I guess if youre really paranoid, 2048 bits might be taking a risk at some point. But I'm truly skeptical. 10^12 is a big factor. I suspect that most of our computational performance is now going to come from massive parallelism, and not processor frequency. We still have a little room in processor frequency, but not a whole lot, certainly not 1000x, much less 10^6. If you made 2048 bit (or more) processors, that would certainly help alot, and if you could build lots of them in 3D instead of close to 2D like we currently do, then that would buy you some more power. But getting a million million times more I just dont see it in 25 to 30 years. More like 200 to 300 years. But technology is always finding new ways to keep up with Moore's law isn't it?
Or alternatively wait for quantum computers to be realised, which will allow public-key ciphers to be broken instantaneously.
S
