Quantum Computing and Its Implications for Cyber Security


Quantum computing has been a buzzword in the tech industry for some time. It’s a computing innovation that has been gaining traction lately, and will undoubtedly change how we process information.

Quantum computers use quantum bits (or qubits), which can exist in multiple states simultaneously (combination of both 0 and 1) — opposed to conventional computers that use bits (0 or 1) to encode information. This allows them to perform certain computations faster than traditional computers, making them valuable in fields such as cryptography and financial modelling.


Cryptography, one of the cornerstones of cybersecurity, involves the process of encoding message so that only authorised parties can read them. At the moment, encryption replies on mathematical algorithms that are difficult to break, like factoring large numbers into primes.

Thus, deciphering encrypted messages would be impractically time-consuming even with the most powerful computers now in use. However, given that quantum computers have the potential to break these algorithms much more quickly, their potential implications for cybersecurity are significant.

Additionally, quantum computers have the potential to break these mathematical problems much faster using algorithms like Shor’s algorithm.

Shor’s Algorithm

Shor's Algorithm

Shor’s algorithm is a quantum algorithm that can efficiently factor large numbers. With a quantum computer (with enough qubits), it utilises Shor’s algorithm to break modern encryption methods, rendering them useless.

The possibility of quantum computers decrypting data has caused considerable worry in the cybersecurity community. It’s not just a hypothetical risk; researchers have already shown that small-scale quantum computers may be used to break basic encryption. The threat to encryption will only increase as quantum computers develop in strength.

Post-Quantum Cryptography

To counter this issue, researchers are focusing on creating new encryption techniques resistant to quantum computing attacks in order to combat the threat of quantum computers cracking cryptography.

For instance, the post-quantum cryptography utilises algorithms that are still difficult to solve, even with quantum computers. In fact, post-quantum cryptography algorithms are now being evaluated by the National Institute of Standards and Technology (NIST) to determine which ones should be standardised for usage in the future.

In addition to post-quantum cryptography, another promising solution to the threat posed by quantum computing is quantum key distribution (QKD). QKD allows for the creation of a shared key between two parties using the principles of quantum mechanics, making it secure against interception by a third party.

Even if a quantum computer were to crack the encryption used to transmit the key, it would not be able to read the key itself or go undetected, making QKD a promising solution for secure communication in the post-quantum era.


Quantum computing indeed does has the power to transform industries, and cybersecurity is no exception. Yet, the threat of quantum computers cracking encryption is very real.

Nonetheless, researchers are already working towards developing new encryption methods that can withstand quantum attacks. The future of cybersecurity lies in a combination of cutting-edge technology and a relentless pursuit of innovation and research!


  1. Mosca, M. (2018). Cybersecurity in an Era with Quantum Computers: Will We Be Ready? IEEE Security & Privacy.

  2. Gillis, A. S. (2022). Quantum key distribution (QKD). Security.