Sample interview questions: What measures do you take to ensure the privacy of quantum communications?
Sample answer:
To ensure privacy in quantum communications, several measures are taken. One crucial technique utilized is quantum key distribution (QKD), a method that allows two parties to establish a secure cryptographic key. QKD relies on the principles of quantum mechanics, specifically the inherent uncertainty principle and the no-cloning theorem.
Firstly, QKD employs a quantum channel, usually through the transmission of single photons, to exchange the encryption key between the sender and receiver. Since any measurement or interception of these photons inevitably disrupts their quantum state, any eavesdropping attempts can be detected. This property, known as quantum state collapse, ensures that the communication remains secure.
Additionally, QKD employs various protocols to detect any potential eavesdropping activity. One widely used protocol is the BB84 protocol, which involves the transmission of photons in one of four possible quantum states, representing 0 or 1 in two different bases. The sender and receiver randomly choose bases for each transmission, and afterward, they publicly compare a subset of their key bits. Any discrepancy between their measurement results indicates the presence of an eavesdropper.
To counteract potential attacks, QKD also employs a technique known as information reconciliation. This process allows the sender and receiver to correct any errors or discrepancies that may have occurred … Read full answer