Cryptography keeps our messages secret, our bank transactions secure, and our data safe from hackers — but there is a threat looming on the horizon. Most cryptographic systems used today are based on computational assumptions that could be resigned to history by quantum computers.

The upshot is that quantum computers of the future could be used to crack cryptographic systems. And what is more, messages sent securely today could be decrypted in the future.

To address this threat, researchers, companies and governments are developing quantum-safe cryptography systems that cannot be cracked by quantum computers.

Our guest in this episode of the Physics World Weekly podcast is Ali El Kaafarani, who is an expert in post-quantum cryptography. He is founder and CEO of PQShield, which spun out of the UK’s University of Oxford and develops quantum-safe cryptography systems for use on chips, in applications, and in the cloud.

He explains why quantum computers pose a threat to today’s cryptographic systems, and what the cryptography community is doing about it.