Quantum Cryptography - Professor Kurt Langfeld
29th February 2020
Since 4000 BC, sending encrypted messages has been of key importance for the military, but also for the public. In the age of the internet, the need for encryption is growing on a daily basis.
For millennia until WWII, messages were solely encrypted by replacing groups of symbols by others (substitution cipher). Modern applications of encryption raise a very important question: Can you exchange a secret message with a person that you have never met before? The Mathematics for a resounding 'yes!' was only found relatively recently, in the 1970s.
With the beginning of this millennium, a new question has arisen: 'Can you exchange a secret message with a person without encrypting at all?' Quite surprisingly, the answer is 'yes!' again, and, this time, it rises from modern physics: quantum cryptography.
This talk will give a brief overview over the elements of cryptography and quantum physics likewise. With a hands-on experiment, you will then agree on a secure password using quantum cryptography.