If the result of {HEAD ~ the test} in {TAIL ~ step} 401 is NO, then in step 402, the normally unaccessible data is encrypted with the symmetrical encryption Key 
in
If the result of { HEAD ~ the test } in { TAIL ~ step } 401 is NO , then in step 402 , the normally unaccessible data is encrypted with the symmetrical encryption Key
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH