The secondary table index used to select
one of the client authentication public
keys for a particular remote access Id.
The index is an integer value from 1 to N
where N is the number of keys associated
with a particular remote access Id.
An addition always causes the value of N to increase
by one, effectively adding an entry after the
existing keys for that remote access Id.
The underlying SSH server implementation searches
the keys in order from 1 to N when attempting public
NOTE:A maximum of 4 public keys can be installed
for one remote access Id.