E91 Protocol
IntermediateE91 Protocol is a quantum key distribution method using entangled particle pairs to create a shared secret key, with security guaranteed by the laws of quantum mechanics.
In Plain English
Imagine Alice and Bob each receive one glove from a perfectly correlated pair. To check for an eavesdropper, they publicly compare notes on the orientation of some of their gloves. If an eavesdropper had intercepted and replaced a glove, the perfect 'left-right' correlation would be broken, revealing their presence. E91 uses the correlations in entangled particles this way to detect spying.
Why It Matters for Your Career
Quantum Network Engineer or Security Researcher candidates should understand E91's security proof. Companies like Toshiba, ID Quantique, or Qunnect that focus on quantum communication will expect familiarity with it. In an interview, you may be asked to contrast E91's entanglement-based security with the BB84 protocol.
Related Terms
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