Kyber vs. RSA-2048

Summary

Kyber vs RSA-2048 — Explained Simply (and Why RSA Is Already Dead) You’ve probably heard that “quantum computers will break the internet.” Most people nod, file it under “future problems,” and keep uploading files to Google Drive. This article is here to ruin that comfort. The One-Sentence Summary RSA-2048 and all elliptic-curve cryptography (ECC) die the day a large enough quantum computer runs Shor’s algorithm. Kyber (now officially ML-KEM) does not — and is already standardized, fast, and shipping today. That’s it. Everything else is details. But let’s go through those details — slowly, clearly, and without the PhD jargon. 1. How RSA Actually Works (in plain English) RSA is built on one brutally hard math problem: “If I multiply two huge prime numbers together, it’s basically impossible to figure out what the original two primes were.” Example (with tiny numbers you can actually calculate): Alice picks two primes: 3 and 11 Multiplies them → public key = 33 Anyone can send her a message using 33 Only Alice, who knows the original 3 × 11 split, can decrypt In real life those primes are ~2,048 bits each. The public key is a giant number with over 600 digits. Factoring that number back into its original primes with a normal computer would take longer than the age of the universe. That’s why RSA has kept your HTTPS connections and cloud logins safe for 30+ years. Want to see what a real RSA-2048 public key looks like? Here’s a Python script that generates one: from cryptography.hazmat.primitives.asymmetric import rsa# Generate an RSA-2048 keypairprivate_key = rsa.generate_private_key(public_key = private_key.public_key()# Extract the modulus (the giant public key number)modulus = public_key.public_numbers().nprint(f"RSA-2048 Public Key Modulus: {modulus}")print(f"That's {len(str(modulus))} digits long!")# Example output (truncated):# RSA-2048 Public Key Modulus: 25195908475657893494027183240048398571429282126204032027777137836043662020707595556264018525880784406918290...