Security: Best Before 2026

Why the world desperately needs QKD

April 2026 · 9 min read · QKD, nonfiction, take this VERY seriously

It is increasingly accepted we are in an age of dwindling privacy, but few realize how much worse this will get. Our entire information society is built with an unintended skeleton key: a backdoor for anyone with a quantum computer to circumvent all security. With these devices years away, this may seem like a distant risk. However, any communications right now can easily be stored and later decrypted once the technology arrives. Luckily, a solution exists: quantum communication. While current encryption relies on assumptions quantum computers will soon invalidate, quantum communication uses fundamental physical laws to keep information provably hidden regardless of technological progress. Engineering challenges exist but can be solved with a space-based CubeSat constellation that is not just possible but urgent. The longer we wait, the more secrets are irreversibly lost in the approach of a potentially trillion-dollar catastrophe.

The modern information age is built upon the assumption that private communications can be read just by the sender and receiver, making possible everything from online banking to confidential military channels. But information does not teleport magically between devices. It travels publicly via electromagnetic waves or fiber networks that can be trivially intercepted without a trace. Cryptography prevents this, built on a result proved by scientist Claude Shannon in 1949: two people can communicate with perfect secrecy if they share a private key to encode messages, ensuring that any interceptor receives no additional information than random guesses.1

However, this creates a sort of chicken and egg problem, where two people can privately communicate with a shared key, but to have this shared key they must first privately communicate it. RSA and ECC, the encryption algorithms currently used, solve this with one-way mathematical functions: calculations easy to perform but computationally impossible to reverse. For RSA, multiplying large prime numbers is easy, but factoring them back would require trillions of years with large enough numbers. With this, one party can publicly broadcast a key that enables anyone to encrypt messages only they can unlock, allowing a shared private key to be established. All web traffic, online shopping, emails, messages, or digital banks use RSA, ECC and secret keys to stop passwords or bank info from being silently stolen.

Yet in 1994, as early web browsers were taking off, a mathematician Peter Shor proved a fatal weakness in these one-way functions.2 While the calculations in RSA and ECC would take around 300 trillion years for a normal computer to reverse-engineer, in certain conditions they could be undone in just eight hours. The catch was they required something seemingly impossible: a fault-tolerant quantum computer with billions of qubits. In 1994, such a device was science fiction. Top IBM physicist Rolf Landauer argued it was a speculative technology, existing only in equations and nothing more.3 And so the world moved on. The internet grew rapidly, from 3000 websites to 1 billion in 20144 and was soon in everyone’s pockets. All while encryption pervaded into everything—every text message, medical record, bank transfer, classified military record built in defiance of a hypothetical time bomb speculated by a lone mathematician in 1994.

But we aren’t in 1994 anymore. In December 2024, Google announced the Willow chip—a quantum device capable of solving certain problems in five minutes that would take classical supercomputers ten septillion years.5 While it faced criticisms of only being tested on unrealistic problems to exaggerate capabilities, it is only one of many companies aggressively scaling quantum computing capabilities. The elusive quantum computer no longer lives just in equations, but an industry estimated to reach $20.2 billion USD by 2030.6 At the same time, predictions for the number of qubits needed for Shor’s cryptography-killing algorithm dropped from 1 billion in 2015 to 20 million in 2019,7 then from 100,000 to 10,000 within a single month this year.89 By 2030, several companies claim they will have the devices that break open our world. Even with delays, any information sent now can be intercepted and stored until they finally do emerge—every secret currently in the world is on a countdown to Q-Day.

The obvious response to this is to try and find new equations like RSA and ECC that quantum computers can’t break. This is called post quantum cryptography and is what most people are scrambling to implement today. The most popular algorithms utilize lattice-based mathematical structures for which no currently known algorithms exist. The key words there are “currently known”. On July 5 2022, an algorithm called SIKE invented in 2011 and tested for over a decade by cryptography professionals entered the fourth round of the post quantum cryptography competition.10 It was described by the US government as “an attractive candidate for standardization because of its small key and ciphertext sizes.” Just 25 days later, two Belgium researchers released a paper describing how an unrelated 25 year-old math theorem allowed them to break it with only a simple laptop running for an hour.11 The specific methods industry and government are transitioning to don’t have currently known backdoors, but neither did RSA, ECC or SIKE until suddenly they did. While other methods promise greater security, they require keys as long as a short novel just to say “hello”. Even these more conservative bets are still just that: bets, made more confidently from decades more without being broken, but not provably impervious to attacks. The world’s information is one hell of a bet to take.

Luckily, it isn’t one we have to take. A fundamentally different and under-explored type of encryption exists—quantum communication. Rather than relying on unprovable assumptions about our computational limits, quantum communication replaces these shaky foundations with the inherent and unbreakable laws of quantum mechanics. Targeting RSA and ECC’s similar task of sharing a private key, quantum key distribution (QKD) sends information encoded in individual photons (particles of visible light) that collapse when being intercepted. The no-cloning theorem means that the quantum information in such a photon cannot be copied, but an interceptor Eve must guess at its state to measure it, unavoidably disrupting the channel. As a result, QKD gives a physically unbreakable guarantee that, if the error rate is low enough, the shared key is unquestionably private, reviving Shannon’s dream of perfect secrecy.

But if QKD solves all these problems, where is it? The problem is that Google can update to lattice-based encryption with just a software update, but QKD requires new physical infrastructure—a combination of fiber optics and satellites that is yet to scale commercially. Because of the engineering challenges, the US government is currently discouraging the use of QKD in favor of the quicker fix offered by PQC. But this is a mistake.

While investing in QKD is more expensive upfront, current cybercrime already costs the world $9 trillion annually.12 And this is before quantum computers destroy encryption. With frontier AI models finding thousands of decade-old critical bugs in every major operating system just last week,13 it is only a matter of time before a SIKE-style vulnerability is found in PQC. Current financial assets protected by digital encryption totalled $410 trillion USD in 2023 (almost all of which hasn’t even yet transitioned to PQC!)14 The value of information protected is harder to quantify. This doesn’t mean Q-day triggers a single hundred trillion dollar heist—but it does mean years of widening windows of attack on the systems securing the entire digital economy. Next to that, a single satellite constellation is a rounding error.

And this rounding error is becoming ever-more manageable. Fiber-optic quantum networks are limited to hundreds of kilometers. Space solves this, as China’s Micius satellite achieved with a 1,200km link in 2017.15 While this was an expensive one-time demonstration, the complex pointing technology driving costs has since been superseded by new incredibly precise MEMS fine-steering mirrors. Combined with photonic chips developing in Germany, newer satellites could transition: from a hurtling contraption of spinning mirrors the size of a fridge to just two chips in a box you could hold in one hand. In a moment when SpaceX has reduced launch costs 20-fold since 2010,16 with another 10-20x projected within the decade,17 the time is right to scale these demonstrations to a constellation.

We need QKD now. Not tomorrow, or in five years, but now. Yet China is the only country to have demonstrated it in space. A scatter of other countries have preliminary designs or tests. The US doesn’t even have a plan. For a technology this vital to national security, that gap is an Achilles heel we cannot afford. The question is not when to build a quantum internet, but whether it repairs a worldwide security catastrophe or averts one.

Footnotes

  1. Shannon, C. E. (1949). Communication theory of secrecy systems. Bell System Technical Journal, 28(4), 656–715. https://doi.org/10.1002/j.1538-7305.1949.tb00928.x ↩

  2. Shor, P. W. (1997). Polynomial-time algorithms for prime factorization and discrete logarithms on a quantum computer. SIAM Journal on Computing, 26(5), 1484–1509. https://doi.org/10.1137/S0097539795293172 ↩

  3. Landauer, R. (1995). Is quantum mechanics useful? Philosophical Transactions of the Royal Society A, 353(1703), 367–376. ↩

  4. World Economic Forum. (2021, August 6). How many websites are there in the world? https://www.weforum.org/stories/2021/08/number-websites-2021-world-wide-web/ ↩

  5. Google Quantum AI. (2024, December 9). Meet Willow, our state-of-the-art quantum chip. https://blog.google/technology/research/google-willow-quantum-chip/ ↩

  6. MarketsandMarkets. (2025, September 11). Quantum computing market worth $20.20 billion by 2030. PR Newswire. https://www.prnewswire.com/news-releases/quantum-computing-market-worth-20-20-billion-by-2030---exclusive-report-by-marketsandmarkets-302553625.html ↩

  7. Gidney, C., & Ekerå, M. (2021). How to factor 2048 bit RSA integers in 8 hours using 20 million noisy qubits. Quantum, 5, 433. https://doi.org/10.22331/q-2021-04-15-433 ↩

  8. Webster, P., Berent, L., Chandra, O., Hockings, E. T., Baspin, N., Thomsen, F., Smith, S. C., & Cohen, L. Z. (2026, February 12). The Pinnacle Architecture: Reducing the cost of breaking RSA-2048 to 100,000 physical qubits using quantum LDPC codes. arXiv. https://arxiv.org/abs/2602.11457 ↩

  9. Cain, M., Xu, S., King, A. D., Picard, B., Levine, H., Endres, M., Preskill, J., Huang, H.-Y., & Bluvstein, D. (2026, March 31). Shor’s algorithm is possible with as few as 10,000 reconfigurable atomic qubits. arXiv. https://arxiv.org/abs/2603.28627 ↩

  10. National Institute of Standards and Technology. (2022). Status report on the third round of the NIST post-quantum cryptography standardization process. https://doi.org/10.6028/NIST.IR.8413 ↩

  11. Castryck, W., & Decru, T. (2022). An efficient key recovery attack on SIDH. In Advances in Cryptology – CRYPTO 2022 (Lecture Notes in Computer Science, Vol. 13508). Springer. https://doi.org/10.1007/978-3-031-15982-4_6 ↩

  12. Cybersecurity Ventures. (2024). Cybercrime to cost the world $9.5 trillion USD annually in 2024. https://cybersecurityventures.com/cybercrime-to-cost-the-world-9-trillion-annually-in-2024/ ↩

  13. Anthropic. (2026, April 7). Project Glasswing: Securing critical software for the AI era. https://www.anthropic.com/glasswing ↩

  14. McKinsey & Company. (2024). Global banking annual review 2024. https://www.mckinsey.com/industries/financial-services/our-insights/global-banking-annual-review-2024 ↩

  15. Yin, J., Cao, Y., Li, Y.-H., Liao, S.-K., Zhang, L., Ren, J.-G., Cai, W.-Q., Liu, W.-Y., Li, B., Dai, H., Li, G.-B., Lu, Q.-M., Gong, Y.-H., Xu, Y., Li, S.-L., Li, F.-Z., Yin, Y.-Y., Jiang, Z.-Q., Li, M., … Pan, J.-W. (2017). Satellite-based entanglement distribution over 1200 kilometers. Science, 356(6343), 1140–1144. https://doi.org/10.1126/science.aan3211 ↩

  16. Jones, H. W. (2020). The recent large reduction in space launch cost (NASA Technical Report No. 20200001093). NASA. https://ntrs.nasa.gov/citations/20200001093 ↩

  17. Davis, M. (2024, October 15). The Starship revolution in space. The Strategist, Australian Strategic Policy Institute. https://www.aspistrategist.org.au/the-starship-revolution-in-space/ ↩