title: What data type is suitable to handle binary data in ActiveX method?
body: <p>I'm writing an ActiveX control for my friend, that should encapsulate encryption routines. It will be used from VB6 primarily. What data type should I choose for binary data like encryption key, initialization vector, input and output data so that it would be convenient for my friend to use it from VB6?</p>
  
  <p>I'm using Delphi 7 to write this ActiveX, if that matters. One choice is to use hexadecimal strings. What can be the other?</p>