Most quantum computer scientists are complicit hackers
Quantum computers can be more efficient than classical computers on some tasks. Quantum computers cannot simply take any classical computational task and reduce its time to completion. A computational task can be solved more efficiently by a quantum computer only in some special circumstances, such as when the task can be translated to a quantum mechanics problem which is what quantum computers were designed to solve. The precise details, of which tasks see their time to completion reduced by quantum computers, come down to a serendipity between the mathematics of the computational task and of quantum computing. In fact the quantum computing community hasn't even fully understood which problems can and cannot be sped up by quantum computers. The key point to note is that quantum computers speed up the completion of some computational tasks far more than others. For example, quantum computers provide only a small speedup over search, but they make prime factorisation of large numbers practicable, which is otherwise astronomically difficult on classical computers. Prime factorisation is the task of splitting up a number into prime factors. For example the prime factorisation of is , and the prime factorisation of is . Finding the prime factorisation of very large numbers is something quantum computers can do very fast but classical computers cannot.
Just like classical computing is built on a "stack" of technologies, quantum computing is also being built in a "stack". A stack allows separation of concerns. The hardware engineers and the software engineers can work independently from one another, as long as they agree to how their interface will behave.
I have friends and colleagues who work on all kinds of important aspects of the quantum computing stack - things like quantum programming languages, compilation of quantum programs, quantum circuit simplification, distributing tasks across networked quantum computers, fault tolerance of quantum computers, designing better qubits, qubit control software, qubit control hardware, and so on. All of these enabling technologies will come together to enable quantum computing.
The hope is that all this effort will enable us to use quantum computers to do many things. So far however, not that many applications of quantum computing are known. I also believe that there is quite a shortage of people working on creating new quantum algorithms, or identifying applications of quantum computers. But work in all aspects of the quantum computing stack continues with the hope that it will be an omni-purpose computing technology that will bring many benefits to society.
Here lies a moral conundrum for the quantum computing scientist. There is one sure potential application of quantum computers - a quantum computer can be deployed to break the encryption that keeps our internet activity and messaging confidential. Thus, if you just work on the enabling technologies that go into quantum computing, you are steering us into a world where quantum computers will be used to break codes. This will probably lead to at least some harms such as an arms race between powerful governments, espionage, exposing private information that wasn't meant to be public, government surveillance and loss of trust in digital infrastructure. Instead, you can divert at least some small portion of your research activity to working directly in identifying and mitigating the quantum computing threat to information security. This will ensure that quantum computing capability develops together with preparations to mitigate the harms that we know it is likely to bring.
Even if each member of the quantum computing technology community is not obliged to work on these other directions, I think at least some greater percentage of the community who work on enabling technologies should be more mindful of this likely direct consequence of their work, and take at least some steps to mitigate these harms. In my experience in the field, this is just viewed as a different topic that other people will work on, and at the same time I don’t see enough work being done on it.
What are some efforts needed in this direction?
- Understanding the threat (from these perspectives: technical details, societal implications, attacker motivations, attack types)
- Developing post-quantum cryptography and quantum key distribution (these are alternatives to the codes that will be broken by quantum computers)
- Safeguards that ensure that even when quantum computers are built, they will be preventions in place against breaking codes on quantum computers
- Standards of transparency in quantum computing development
- Education about the threat, training workforce to know how to respond, training individuals to discern what kinds of technologies are quantum-safe
- Ethics education for quantum computing researchers
- Diplomacy and international coordination in the face of this challenge. For example, sharing best practices and helping countries with less quantum computing capability understand and respond to these threats as well.