Quantum Cryptography
Quantum mechanics started in 1905 when Albert Einstein published his famous paper on the photoelectric effect.
- one outcome of the paper was what some physicists called the “spooky side effects” of a universe made up of indivisible, small quanta or packet of force
- behaved as if they were waves
- two side effects are at the heart of quantum computing
- first side effect is called the observer effect
- means that many of the properties of a quantum (i.e. position, velocity, spin, etc.) cannot be known unless observed
- since observation is a kind of interaction, your observation changes the state of the quantum
- prior to observing such a quantum, or a system of quanta, its state is defined as being a set of probable outcomes all superimposed on each other
- observing the system collapses all of those probabilities into the current result
- quantum computing looks to have each of those probable outcomes be the outcome of a branch in a calculation
- reading out that qubit (quantum bit) forces it to collapse into one result
- provides significant reductions in run time for massively parallel algorithms
- could give advantage both in computing new public and private keys, performing encryption and decryption, and in attacks
- second side effect is entanglement
- two particles created together are entangled, which means if you move one of them someplace else and then observe it, both it and its entangle twin will instantly take on the same state
- happens without any known message, energy, or force traveling the distance between the entangled twins
- proves that an entangled quantum communications link is a tamper-proof way to ensure no one has observed the content of your message or file once encrypted
- two particles created together are entangled, which means if you move one of them someplace else and then observe it, both it and its entangle twin will instantly take on the same state
- Quantum key distribution is the only use of these side effects in practical cryptologic systems, so far
- generate large quantifies of entangled particle pairs that are stored in some fashion and used as a keystream or one-time pad
- any attempts to interrogate the stored copy of the keystream would invalidate it