In step 203, the signature key generator 123 uses a hashing function to generate {HEAD ~ a signature key} for {TAIL ~ the fingerprint} 
for
In step 203 , the signature key generator 123 uses a hashing function to generate { HEAD ~ a signature key } for { TAIL ~ the fingerprint }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL