If one cell contain certain word, then total row will be hide and protect

Is it what you want
Overall see file attached

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
Const WkPW As String = "MyPassWord"
Const WkKW As String = "HIDDEN"
   If (Target.Column <> 3) Then Exit Sub
   If (Target.Value = WkKW) Then
      Rows(Target.Row & ":" & Target.Row).EntireRow.Hidden = True
      Rows(Target.Row & ":" & Target.Row).EntireRow.Locked = True
      With Sheets("Data")
          .Protect Password:=WkPW, UserInterfaceOnly:=True
      End With
   End If
End Sub