A biometric and cryptographic processing unit includes {HEAD ~ a biometric receiver} receiving biometric information of {TAIL ~ a BCU user} 
A biometric and cryptographic processing unit includes { HEAD ~ a biometric receiver } receiving biometric information of { TAIL ~ a BCU user }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL