Read the original article: PuTTY And FileZilla Use The Same Fingerprint Registry Keys, (Sun, May 2nd)
Many SSH clients can remember SSH servers' fingerprints. This can serve as a safety mechanism: you get a warning when the server you want to connect to, has no longer the same fingerprint. And then you can decide what to do: continue with the connection, or stop and try to figure out what is going on.
Read the original article: PuTTY And FileZilla Use The Same Fingerprint Registry Keys, (Sun, May 2nd)