The Ultimate Limits of Privacy

By Maria Violaris

Can you keep a secret? Artur Ekert's talk began in the Ancient world, where the notion of sending messages via written communication was first conceived. He led us through the winding roads of time via Caesar ciphers, the enigma machine, public and private keys all the way to the role of quantum mechanics in giving us the ultimate security allowed within the laws of physics. 

Remarkably, the discovery of quantum cryptography means that there is a fool-proof way for any "eavesdropping" on a message sent from one place to another to be detected. This holds irrespective of any mathematical progress or advances in quantum computing that allow us to perform operations like the factoring of large numbers more efficiently - which threatens classical cryptographic methods. With this ultimate promise of security, there has been huge interest from industry in creating the technology for quantum cryptography. Today, devices enabling quantum cryptography have even become commercially available.

After Ekert's tour of secrets through time, there was a Q&A session with the audience. Ekert himself made the ground-breaking discovery that quantum cryptography provides ultimate security in his 1991 PhD thesis, and our audience naturally had many questions about his talk, discoveries, life and current research. What those insightful thoughts and entertaining anecdotes were exactly, is our very own QuInSoc quantum secret.