Examkin

Question

Difficulty: HardInformation Technology and Cybersecurity

Consider the following statements regarding Quantum Key Distribution (QKD) and modern cryptographic mechanisms:

1. Quantum Key Distribution uses the principles of quantum mechanics to securely establish a shared secret key between two communicating parties rather than directly transmitting the encrypted secret payload over the quantum channel.
2. In QKD systems, any interception or measurement attempt by an eavesdropper alters the quantum state of the photons, immediately revealing the presence of intrusion to the communicating parties.
3. Post-Quantum Cryptography (PQC) refers to cryptographic protocols that require quantum hardware and quantum entanglement to execute encryption on classical computing systems.

Which of the statements given above is/are correct?

  1. 1 and 2 onlyAnswer
  2. B
    2 and 3 only
  3. C
    1 and 3 only
  4. D
    1, 2, and 3

Answer

1 and 2 only
The option stating '1 and 2 only' is correct. Quantum Key Distribution relies on quantum optics to generate and distribute random symmetric keys, and any eavesdropping attempt perturbs photon states, alerting users to security breaches. Conversely, Post-Quantum Cryptography consists of software-based classical mathematical algorithms intended to run on conventional hardware to resist attacks from quantum computers, making the third statement false.

Step-by-Step Solution

1
Analyze Statement 1 regarding QKD payload transmission
Statement 1 is correct. QKD is a key-establishment mechanism that uses quantum communications to securely distribute random key streams; the actual message payload is encrypted and sent separately over traditional classical communication channels using symmetric encryption.
QKD channels are optimized for photon state transfer to exchange cryptographic key material, not for high-volume data payload transport.
2
Analyze Statement 2 regarding eavesdropping detection in QKD
Statement 2 is correct. Based on fundamental quantum physics principles such as the Heisenberg Uncertainty Principle and the No-Cloning Theorem, measuring or eavesdropping on polarized photon states disturbs the quantum state, introducing detectable error rates (Quantum Bit Error Rate) that alert legitimate parties.
Quantum states cannot be observed or measured without altering their superposition states.
3
Analyze Statement 3 regarding Post-Quantum Cryptography (PQC)
Statement 3 is incorrect. Post-Quantum Cryptography (PQC) refers to mathematical algorithms (such as lattice-based or hash-based cryptography) designed to run on standard classical computers while remaining secure against breaking attacks by future quantum computers (e.g., Shor's algorithm). It does not require quantum hardware or quantum entanglement.
PQC relies on complex classical mathematical problems hard for both classical and quantum systems, whereas QKD requires specialized quantum hardware links.

Key Concept

Quantum Key Distribution vs. Post-Quantum Cryptography
Rate this question

Topics

Information Technology and Cybersecurity

More questions from this topic