Audience: Elementary and Middle School Students
Did you know? Encryption has been around since ancient times and dates back to Ancient Sparta, where a device called a scytale was used to send secret messages. Photo by Markus Spiske from Unsplash.
Swiping past tiny, vibrantly-colored apps, you navigate to your messaging app, and open a conversation with your friend. You quickly tap out a message, add some cheerful emojis, and hit the green send button without hesitating. A second later, your friend responds, and you carry on texting for an hour. In that time, you never once think about how your data is protected. How does the messaging app make sure your personal information isn’t shared with any hackers while you’re texting a friend? The answer is simple: encryption.
Encryption brings to mind the image of secret agents cloaked in black, huddling over pieces of paper that divulge nothing but scrambled jumbles of letters. In reality, encryption does not differ from that mental picture too much; it is the process of data being translated into a secret code. It plays a huge role in protecting your data online. While the encryption technology of today is very complicated and very secure, it was once quite simple. One of the earliest instances of encryption was the famous Roman emperor Julius Caesar’s Caesar cipher. You’ve probably used it yourself; it simply involves taking a specific number and shifting all the letters in the message by that number. For example, “HELLO” shifted by two would become “JGNNQ”. This is very easy to crack, even for a human, because all you have to do is run through all the 26 possibilities.
Later, this cipher evolved to become slightly more complicated. Instead of all of the letters in a message being shifted by the same number, letters were shifted by different numbers, in a pattern that repeated. For example, let’s take the same message, “HELLO”, and the shift pattern “1, 2, 3”. H would shift by 1, E by 2, L by 3, and so on. Once the string of numbers ended, it would repeat again for the next batch of letters. This type of encryption happened on a larger scale, and messages were encoded with a 10-bit key. The key refers to the string of numbers, the solution to solving the secret code, if you will.
Now, you may be thinking that a 10-bit key would be a very tough code to crack. And you would be right – it would be quite tedious for a human to perform this task. However, a computer, which can execute calculations very quickly, could find the message in a matter of seconds. Keeping this in mind, experts developed a much more secure code, the one that is used to safeguard your data today. They developed the 256-bit key; an extremely long key that would require the computer to do 2256 (
115792089237316195423570985008687907853269984665640564039457584007913129639936, or 115 quattuorvigintillion) calculations in order to crack the code. That would take forever – literally.
We’re not done yet, though. It gets more complex than that. The two main encryption algorithms are symmetric and asymmetric encryption. Symmetric encryption is the less secure and cheaper of the two; therefore, it is often used for encrypting databases and large amounts of data. Asymmetric encryption is the star when it comes to encryption of private communication, such as texts, for instance.
Think of it like this: two people, A and C, are trying to send a message to each other. While they are corresponding, a third party – you can think of them as a hacker – is trying to access their data. All parties have access to a public key: essentially, a key that is visible to everyone, as the name suggests. We’ll call that key b. However, A and C each have their own private keys as well, which are visible to only them. For simplicity’s sake, A’s key will be called a, and C’s key will be called c. Their correspondence progresses in the following order:
First, A mixes their public and private keys to get ab, which they send to C. A now has b and ab. Along the way, the hacker intercepts ab, meaning they have access to ab and b.
Simultaneously, C mixes their own public and private keys to get ac. They send it to A and are now left with bc and b. The hacker also intercepts this correspondence and now has ab, bc, and b.
A combines C’s message (bc) with their private key, a, to get abc.
C does the same, combining ab with c to get abc. A and C have managed to reach the same solution!
The hacker is left with ab, bc, and b, but has no idea what to do with any of them. If A and C have the capability to multiply numbers, the hacker is a calculator that only has the buttons to add and subtract. They come up with nothing.
The beauty of encryption is evident with this simple yet brilliant solution.
Communication using asymmetric encryption. Graphic created by Nithya Karambakkam.
If you read the news, you might keep hearing about the increasing power of computers; AI, biomedical technology, robotics — tech just keeps getting more advanced every day. Cryptography is no exception. Computers keep computing numbers faster and faster, so in a couple hundred of years, the 256-bit key will no longer be enough to safeguard our data. We will need to use bigger keys, such as 512-bit keys. While they are thought to be a bit overkill in current times, they will become necessary in the future. Other advanced methods of encryption, such as quantum cryptography (transmitting data using photons of light), will become vital as well.
Encryption is very important. That fact cannot be stressed enough. It keeps us safe now, and we need to keep developing it so that it will continue to keep us safe in the future. Now when you text your friend again, you understand the lightning-quick tasks that happen in the second that it takes to send the text. What if encryption didn’t exist? Your data – and you – would be completely and totally vulnerable to hackers.
Bibliography:
Google. “What Is Encryption and How Does It Work?” Google Cloud, 2022, cloud.google.com/learn/what-is-encryption. Accessed 2 May 2024.
Rouse, Margaret. “What Is 256-Bit Encryption? - Definition from Techopedia.” Techopedia.com, 29 Sept. 2023,
www.techopedia.com/definition/29703/256-bit-encryption. Accessed 2 May 2024.
Scherer, Abby. “The Future of Encryption.” Reverus, 18 Feb. 2019, reverus.com/the-future-of-encryption/. Accessed 2 May 2024.
Smirnoff, Peter, and Dawn M. Turner. “Symmetric Key Encryption - Why, Where and How It’s Used in Banking.” Cryptomathic, 3 Jan. 2020, www.cryptomathic.com/news-events/blog/symmetric-key-encryption-why-where-and-how-its-used-in-banking. Accessed 2 May 2024.
Thales Group. “A Brief History of Encryption | Thales Group.” Www.thalesgroup.com, 18 Apr. 2016, www.thalesgroup.com/en/markets/digital-identity-and-security/magazine/brief-history-encryption. Accessed 2 May 2024.
Schneider, Josh, and Ian Smalley. “What Is Quantum Cryptography? | IBM.”
www.ibm.com, 1 Dec. 2023, www.ibm.com/topics/quantum-cryptography. Accessed 14 May 2024.
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