Disclaimer: I’m not a cryptography expert. I’m a software engineer who builds things. What I share here comes from my personal research, not deep cryptography expertise.
Think of encryption like securing your valuables. We lock things up because we don’t want strangers looking at our personal stuff or stealing what’s important to us. Just like you wouldn’t leave your wallet on a park bench or your passport on the bus, you don’t want to leave your private information out in the open. There are two main ways we do this:
- Using the same key (like your house key) to lock and unlock something. This is what we call AES encryption.
Advanced Encryption Standard (AES) turns your data into scrambled text using a secret password, and only someone with that same password can unscramble it. Think of it like a special lock on a safe - you need the exact same key to lock and unlock it.
- Using different keys (like a mailbox where anyone can put mail in, but only you can open it). This is what we call RSA and ECC encryption.
RSA (Rivest–Shamir–Adleman) and ECC (Elliptic Curve Cryptography) encryption use two different keys - a public key that anyone can use to encrypt messages (like dropping mail in a mailbox), and a private key that only the owner can use to decrypt them (like having the only key to open the mailbox). This is why they’re called public-key cryptography systems.
Quantum computers are really good at solving certain types of math puzzles. It’s like they have a superpower for finding patterns.
So, what’s the fuss about? Well, the mailbox-style encryption (RSA and ECC) relies on math puzzles which quantum computers could potentially crack using Shor’s algorithm.
Shor’s algorithm is a quantum algorithm for finding the prime factors of an integer.
The house-key style encryption (AES) is different. It doesn’t rely on those same math puzzles. Even with a quantum computer, breaking into AES-encrypted data would be like trying every possible combination on a lock with trillions of trillions of possibilities. Even quantum computers can’t check all those combinations in any reasonable amount of time.
The locks on your front door (AES encryption) are still strong against quantum computers. But the locks on your mailbox (RSA/ECC encryption) might need an upgrade.
Security experts are already working on new mailbox-style locks that even quantum computers can’t break. They’re called “post-quantum” or “quantum-resistant” algorithms. It’s like designing a new kind of mailbox that uses completely different mechanics to stay secure.
Imagine if locksmiths knew that a new tool for breaking certain locks was coming in a few years. That’s where we are with quantum computers. We’re not waiting until the last minute - we’re already building better locks.
What often gets missed
Symmetric encryption algorithms like AES are largely quantum-resistant already. They just need larger key sizes - think of it like adding a few extra pins to an already secure lock. It’s a simple upgrade to something that’s already working well.
Quantum computers are not some magic wand that breaks all encryption. Think of them more like a specialized lock pick - they’re really good at breaking certain types of locks, but completely useless against others.
It’s similar to how a master key might open all the doors in a hotel, but it won’t help you unlock your bike chain or open your garage door. Sure, quantum computers are incredibly powerful at solving certain math problems, but many of our everyday security systems use completely different methods that quantum computers can’t crack.
The headlines about quantum computers ‘breaking encryption’ miss this ESSENTIAL detail. Just because they can potentially crack one type of lock doesn’t mean all our security is doomed. In fact, most of the encryption protecting your daily life is already quantum-proof.