Encryption is enabled by the exchange of at least one key and the generation of additional keys by the access point and {HEAD ~ the mobile computing unit} to make {TAIL ~ the communications} secure 
to make
Encryption is enabled by the exchange of at least one key and the generation of additional keys by the access point and { HEAD ~ the mobile computing unit } to make { TAIL ~ the communications } secure
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH