Quantum Computing In Cryptography: Myths Vs. Facts

Quantum Computing In Cryptography: An In Depth Guide

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Quantum Computing in Cryptography: Myths Vs. Facts


Quantum computing has emerged as a revolutionary technology with the potential to significantly impact various fields, including cryptography. As quantum computers become more powerful, concerns and misconceptions about their impact on cryptography have also arisen. This article aims to separate myths from facts regarding the role of quantum computing in cryptography. We will explore the myths surrounding quantum computing and address them with factual information and evidence.

Myth 1: Quantum Computers Can Break Any Encryption

  1. Fact: While it’s true that quantum computers have the potential to break many existing cryptographic algorithms, not all encryption methods are vulnerable to quantum attacks.
  2. Fact: Current symmetric key algorithms, such as AES, are considered secure against quantum attacks when used with sufficiently large key sizes.
  3. Fact: Quantum-resistant asymmetric encryption algorithms, like lattice-based or code-based cryptography, have been developed to resist attacks from quantum computers.
  4. Fact: The adoption of new quantum-resistant algorithms is a critical step towards ensuring secure communication in a post-quantum era.
  5. Fact: It is essential for organizations to start implementing quantum-resistant algorithms and transitioning away from vulnerable schemes as a proactive measure.

Myth 2: Quantum Computers Already Exist in a Practical Form

  1. Fact: Quantum computers are still in the early stages of development, and practical, fully functional quantum computers capable of breaking complex encryption are not yet available.
  2. Fact: Despite recent advancements, current quantum computers suffer from error rates and instability, making them unsuitable for real-world applications.
  3. Fact: Researchers continue to work towards overcoming the challenges associated with quantum computing, including error correction and scalability.
  4. Fact: It is anticipated that it may take several more years, possibly even decades, before practical quantum computers with true cryptographic-breaking capabilities become a reality.
  5. Fact: This provides ample time for organizations to develop and implement quantum-resistant cryptography to safeguard their sensitive information.

Myth 3: Quantum Computers Make All Data Vulnerable

  1. Fact: Quantum computers do not automatically render all existing data vulnerable.
  2. Fact: Only data protected by encryption algorithms that are vulnerable to quantum attacks is at risk.
  3. Fact: Legacy data encrypted using vulnerable algorithms can be re-encrypted with quantum-resistant algorithms to ensure long-term security.
  4. Fact: Data at rest encrypted with quantum-resistant algorithms remains secure even if quantum computers become powerful enough to break current encryption methods.
  5. Fact: The main concern lies in protecting data that is in transit, such as communication channels, where encryption methods susceptible to quantum attacks might still be in use.

Myth 4: Quantum Computers Will Make Blockchain Obsolete

  1. Fact: Quantum computers pose a theoretical threat to existing blockchain technologies that rely on vulnerable cryptographic algorithms.
  2. Fact: However, there are ongoing efforts to develop quantum-resistant cryptography for blockchain, ensuring its continued relevance and security in a post-quantum era.
  3. Fact: Cryptographic upgrades, such as the utilization of quantum-resistant signature schemes or new hash functions, can bolster the security of blockchain networks against quantum attacks.
  4. Fact: Blockchain platforms will need to adapt and transition to quantum-resistant cryptography to maintain data integrity and privacy in the future.
  5. Fact: The blockchain community is actively researching and implementing quantum-resistant solutions to mitigate the potential impact of quantum computers.

Myth 5: Quantum Key Distribution Is the Ultimate Solution

  1. Fact: Quantum Key Distribution (QKD) is a cryptographic technique that leverages quantum properties to ensure secure key exchange between parties.
  2. Fact: While QKD offers strong security guarantees, it is not a silver bullet solution for all cryptographic needs.
  3. Fact: QKD requires expensive infrastructure and is initially limited to short distances due to practical constraints.
  4. Fact: Implementing QKD on a large scale is complex and may not be feasible in certain environments.
  5. Fact: Quantum-resistant algorithms and hybrid cryptographic solutions that combine classical algorithms with quantum-resistant techniques provide a more practical and scalable approach.


Understanding the realities of quantum computing in relation to cryptography is crucial in dispelling myths and ensuring effective security measures. While quantum computers have immense potential to impact current cryptographic systems, it is vital to implement quantum-resistant algorithms and technologies to counter these emerging threats. As quantum computing continues to evolve, collaboration, research, and investments in post-quantum cryptography are essential to maintain the integrity, confidentiality, and availability of sensitive information.


  1. nist.gov
  2. ieee.org
  3. quantiki.org
  4. cryptojedi.org
  5. arxiv.org

Quantum Computing In Cryptography: An In Depth Guide