纯引用
https://www.gnupg.org/faq/gnupg-faq.html#no_default_of_rsa4096> A keysize of 2048 is sufficient. Using 4096 "gives us almost nothing, while costing us quite a lot."
> If you need more security than RSA-2048 offers, the way to go would be to switch to elliptical curve cryptography — not to continue using RSA.
> 11.6 Why does GnuPG support RSA-4096 if it ’ s such a bad idea?
> RSA-4096 is not a bad idea: it ’ s just, generally speaking, unnecessary. You gain very little in the way of additional resistance to brute-forcing and cryptanalysis.