The Fingerprint property returns a string that consists of
a series of hexadecimal values separated by colons. The value is
unique to the server, and is an MD5 hash of the RSA host key. An
application can use this value to determine if a connection has been
established with the server previously by storing the server's host
name, IP address and fingerprint in a file, registry key or a
database.
Note that this property only returns a meaningful value after a
secure connection has been established using the SSH protocol. For
all other connections, it will return an empty string.