We the Quantum Punks are building a future improved by quantum technologies and secured by physics. We work to accelerate the research, development, and adoption of quantum cryptography.

Our thesis:

- New Applications: quantum physics uniquely enables a set of novel, superior applications of cryptography to secure the internet and protect digital rights.
- Quantum Accelerationism: the near-term potential of these applications will accelerate progress in quantum cryptography, in turn accelerating quantum technologies and their impact on humanity.

__We believe in quantum optimism. __While many focus on defending classical cryptography against quantum technologies, we think it’s time for more people to explore what quantum technologies can do *for* cryptography¹.

__We believe in using quantum physics to build more secure systems.__ Classical cryptography relies on computational hardness assumptions for its security.² In contrast, quantum cryptography relies on the laws of quantum physics. In many cases, breaking systems secured with this cryptography would entail breaking the laws of physics themselves. This is a fundamentally safer approach to securing digital systems [1].

__We believe in using quantum physics to build uniquely new cryptography.__ In the quantum realm, cryptographers have new theoretical tools such as entanglement [2][3] and the no-cloning theorem [4]. With these, we get new cryptography that is classically impossible to construct such as one-time programs, digital copy-protection, uncloneable encryption, device-independent protocols [5, 6], one-shot signatures [7], and more. This leads to the creation of new applications like Wiesner’s Quantum Money [8] — digital currency with true physical cash-like properties. Classical digital currency requires some form of a trusted third party, whether a bank or a blockchain, to order transactions to prevent double spending. Instead, when money is encoded in quantum states, it cannot be spent more than once since quantum state cannot be cloned. The double-spending problem is inherently solved by physics, creating a digital currency that’s ledgerless, yet still peer-to-peer and privacy-preserving.

__We believe in the near-term potential of quantum cryptography.__ Quantum technology is often dismissed because it hinges on the existence of large scale quantum computers, a technology that is not yet practical³. Fortunately, some applications of quantum cryptography do not require quantum computers, and instead require more accessible hardware for sampling and communicating quantum states. As quantum crypto applications are not bottlenecked on the existence of quantum computers, we believe their growth will be unhindered, leading to faster applicability.

__We believe cryptography applications will catalyze progress in quantum technologies.__ While applications like quantum key distribution [9] and quantum random number generation are already deployed today [10][11], we believe there are more low hanging fruits in cypherpunk applications of quantum technology. In many ways, quantum cryptography is the cypherpunk endgame: cryptographic systems so fundamentally secure that they enshrine digital freedom and self-sovereignty as inalienable rights [12]. As demand for new applications motivate breakthroughs in quantum cryptography, we expect there will be many positive externalities on the broader quantum space: better quantum memories, better communication technology to link quantum computers together, networks based on quantum-teleportation, and many more that we cannot fathom today⁴.

In summary, we believe that quantum physics uniquely enables a set of novel, superior applications of cryptography to secure the internet and protect digital rights. And that, as demand for these accelerate the practicality of quantum cryptography, quantum cryptography will accelerate the quantum industry, propelling us to new frontiers in science, technology and society⁵.

A future improved by quantum technologies and secured by physics isn't so distant — it's ours to seize. This is an invitation. To the researchers exploring the boundaries of what's possible. To the engineers turning theory into reality. To the cypherpunks carrying the torch of digital liberty. To the solarpunks building a brighter world powered by nature, we say: the quantum future beckons.

*2024-09-04*

*Written by **Nicola Greco** and **Alex Obadia**, with help from **Marc Kaplan**, **Andrew Miller**, **Fabrizio Romano Genovese**, **Stefano Gogioso**, **Will Zeng**, **Sylvain Bellemare**, **Yannick Roux**, **Jonatan L-B**, **Max Mersch**, **Alex North**, **Kailin Rutherford**, Cesare de Michelis, Giorgia Conta and **Lakshman Sankar**.*

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**Notes**

¹ Powerful enough quantum computers can break parts of classical cryptography. For example, one can in theory use Shor’s factoring algorithm to break cryptographic schemes relying on prime number factorisation such as RSA. There exist an industry and academic movement dedicated to defending against this looming risk, primarily by working on upgrading today’s systems to 'post-quantum secure cryptography'/'quantum-safe cryptography'.

² Classical cryptography relies on computational assumptions for its security —the belief that specific mathematical problems are ‘hard’ to solve by an adversary’s computer, even with very large amount of resources. This “hardness” is used to secure the protocol using it. Two notable assumptions are the discrete log assumption, used in Diffie-Hellman key exchange, and the prime number factorization assumption, used in RSA.

³ While many milestones have been reached on the road to large-scale quantum computers, experts are still divided on the timeline under which quantum computers will reach their full potential. Companies like PsiQuantum and Google estimate they will achieve this under 10 years, while others expect it to take more than 20 years.

⁴ Quantum cryptography requires precise control and measurement of quantum states over long distances. This, in turn, necessitates the advancement of quantum communication technologies such as better quantum memories (to store and manipulate entangled states), quantum repeaters (to extend the range of quantum communication), new communication mediums (via specialized optical fibers, satellites), and new communication techniques (like teleportation). Their development also positively impacts the broader quantum space as they are essential for other applications. For instance, improved quantum memories and communication networks help enable distributed quantum computing.

⁵ Quantum computers can be used to simulate complex molecular structures for more accurate climate forecasting, materials discovery for next-generation batteries and chemistry research. Quantum sensors could detect minute changes in electromagnetic fields, for applications such as enhancing the resolution of brain-computer interfaces and improving the precision of medical imaging. Perhaps most profoundly, by manipulating increasingly complex quantum systems, we could gain a new understanding of the nature of the quantum world itself [13].

**References**

[1] Bennett, C. (1992). *Quantum Cryptography: Uncertainty in the Service of Privacy*.

[2] Schrödinger, E. (1935). *Discussion of Probability Relations Between Separated Systems*.

[3] Einstein, A., Podolsky, B., & Rosen, N. (1935). *Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?*.

[4] Wootters, W., & Zurek, W. (1982). *A Single Quantum Cannot be Cloned*.

[5] Sattath, O. (2022). *Uncloneable Cryptography*.

[6] Colbeck, R. (2006). *Quantum And Relativistic Protocols For Secure Multi-Party Computation*. *Chapter 5.*

[7] Amos, R., Georgiou, M., Kiayias, A., & Zhandry, M. (2020). *One-shot Signatures and Applications to Hybrid Quantum/Classical Authentication*.

[8] Wiesner, S. (1983). *Conjugate Coding*.

[9] Brassard, G., & Bennett, C. (1984). *Quantum Cryptography: Public Key Distribution and Coin Tossing*.

[10] IDQuantique. (2023). *Samsung Galaxy Quantum 5 smartphone*.

[11] Chinese Academy of Sciences. (2017). *Beijing-Shanghai Quantum Communication Network Put into Use*.

[12] May, T. (1993). *A Cypherpunk’s Manifesto*.

[13] Brassard, G. (2005). *Is Information the Key?*.