2.7 ARE SINGLE QDs GOOD FOR ANYTHING?
Our daily life depends more and more on secure data communication. Increasingly
complex cryptographic techniques are developed using elegant mathematical
methods based on powerful computers. At the same time, the advancement in
computational power threatens even the most complex codes and allows them to
be broken [27]. An important shortcoming of conventional data communication is
the possibility of undetected eavesdropping. A way out of this dilemma is based on
combining basic principles of quantum mechanics with most modern information
theory. In 1984, Bennett and Brassard first introduced a quantum communication
scheme (BB84 protocol) proposing a secure way to transmit crypto-keys. In July
2004, the “Quantum ...