What is Quantum Computing Threat?

Modern cryptography such as elliptic curve cryptography helps in securing internet payments, banking transactions, emails and even phone conversations. Most of today’s cryptographic algorithms are based on public-key encryption as it is considered to be secure against modern computer attacks. But still, Quantum computing can simply break this security by performing reverse computing of private keys that too faster than a conventional computer.


Although, quantum computers are not so strong yet, it could attack conventional cryptographic algorithms and hence many national governments and organizations have analyzed about the risk involved when this technology becomes a practical reality.

Specially, the Military agencies and leading technology companies have already started developing quantum computers as it can process massive amounts of data in a relatively short amount of time. With the practical and theoretical research, the practical quantum computer may be launched very soon.

Conventional cryptographic systems offer computational security but not really 100% as the strength of  current cryptographic algorithms rely on complex mathematical problems, such as integer factorization and elliptic curve discrete logarithm problem.

These problems can be solved only by using large-scale quantum computers which can easily crack conventional algorithms. As a result, security experts have begun designing new encryption algorithms that are quantum-resistant and can’t be cracked as quickly as conventional algorithms.


Newly, the National Security Agency (NSA) publicly announced their plans for transitioning to quantum resistant algorithms against the quantum computing threat. This action has raised concerns over Public Key Infrastructure (PKI) that is used extensively in securing the World Wide Web.

Quantum computers will be a threat to both symmetric key algorithms and asymmetric public key algorithms as they can break every single popular public key algorithm in a fraction of seconds. Quantum algorithms such as Shor’s algorithm could be used to recover an RSA key to some extend but quantum computers are still to be improved.

Post-quantum cryptography is being used specially for designing cryptographic algorithms that are secure against quantum computers attack. It is estimated that 2048-bit RSA keys could be broken on a quantum computer comprising 4000 qubits and 100 million gates, though few public-key algorithms are still unbreakable.

Quantum cryptography is developed through complex mathematical problems to provide stronger security than traditional one. Therefore, quantum computing as a reality will result in re-engineering and enhancements in current cryptographic systems.

It may take little time for large-scale quantum computers to become a reality but experts are trying their best to figure out cryptographic mechanisms to convert to the new schemes that resist quantum attacks. This transition which is really a tough task should take place soon before our systems become vulnerable to attacks.