This is insanely secure... Unless you are an important government leader, a spy or very, very wealthy, it is also totally unnecessary, and will be for decades. Every experimental quantum computer known to exist uses liquid helium cooling, which is inherently expensive (and won't get cheaper). There is NO research in the open press suggesting anyone is within many decades of a room temperature quantum computer, and quite a bit suggesting that such a thing simply cannot exist.
If we are still looking at liquid helium cooling (which we will be for the forseeable future) , a quantum computer poses a legitimate security threat - to VERY interesting people. If your email address is something like
joeb@whitehouse.gov or
bezos@amazon.com, you certainly have to worry about someone coming at you with a quantum.computer. If it's
anybody@cia.gov, you MIGHT. If it's
jenniferlawrence@gmail.com, the porn industry is simply going to deepfake you - far cheaper than quantum-hacking your iMessages in hopes you sent out a nude selfie. If it's pretty much anything else, you aren't going to be attacked by anyone with THAT kind of resources.
This is similar to all the threats that require extended, in-person access to your laptop or phone and expensive tools. If your last name is Biden, you might not want to leave your computer lying around. If you are the CEO of Goldman Sachs, you might want to be careful not to leave the company passwords in a text file (and it's amazing how many CEOs do things like that!). If you're an ordinary person, you should be far more concerned about things that aren't encrypted AT ALL and can be collected by random idiots, and about phishing e-mails, malware, etc.
Most data security, for most people, isn't about being smarter than the intelligence agencies of a well-resourced nation state (if you are the late Alexei Navalny, it certainly was). It's about being a step ahead of teenage script kiddies, indiscriminate data vacuums and advertisers who want your data.
Using WhatsApp (Meta's data habits are well known) is just dumb, but either existing iMessage or Signal security is perfectly good unless you have the FSB (better known by their old name - KGB) after you.
It's FAR more important to secure the BIG data leaks like advertising and phishing than to worry about the tiny probability of a professional spy with a supercomputer. The Meta Pixel and friends are HUGE threats, fake credit card readers are significant threats, and the NSA hacking most people with a quantum computer is a nonexistent threat.
Many people think I'm a security freak - I won't use any Meta product under any circumstances, I religiously use a password manager, and I am EXTREMELY careful about logging into Google from any browser (I do all my searches without login, check my gmail only over imap, and any time I HAVE to login, I immediately log out, close the window and let Cookie do its thing to clean up). I have Cookie set to delete nearly everything every time I close Safari, and I'd never touch Chrome.
With all of these precautions, this is the first time in years I've spared a thought for spies with quantum computers - and I've dismissed them entirely unless you are intersting to a professional spy and worth millions of dollars or rubles to hack.
