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Quantum Cryptography
Quantum physics provides a method of achieving an absolutely secure information exchange that is guaranteed to be future proof. Quantum cryptography, or specifically Quantum Key Distribution (QKD) yields a cryptosystem in which:
- A truly random cryptographic key is generated and used for encryption only once (One Time Pad), guaranteeing the encrypted data to be secure - today and forever
- Any attempt to intercept the exchange of the key causes detectable variations in the quantum states carrying the cryptographic key, alerting both sender and receiver to the attack and allowing them to take mitigating action.
- Absolutely secure, one-time-pad key delivery is no longer dependent on human couriers.
First Generation QKD
First Generation QKD is based on "single photon" technology, which requires complex and expensive equipment to generate and detect single photons (particles) of light.
Underlying Principles
- Transmit a one-time pad (key) using single photons
- This transmission is untappable as any attempt at eavesdropping results in detectable variations in the quantum states of the photons, thereby revealing the eavesdropper
- The key is based true randomness drawn from nature
Despite the ability to generate secure keys, single-photon based systems have some considerable disadvantages, these include:
- The need for single photon emitters as well as detectors capable of counting these photons arriving at the destination. Such equipment is highly specialized and expensive, with costs in the order of tens of thousands dollars apiece.
- These systems are also delicate as they employ highly sensitive equipment which can be costly to maintain. In fact, the detectors used are so sensitive that even in a dark room, opening them up would saturate the sensors and destroy the device.
- The responsiveness of this type of system is slow, yielding secret key rates typically below 100kbps. Given the volumes of data transmitted over information networks today, such key generation rates are usually insufficient to allow true OTP encryption. As a result, first generation QKD technology is generally used in a hybrid configuration - in conjunction with classical encryption - to provide enhanced security, but does not yield a truly future-proof system.
Second Generation QKD
QuintessenceLabs is a world leader in second generation QKD, which makes use of continuous variable bright laser beams instead of sending and detecting individual photons.