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