These days I keep coming back to the “security patching and updates” issue. So I am going to add another couple of comments.
The first is about Ripple 20 (here the official link but the news is already wide spread) which carries an impressive number of “CVSS v3 base score 10.0” vulnerabilities. The question is again:
how can we secure all of these Million/Billion vulnerable devices since it seems very likely that security patching is not an option for most of them?
The second one is very hypothetical, that is in the “food for thought” class.
Assume, as some says, that in 2030 Quantum Computers will be powerful enough to break RSA and other asymmetrical cryptographic algorithms, and that at the same time (or just before) Post Quantum Cryptography will deliver us new secure algorithms to substitute RSA and friends. At first sight all looks ok: we will have just to do a lot of security patching/updating of servers, clients, applications, CA certificates, credit cards (hardware), telephone SIMs (hardware), security keys (hardware), Hardware Security Modules (HSM) and so on and on… But what about all those micro/embedded/IoT devices in which the current cryptographic algorithms are baked into? And all of those large devices (like aircrafts but also cars) which have been designed with cryptographic algorithms baked into them (no change possible)? We will probably have to choose between living dangerously or buy a new one. Or we could be forced to buy a new one, if the device will not be able to work anymore since its old algorithm will not be accepted by the rest of the world.
PS. Concerning Quantum Computers, as far as I know nobody claims that a full Quantum Computer will be functioning by 2030, this is only the earliest possible estimate of arrival, but it could take much much longer, or even never!
PS. I deliberately do not want to consider the scenario in which full Quantum Computers are available and Post Quantum Cryptography is not.