In response, the first computer system generates {HEAD ~ a message}, encrypts the generated message, and transmits {TAIL ~ the encrypted message} to the second computer system 
In response , the first computer system generates { HEAD ~ a message } , encrypts the generated message , and transmits { TAIL ~ the encrypted message } to the second computer system
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH