Quantum Hacking: China’s Road to Supremacy in National Security
Quantum mechanics, computing and cryptography has gained popularity due to the seemingly odd physics that governs the fundamental particles of the world. This has led to a sustained, incremental increase in popularity of ‘quantum’ based topics worldwide.
However, this increased popularity has led to a dis-proportional increase in click bait or down right factually inaccurate headlines.
These falsified headlines are not usually malevolent, they result from a fundamental illiteracy within science. The United States, which currently ranks 24th and 50th respectively in science and math literacy owns a fair share of the blame (source).
Scientific illiteracy is widespread beyond the general public of the United States. Out of 535 members of the United States Congress (Senate + House of Representatives) only one member holds a PhD in a science related field(source).
Compare this to China where 8 out of the top 9 government officials are scientists and engineers, (source) including their president Xi Jinping who has a degree in chemical engineering and a PhD in law.
This trend is troubling because the United States apathy towards scientific progress is becoming a National security concern. The US won’t be able to draft off of the progress that the Chinese make in certain technological fields; quantum cryptography being one of the most important.
To understand why quantum cryptography is different than previous technologies, it’s useful to classify history’s technologies into two categories:
- Open door technologies. Open door technologies spread opportunity from the creator to the masses. An example of an open door technology was penicillin. Once it was created it was spread, development increased and costs decreased over time until the access to this technology became almost ubiquitous.
- Closed door technologies. Closed door technologies have all of their value extracted by the creator, and the value is concentrated within a single entity. An example of a closed door technology is a fission based nuclear bomb. Once this technology was created it wouldn’t be shared, and it’s creator will extract all of its ‘value’. With certain closed door technologies, no other entity will ever use them, because the initial use will destroy the future prospects i.e. nuclear bomb detonated removes opportunity for others to use it.
China has recognized this difference when it comes to quantum technology, and committed to winning the arms race in quantum cryptography.
To fully appreciate the strategic nature of China’s decision, it’s important to investigate the current state of cryptography, how quantum computing will change that and what the implications are for the future of digital security.
There are a lot of cryptography techniques. For simplicity’s sake the focus here will be on RSA encryption. This type of encryption works primarily based on four items:
- Public Key
- Private Key
- Prime numbers
Let’s take the following example. Say you want to encrypt a message between you and a friend. You could encrypt it by doing the following:
Public key = 25
Private key = the correct prime number factorization of 25 (5, 5).
A prime number is a whole number, that has only two factors — 1 and itself. In this case your receiver would have the private code of the prime numbers (5,5) that matches the public code (25) and the message would unlock. This would be a very bad encryption system because there is only one way to factor 25 with prime numbers (5,5) thus any bad actors could break this encryption quickly.
Now consider that you choose a public key that was 100 digits long and call that number [x]. How would a hacker go about breaking this code?
- They would know that they only need to go up to the square root of the starting public key number [x]. That is because the two prime numbers in the factorization can’t exceed the square root of the public key (source), otherwise when multiplied together they would exceed the size of the public key. This reduces the number of digits comprised in the square root of the public key [x] to ~50 digits. Let’s call this number [y].
- There’s only one way to determine the factors of a non prime number and that is by trying to divide it by all possible prime factors. Now the hackers need to find all of the prime numbers less than [y] and try dividing [x] by each of the prime numbers they’ve discovered. If this calculation results in another prime number then they’ve discovered one potential private key.
- For a 50 digit number, like [y] in our example, there are about ~1110000000000000000000000000000000000000000000000 prime number factor possibilities. That exceeds the number of atoms representing the entirety of earth (source). That means that even if you had a computer trying to divide these prime numbers millions of times a second it would still take you 2111000000000000000000000000000000 years to get the correct factorization to break this encryption (i.e. the sun would have burned out by then). Credit to Scott Welch for the calculations.
It’s important to note that it isn’t hard to do prime number factorization. You were able to factor 25 really quickly. The problem is that you need to use the same process to factor 25 that you’d use to factor a 50 digit number, which is dividing one prime number factorization set at a time.
The problem is that there isn’t a way to efficiently find the prime number factors of a non prime number (known as a composite number). This fact is why encryption has become ubiquitous in communications — and it’s a fact that we’ll return too.
We’ve established that information transfer is secure (i.e. can’t be decrypted) because it takes a prohibitively long time to do prime number factorization. But two important aspects of that problem change with a quantum computer:
- You no longer need to try factors 1 at a time
- You can factor numbers much, much faster
This is possible because quantum computers don’t work like regular computers. A regular computer processes information through binary bits (1,0). A quantum computer is able to process information much faster by using quantum bits (or quibits) that can exist in multiple states at once. Using this technology, scientists have proved that it is theoretically possible to break RSA encryption quite quickly.
Once encryption is broken by a new algorithm run on a quantum computer the natural question will be: how will data transfer be kept secure? Look no further than the Quantum Key Distribution (QKD). This is a way of encoding information into an elementary particle, like a photon. Let’s look at the core components that exist in QKD:
- Entanglement. This is the theory that two particles can be connected across very far distances. The two particles can never share the same state. If one particle is moved to ‘up state’ the second will immediately change to ‘down state’. This fact can be exploited for communication.
- Superposition. This theory says that an elementary particle, like a photon exists in all possible states, but then collapses to one point in space time when it is observed. This can be exploited for security.
In our example let’s suppose you and a friend are looking to securely communicate. You would send information back and forth via you’re entangled photons, in which you’ve encoded information.
But a hacker is interested in what you are saying. So they intercept your message. However the superposition principle tells us that when a photon is observed it changes, and collapses. So when this happens unexpectedly, you would be alerted that someone has attempted to read you message. This type of security system is using the quantum mechanical laws to protect information. The ingenuity of using physics is that you would need to break the laws of physics to break the code of the message. The promise of this level of security is why major nation states are investing resources in creating such a system.
There’s a beauty to China’s approach. They know quantum computing is important and they’re working hard on advancing the technology. But quantum computing is an open door technology. Once research scientists have figured out how to cool particles and keep qubits entangled the technology will spread, and China will take the learning to be #1 or #2 in quantum computing in the world. The technology may even become commercially available.
But once these quantum devices are available, security will become paramount. And that is why China has prioritized winning the battle for quantum cryptography, the closed door technology. The first country to create a prime number factorization algorithm wins. They will decrypt the data of all nation states. Once that happens, it won’t be useful to anybody else. From there, China can employ their Quantum Key Distribution security to make their communications un-hackable.
The future outlook:
One issue with debating policy governing quantum computing, cryptography and algorithmic design is that its an abstract concept that feels like it will only impact future generations. Thus the debate tends to be constrained to the scientifically literate fringe.
However, Amit Katwala of Wired describes the timeline that the tech industry is currently working with:
Quantum computers are beginning to move out of research labs in search of broader investment and applications. In October, Google announced that by the end of this year it expects to achieve quantum supremacy — the point at which a quantum computer can outperform a classical computer.
Because nations around the world, including China, are investing heavily in research and development, the world is likely less than a decade away from the day when a nation-state could use quantum computers to render many of today’s most sophisticated encryption systems useless.
This means that by the end of the year, Google will be able to factor prime numbers more effectively than any computer in the history of the world. Within 10 years we may reach the tipping point where all communications are intercepted and decoded by a government entity.
Intelligence agencies around the world are already preparing for such a day that they can deploy their ‘quantum hacking algorithm’. These intelligence agencies are reportedly intercepting encrypted communications and storing the seemingly useless string of alphanumeric numbers, waiting for a time that they can decrypt them with quantum technology. (source)
This will be a zero sum game. With a closed door technology such as quantum cryptography, only one nation / company can win. The only question is who? If I had to guess I’d bet on the country where the government consists of 90% scientists making funding decisions, not the one with >1%.