anchor.diff:      UsmSecParams =
   	case (catch snmp_pdus:dec_usm_security_parameters(SecParams)) of
   	    {'EXIT', Reason} ->
  +                ?vlog("Failed decode USM security parameters: "
  +                      "~n      ~p", [Reason]),
   		inc(snmpInASNParseErrs),
   		error({parseError, Reason}, []);
   	    Res ->
  
positive.code:     case (catch des_decrypt(PrivKey, MsgPrivParams, EncryptedPDU)) of
  	{ok, DecryptedData} ->
  	    DecryptedData;
  	_ ->
  	    error(usmStatsDecryptionErrors, 
  		  ?usmStatsDecryptionErrors, SecName)
      end;
  
negative.code: 		true -> 
  		    ok;
  		false -> 
                      ?vlog("Not authenticated: "
                            "~n      Sec Name: ~p", [SecName]),
  		    error(usmStatsWrongDigests,
  			  ?usmStatsWrongDigests_instance, SecName)
  	    end;
  