Enigma machine left in the world, and DTU has one of them.

Enigma used propellers that rotate when one of the machine’s keys is pressed and through a electrical circuit, changed one letter to another, then lit up on the Enigma machine. By knowing the starting setting of the rotor, the receiver can easily decode the message.

Tyge Tiessen said: “Mystery is not a unique way of encryption, there are other similar encryption devices, but the way it is broken is of great importance to us.

The British team led by Alan Turing, who cracked the Mystery, developed a particular machine called The Bombe, which automatically broke codes, allowing the British to decode nearly all encrypted messages. Germanization at the end of World War II. It is believed to have shortened World War II by two years and saved millions of lives, and Turing’s work laid the foundation for modern computers.

“It gave us a completely different understanding of how encryption attacks work,” said Christian Majenz, assistant professor of cryptography at DTU Compute.

“Modern cryptography is both easier and more complex. It’s much harder to crack than Enigma but at the same time very easy to do on a computer.”

Many non-military enemies today

In the past, encryption was mainly used by the military, but today, encryption has reached every corner of society and this poses challenges.

Tyge Tiessen said: “There are more enemies today because we use cryptography in many contexts. The enemy could be your neighbor who discovered that your network was not secure and then hacked it. that network to discover what you’re doing”.

Therefore, everyone from private companies to public authorities, banks, utility companies and individual need encryption as a bulwark against hackers. And perhaps even against Smart service—as the revelations of whistleblower Edward Snowden have shown, even law-abiding citizens are at risk of being tracked, and so communications services have begun to use encryption that mostly cannot be tracked.

Quantum computers change everything

However, in the future, all our encryption may be broken when we have quantum computers that can solve complex problems that even the fastest supercomputers can’t succeed in. It’s a ticking bomb in our digital society.

“This is the transition to anti-quantum encryption,” said Assistant Professor Christian Majenz, who conducts research on precision quantum encryption at DTU Compute.

“We’re trying to develop cryptography before quantum computers come along, because otherwise they could be used to access all of our existing data. But once we figured it out we figured it out. anti-quantum algorithms, it’s like a Lego brick that you can build on.”