One Cracked Key and Every Bank Site Looks Real | Konstantinos Karagiannis, Protiviti (Ep. 17)

Send us Fan Mail Blond & Quantum Episode 17: One cracked key and every bank site looks real — why "harvest now, forge later" may come first | Konstantinos Karagiannis, Senior Director of Quantum Computing Services at Protiviti Everyone worries that a quantum computer will one day read our encrypted messages. Konstantinos Karagiannis thinks the first real attack will look very different. If an early machine needs about five days to crack a single key, that's roughly 73 attacks a year. Would you spend them reading old emails? Or crack one hardware maker's signing key and push malware every laptop trusts — or a certificate authority's, and make a fake bank site look perfectly real? Konstantinos leads quantum computing services at Protiviti and hosts The Post-Quantum World, which he believes is the longest continuously running quantum podcast. He has spoken at DEF CON on everything from attacking Ethereum smart contracts to "Post-Quantum Panic," the talk that went viral and became his upcoming Wiley book of the same name. Listen to find out: 📍 How the qubits needed to break RSA-2048 fell from about a billion to around 100,000 — and why the floor may be lower still 📍 The "crisscross" that defines Q-Day: falling qubit requirements meeting rising hardware roadmaps 📍 Harvest now, forge later: why forged signatures, not decrypted messages, may be the first quantum attack 📍 Why he sees 2029 as the first year a cryptographically relevant quantum computer is possible 📍 What he finds inside real organizations: hard-coded keys, undocumented root CAs and hardware that will have to be ripped and replaced 📍 How quantum could hit Bitcoin, and why he believes the market wouldn't survive a proven attack 📍 Where AI already helps (cryptographic discovery, AlphaQubit) and where it gets dangerous (compliance attestations no human can audit) 📍 What companies should do now: crypto agility, PQC readiness and quantum-inspired tensor networks Why it matters: every organization will have to migrate to post-quantum cryptography, and most haven't started. Konstantinos's point is that the quantum threat isn't only about secrets being read years from now. It's about trust itself being forged. Guest: Konstantinos Karagiannis is Senior Director of Quantum Computing Services at Protiviti, where he helps organizations prepare for post-quantum cryptography and explore quantum use cases. He studied at Polytechnic in Brooklyn, spent years in cryptography and financial-systems security research, gave his first keynote on quantum key distribution in 2012, and hosts The Post-Quantum World. His book Post-Quantum Panic is due from Wiley on World Quantum Day, April 14, 2027. Blond & Quantum is hosted by Eva Galant. Each episode features a leader from the quantum ecosystem — researchers, founders, and investors — for a laid-back conversation about how quantum technology is shaping the world without the equations. New episodes drop regularly. Subscribe wherever you get your podcasts. Watch on YouTube: https://youtu.be/CA-UwAkUuyY Support the show