Cryptography had been around even before computing emerged as a field. The necessity to protect information had been around as early as Caesar’s time. Now every mono alphabetic substitution cipher is referred to as a Caesar’s cipher. The war between cryptanalysts and cryptographers had been long and frustrating. During the second world war, cryptanalysts raced against time to crack the Enigma while cryptographers succeeded with a very strong and provably secure encryption, the one-time pads.
Decades ago, mathematicians introduced a new breakthrough in cryptography: one-way functions which lead to Public-key Cryptography. At the time RSA was proposed, it would take a millennium to break an192bit encryption by brute force. Decades later, cryptanalysts proved with todays computing power, it would now take only eight months.
With today’s advancement, an encryption breakable within 8 months is a critical problem. There are always documents that should be kept safe in the next 10, 20 or even a hundred years. There are weapons being developed by governments whose blue prints should be kept secret for a very long time to keep others from knowing of its existence.
And so the war between cryptographers and cryptanalysts is now on a critical phase. 2 decades ago, theoretical and experimental physicists joined the war equipped with quantum mechanics. With quantum computers, it promises cryptanalysts to be able to break today’s most powerful Public-key Encryptions. But what quantum mechanics breaks with one hand it helps protect with another. With quantum cryptography, it promises provably secure encryptions. With quantum cryptography, it promises cryptographers the power of one-time pads without the having to worry about key distribution problems.
Geneva is using Quantum Cryptography for online voting. And efforts at Europe and Los Alamos are underway to strengthen implementations of Quantum Cryptography. The question is, will Quantum Cryptography implementations be a as unbreakable as promised by it’s theoretical security?