the engine used in the antique fedora5 is vastly different than the one used in fedora 17
and a few known holes have been fixed and a new algorithm is used ( i think)
BUT unless you ARE a EXPERT in "cracking" encrypted files there is no easy way to unencrypt the files WITHOUT the original fedora key FROM the old fedora 5 install
even then was it gnomes key ring ? or KDE3's key ring ?
a public / private pair with the public half posted to a public server
and the private on the fedora key-ring ( or 3.5 floppy)
Does the data exprire after time?
no, unless YOU set it to
but after time the old keys get lost
And on fedora with a NEW install EVERY 6 months
not only is it likely but almost a 100% certain fact that they WILL get lost