At operation 2006 the reader verifies {HEAD ~ the TPK} using the SAPK and {TAIL ~ ES} 
using
At operation 2006 the reader verifies { HEAD ~ the TPK } using the SAPK and { TAIL ~ ES }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL