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Exhibit 12 of 23
Hall 4 · Exhibit 1 1 min

What is Post-Quantum Cryptography?

Clearing myths and understanding quantum-safe math

What it isNew math on normal CPUs — not quantum hardware
Not the same asQuantum cryptography (QKD photons)
Quantum-safe meansBrute force is the only attack left
The catchKeys are far larger — a bandwidth problem

Clearing the Biggest Myth

Post-Quantum Cryptography () does not mean using a quantum computer to encrypt. There are two distinct fields: Quantum Cryptography (hardware — shooting photons for ) and Post-Quantum Cryptography (software — new math algorithms on normal silicon CPUs). is simply an upgrade to existing mathematical libraries.

What Makes Math 'Quantum-Safe'

For an algorithm to be post-quantum, brute force must be the only way to break it, even with a quantum computer. If forced to guess one-by-one, a quantum computer takes billions of years — just like a classical one.

The Goldilocks Problem

A viable algorithm must be: (1) hard for classical computers, (2) hard for quantum computers, and (3) light enough for a smartphone to compute in milliseconds. keys are often tens of thousands of bits vs. 256 bits for — creating real bandwidth challenges.

Key and signature sizes comparedSIZES — LOG SCALEX25519 public key32 Bclassical ECDHEd25519 signature64 BclassicalML-KEM-768 public key1,184 BFIPS 203 · hybridML-KEM-768 ciphertext1,088 BFIPS 203ML-DSA-65 signature3,309 BFIPS 204FALCON-512 signature666 Bcompact lattice sigSLH-DSA-128s signature7,856 BFIPS 205 · hash-basedClassic McEliece PK261,120 Bstatic / archival
Logarithmic scale. The bandwidth jump is the real cost of the migration.

Key Takeaways

  • PQC is software running on normal CPUs — not quantum hardware
  • Quantum-safe means brute force is the only attack, even for a quantum computer
  • PQC keys are much larger than classical keys, creating engineering challenges