RSA is hard because factoring is hard, Quantum computing changes that!

Was reading about some quantum computing concepts today and stumbled upon Shor’s Algorithm and Grover’s Algorithm.

I’ve always been curious about how quantum computing could threaten modern cryptography. Got to know that RSA’s security basically relies on the fact that multiplying two large primes is easy, but finding the original primes from the result is extremely hard. Shor’s Algorithm changes that by making factorization efficient on a quantum computer.

Grover’s Algorithm was interesting too. It’s like making the “needle in a haystack” search faster, which means brute-forcing things like AES keys becomes more practical.

Put together, it’s easy to see why Post-Quantum Cryptography (PQC) has become such a big topic.

Didn’t get time to go deep into either algorithm today, just enough to understand the gist. But it’s fascinating how quantum computing changes what we consider “hard” problems compared to classical computing.

Worth spending more time on this in the future.