Comment by withinboredom

> Does this address your comment better?

Much! I'd say that there is always a counter-example. However, even RSA was generally recommended as "insecure" because people can't bother to do any research into the correct values of the parameters. The algorithm itself is secure, but most libraries didn't have sane/secure defaults until like 10ish years ago.

That was the point I was trying to make, you're making a bet that what we know today will still be true 20 years from now. The algorithms you mentioned are symmetric, IIRC, and basically any symmetric algorithm is secure as long as you have a one-time-pad or don't know any of the cleartext. That is, until someone finds a flaw with it.

I remember working on my first 'ciphersaber[1]' when it was discovered it was insecure.

> Most operating systems can run software from 20 years ago.

I was mostly referring to main-stream OS's. Linux and OSX, for example, cannot run software compiled 20 years ago (I'd love to be proven wrong, but my experience hasn't been so great!). On my modern Windows 11 PC, I can still run my first game engine demo, written and compiled in 1998 (I've since lost the source code). Or via WINE on my Linux PC, probably.

I'm sure there are niche cases out there, but the vast majority of people don't have access to those systems and OS's, while anyone can (currently) run a basic version of Windows for free.

[1]: http://ciphersaber.gurus.org/