Quantum Key Distribution: Who Said Privacy is Dead?
When Edward Snowden revealed that the NSA secretly cracked the most celebrated and highly trusted ciphers in use today, it was a black day for the ordinary people who wanted to believe in the privacy and confidentiality of their sensitive communication. Indeed all the privacy defense hitherto was built with smart-math, and hence it was being defeated with smarter-math. All the privacy defense hitherto was built on government laws, and hence it was being defeated by government law-breakers.
And that is where quantum cryptography is different. It builds privacy defense not on smart-math that yields to smarter math, but on quantum physics that yields only to post-quantum physics, which has not yet been invented, it will take some time. Quantum cryptography builds its privacy defense not on government laws but on natural laws. Unscrupulous, unethical people in power cannot repeal, nor violate the law of gravity, and they are helpless vis-a-vis the laws that underlie quantum secrecy.
The simplest way to use quantum power to restore our long lost privacy is to allow two online strangers to build mutual privacy by sharing a secret code either through quantum entanglement, or through destructive reading. The computing machines are not so easy to build, it turns out, but they are coming. The principles of quantum key distribution are simple, and elegant. Allow yourself to a mini (10min) course in my Crypto Academy: “Quantum Key Distribution: A Conceptual Primer for Online Privacy Enthusiasts”