How much would a quantum computing network rely on power?

[Christopheles]

Let's say an entire city runs on a network run by quantum computing. Fail safe locks are run by this network.

Would triggering a massive unlocking of the city be a simple matter of killing the main power to shut down the quantum network (by shutting down the cooling systems)? It seems logical but I'm not sure if the answer is as simple as that. Any thoughts on this? Thank you in advance.

 

[jambaugh]

Firstly I personally doubt you're going to see quantum computing implemented in the same way, i.e. network infrastructure, as classical computing. The principle power consumption of quantum computing will likely be refrigeration of one form or the other since maintaining coherence in a large ensemble is crucial for scaling quantum computing. I think a more realistic scenario is with quantum computing units as peripheral devices (like GPU's utilized for parallel processing).

But I will wager that no "quantum computer" will be built in our lifetime that can demonstrate, for a practical problem, the implied speed improvement. Rather quantum information theory will be implemented in specialized, empirically secure encryption key sharing.

 

[Christopheles]

You might be right about no quantum computing in our lifetime that will improve speed. But I'm writing science fiction set 200 years from now, so this is all theoretical anyway. I'm sure if my story got pulled out of a dustbin in 200 years, my idea would be laughed at anyway.

In the story, I am using it for key encryption (applied to physical locks, in this case). I am looking for ways that a person would try to make the system fail (hence the power question) so that the fail safe locks would ensure that the physical lock system would go to a default unlock and free the good people of my futuristic city.

I guess then, in relation to your answer, it is feasible that attacking the power source could effectively create a failure in the refrigeration system, thus "messing everything up" (my simplistic way of understanding it) and activating the fail safe unlock...?

 

[Christopheles]

And also, what do you speculate such a system would look like? Would it be physically connected in an enclosed system for the key encryption to work (kind of like the closed loop at CERN where particles can travel at speed)?

 

[jambaugh]

For the key distribution? I don't know. I always envisioned specialized fiber-optics and using photons for the information carrying qubits but I don't know how that can be implemented over distances. You can't amplify the qubit because that is equivalent to measuring it.

On this topic I wouldn't worry about being realistic since anything one come's up with will likely end up being totally wrong. Look at Heinlein's vision of space exploration and automation. But never let facts get in the way of good story telling. (If you're asking w.r.t. SF writing ). The key element of tech in a story is not to let it become "magic" in the form of being unlimited and inscrutable.

 

[jambaugh]

I did not see your second post in my reply (only the 3rd) so let me address your goal more specifically. I would use the analogy of a conventional key. You don't design a lock so that when tumblers break or jam the door swings open. More likely you'll have a "fail safe" as in "fail locked" design. Especially with an encryption system "melting" the key here will loose the data not open it.

Hmmm... to have it physically fail open, I would suggest your hero needs to cause the system to think a specific type of fault occurs and thence "hack" the system open. Say tricking the system into thinking the qubits are about to decohere and forcing a new key refresh/regeneration. Then, hijacking the half of the key pair being sent "securely" to the intended holder and unlocking the system immediately before the interception is detected and thwarted... or something like that.

 

[stefan r]

Let's say an entire city runs on a network run by quantum computing. Fail safe locks are run by this network.

Would triggering a massive unlocking of the city be a simple matter of killing the main power to shut down the quantum network (by shutting down the cooling systems)? It seems logical but I'm not sure if the answer is as simple as that. Any thoughts on this? Thank you in advance.

What advantage would they gain by using a centralized computer system? A network of computers would still run if one shuts down.

Shutting down a city's the power supply is much easier. An important computer/brain is likely to have a back up power supply. Assuming the power grid is similar to our current power grid then electricity flows through sub-stations. A squirrel, party balloon, or a necklace can short circuit a transformer. The US Air Force has a carbon fiber version that shuts down power grids. That cuts the power to both the locks and the computers.

...You don't design a lock so that when tumblers break or jam the door swings open. More likely you'll have a "fail safe" as in "fail locked" design. Especially with an encryption system "melting" the key here will loose the data not open it.

I have never installed one of these. But "fail safe lock" means it opens and "fail secure lock" means it locks when the power goes out. A "fail secure" lock could be dangerous if it means people are trapped on one side during a power failure.

 

[Christopheles]

You guys have opened a few new doors for me (no pun intended). I know I haven't given you all of the information that I'm working with in my story, but you've certainly got the ball rolling for me with your responses. I might be back with a few questions yet but this has been very helpful. Thanks!