While executing the security server program, the server: verifies client access rights via a first encryption means, generates, encrypts and transmits to the client a random port number and a session key, and detects establishment of {HEAD ~ a second connection} between the client and {TAIL ~ a random port} of the server 
between
While executing the security server program , the server : verifies client access rights via a first encryption means , generates , encrypts and transmits to the client a random port number and a session key , and detects establishment of { HEAD ~ a second connection } between the client and { TAIL ~ a random port } of the server
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH