[Cryptography] Why full-fledged quantum computers might always be five years away

[Jon Callas]

> On Aug 4, 2026, at 01:26, Peter Gutmann <pgut001 at cs.auckland.ac.nz> wrote:
> 
> Jon Callas <jon at callas.org> writes:
> 
>> And analog computers were a thing ages ago, there's no reason they can't be
>> again.
> 
> They're still a thing today, everyone here has several of them in places like
> their living room: In their TV, in their stereo/sound system/whatever, in
> their phone, in all sorts of other places, anything that has an amplifier in
> it.  For non-electronics people, the devices that perform this function are
> called op amps.  They're called op amps because it's short for operational
> amplifier, a high-gain differential-voltage controlled amplifier originally
> created to perform arithmetic operations, addition, subtraction, integration,
> differentiation, summation, logarithms, etc, for use in analog computers.

Okay, so analog computers are computers. Glad we agree on that.

> 
> Arguably the op amp(s) in your TV are even more of a computer than a "quantum
> computer" because they can perform operations over arbitrary input values
> (within electrical limits) without having to be rewired every time an input
> value changes.
> 
> In terms of actual analog computers that don't rely on QC-style sleight-of-
> word trickery to get their name, there are a number of companies working on
> them, principally chasing the AI gravy train, because you can calculate to
> more or less arbitrary precision for free.  It's all experimental or chasing
> VC funding though AFAIK.

One of the things I like about the New Scientist reporting is the snark in their headlines. Over the last few months, they've been explicitly saying "useful" quantum computers, or some other oblique slur.

There are two things going on, one being that the QIS people seem to be about to make some progress on an actual experiment that once replicated would be useful. I read one where they're using quantum to verify that aluminum is shiny. Yay.

The other is, as we all know here that QC is smoke and mirrors, though that's euphemistic for smoke. The aluminum thing might get a mirror for them.

This is why it's so exasperating. Some of the other results really are for the first time interesting, and yet we don't have anything useful yet. Meanwhile OMG, we're going to go from cheating to doom of the internet really soon now.

	Jon