Quantum computers are mainly a threat to naive investors.
Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
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Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#72Quantum computers are mainly a threat to naive investors.
Yeah, but… what if?
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#73Earlier quoted context omitted.
The power and heat are the issues for that, though. Think about how much energy and heat are used/generated in the chips we have now. If we tiled out those chips to be 20 orders of magnitude larger… where is the heat going to go, and where is the energy coming from?
In my example I had imagined that your nanobots would also create solar panels and radiators for the chips you were tiling the surface of mars with. This is why it needs to be done on the surface instead of underground somewhere.
By the time you built this machine, someone could just bump to 256 bit AES and you suddenly need a billion Marses covered in chips.
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#74Earlier quoted context omitted.
> You already have to assume the most likely adversary is the entity running the free wifi why do you have to assume that? you're at Acme Coffeeshop. their wifi password is "greatcoffee" and it's printed next to the cash register where all customers can see it. with WPA2 you have to consider N possible adversaries - Acme Coffee themselves, as well as every single other person at the coffeeshop. ...and also anyone els…
Because it's a near certainty (at least in the US) that businesses will spy on you to the extent that they can, but it's actually incredibly rare to be around a nerd with Wireshark? Things like facebook used to not use https long after public wifi was ubiquitous and you could easily sniff people, and it basically didn't matter. Now nearly everything uses TLS so it really doesn't matter. Actually most public wifi I en…
> Actually most public wifi I encounter has no security.
that was also one of the things fixed [0] in WPA3.
it sounds like you don't consider it relevant to your personal threat model. but the experts in charge of the standard apparently thought it was important to have in general.
0: https://en.wikipedia.org/wiki/Opportunistic_Wireless_Encrypt...
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#75I think quantum may be practically mitigated with aggressive key rotation in some cases. I've been prototyping an oauth machine-to-machine integration with a banking vendor that has our ecdsa keys rotate every 5 minutes. The keys are scheduled for deletion after 10 minutes. I see no reason I couldn't reduce this to something like 30s/60s. Our counterparty frequently scans our JWKS endpoint for revocation, so in pract…
Wouldn’t using opaque tokens have avoided the problem altogether?
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#76[flagged]
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#77Earlier quoted context omitted.
You don't need to keep shrinking features. Brute forcing is highly parallel; to break a key within a certain time frame all you need is a large enough quantity of chips. While it's in the realm of science fiction today, in a few centuries we might have nanorobots that can tile the entire surface of mars with processors. That would get you enough orders of magnitude of additional compute to break a 128 bit key. 256 bi…
Classical brute force is embarrassingly parallel, but Grover's algorithm (the quantum version) isn't. To the extent you parallelize it, you lose the quantum advantage, which means that to speed it up by a factor of N, you need N^2 processors. The article discusses this in detail, and calculates that "This means we’ll need 140 trillion quantum circuits of 724 logical qubits each operating in parallel for 10 years to b…
So then why is quantum always touted as being able to possibly beat AES ?
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#78Earlier quoted context omitted.
Classical brute force is embarrassingly parallel, but Grover's algorithm (the quantum version) isn't. To the extent you parallelize it, you lose the quantum advantage, which means that to speed it up by a factor of N, you need N^2 processors. The article discusses this in detail, and calculates that "This means we’ll need 140 trillion quantum circuits of 724 logical qubits each operating in parallel for 10 years to b…
So then why is quantum always touted as being able to possibly beat AES ?
Because some people make their living from the vague possibly it might work one day. It's the cold fusion of computing.
Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#79Re: Quantum Computers Are Not a Threat to 128-Bit Symmetric Keys
#80Interesting approach — curious how this scales under real load.