Quantum computers have potential for great advances in our understanding of the world, and it may be happening sooner than we think with recent advances from UNSW in discovering how to control millions of qubits simultaneously (UNSW, 2021). Some of the advances that are predicted to come from quantum computing include: chemical and biological engineering; artificial intelligence; financial services and complex manufacturing (Bova, 2021). These benefits are the main drivers of R&D of quantum computers, it is also predicted that they will be useful for searching very large datasets and solving intractable mathematical problems (Prince, 2014). We may even gain a better understanding of what bees are saying when they dance (Frank, 1997).
We are familiar with conventional computers which operate using bits, which can have a value of either zero or one with transistors being used for tracking and manipulating the bits. Quantum computers operate using qubits, these are made of fundamental particles and can hold three states, a zero, one or a superposition of both, allowing quantum computers perform simultaneous calculations.
As quantum computing is an emerging field, there have not yet been any incidents concerning privacy, but there are privacy concerns. It is predicted that RSA and ECC will be broken within 30 years (Stebila et al., 2010, p. 4), and that quantum computers will solve current encryption algorithms and brute force passwords much faster and break public key cryptography, cracking 2048 bit RSA in eight hours (MIT, 2019)). Due to asymmetric cryptography’s predicted loss of utility, Panda Security, (2017) recommends avoiding encryption based on asymmetric keys such as RSA, EIGamal, or any based on the Diffy-Hellman protocol.
For many of us, the privacy problems are not immediate, the fact that your password will be breakable in 30 years isn’t a real concern, but there are real concerns with China reportedly scraping encrypted data in the hope of cracking it with quantum computers in the future (Tung, 2021). There are also cases, such as governments and health industries, where information secrecy has a greater horizon, of up to 100 years (Stebila et al., 2010, p. 4). Predicted quantum computing capability poses a risk to these secrecy requirements.
These predictions highlight the need for consideration of privacy in the post quantum world. Fortunately quantum cryptography provides privacy enhancing features quantum computers are also capable of encryption, with quantum cryptography with the most well known method being Quantum Key Distribution (Broadbent & Schaffner, 2015, p. 1). Quantum cryptography offer a number of benefits including: everlasting security; eavesdropper detection (Stebila et al., 2010, p. 9); Key-reuse (Broadbent & Schaffner, 2015, p. 5) the ability to estimate the amount of information an eavesdropper has obtained (Stebila et al., 2010, p. 3).
As long as defensive cryptography can advance with offensive cryptography, I think the benefits of quantum computers will outweigh the downsides. As outlined, we stand to greatly increase our ability to understand our world in much finer detail. Ultimately, whether this is a good or bad thing, comes down to what we choose to do with the knowledge.
References
Bova, F. (2021, July 16). Quantum computing is coming. What can it do? Harvard Business Review. https://hbr.org/2021/07/quantum-computing-is-coming-what-can-it-do
Broadbent, A., & Schaffner, C. (2015). Quantum cryptography beyond quantum key distribution. Designs, Codes and Cryptography, 78(1), 351–382. https://doi.org/10.1007/s10623-015-0157-4
Chen, L., Jordan, S., Liu, Y.-K., Moody, D., Peralta, R., Perlner, R., & Smith-Tone, D. (2016). Report on post-quantum cryptography. National Institute of Standards and Technology. http://dx.doi.org/10.6028/nist.ir.8105
Contributors to Wikimedia projects. (2021, October 27). Post-quantum cryptography. Wikipedia. https://en.wikipedia.org/wiki/Post-quantum_cryptography
Devetak, I., & Winter, A. (2004). Relating quantum privacy and quantum coherence: An operational approach. Physical Review Letters, 93(8). https://doi.org/10.1103/physrevlett.93.080501
Frank, A. (1997, November 1). Quantum honeybees. Discover Magazine. https://www.discovermagazine.com/planet-earth/quantum-honeybees
Katwala, A. (2020, March 5). Quantum computing and quantum supremacy, explained. WIRED UK. https://www.wired.co.uk/article/quantum-computing-explained
Mavroeidis, V., Vishi, K., D., M., & Jøsang, A. (2018). The impact of quantum computing on present cryptography. International Journal of Advanced Computer Science and Applications, 9(3). https://doi.org/10.14569/ijacsa.2018.090354
Milmo, D. (2021, November 29). Chinese could hack data for future quantum decryption, report warns. The Guardian. https://www.theguardian.com/technology/2021/nov/29/chinese-could-hack-data-for-future-quantum-decryption-report-warns
