Select the key pair type(s) and associated key pair size(s) from the pulldown menus. [Details]
Each key pair is comprised of a key type and a key size. Based upon the key type selected from the first pulldown menu, associated key sizes (in bits) will be selectable from the second pulldown menu.
Within each key pair type (but not comparable between two different key pair types), the size of the key is a measure of how secure a given system is (i.e. - the longer the key pair size, the more secure the system). Unfortunately, longer key pair sizes increase the time required to perform operations such as signing certificates.