When submitting the info for a CSR in our Control Panel (for an SSL certificate), there are two choices for the bit rate; 1024 and 2048.

When you go to the certificate provider they will typically offer bit rates of 128 or 256 bit.

Don't let the differences in bit rates confuse you! The important thing to note here is that our stated bit rate of 1024 and 2048 is the provider (server) bit rate. The certificate authority bit rates of 128 or 256 are the encryption rates for the actual communication channel (the browser communication). The two values will not match.

In the vast majority of cases you should select the 1024 bit rate in Control Panel. 2048 is reserved for special high-end certificates that are rarely purchased by the general public.