This is really simple. You'll notice that each replaced phase was a 0 or 1 -- a bit. So to scale to 256 you only need 8 (2^8)of those option phrases, or to 65536 16 (2^16) phrases. Such would be easy in an email the length that was posted.
"You can't get very far in this world without your dossier being there first." -- Arthur Miller