I have read that GnuPG limits the size of RSA keys to 4096-bits because this could lead
to problems with running out of secure memory. But in which operation is this the case?
Generating the keys? Encryption? Decryption? Signing? Verifying? All of them?
I have now modified the source code of GnuPG to allow me to generate 8192-bits keys just to test, and am generating such a key as I write this post. I have also increased the size of secure memory to 65K.
Can I expect problems with other PGP implementations with 8192-bit RSA keys?