I'm going to present a paper, in which we propose several algorithms to solve a problem. One of the algorithms is actually developed by co-authors at a different university, who will not attend the conference.
I only understand this algorithm at a very high level, and I have no idea how it is implemented, which parameters was chosen etc. It uses some techniques that I have very little background. It would take me months to understand all the techniques and the implementation. And to be honest, I'm not really interested in this algorithm since we have other alternatives that perform equally well if not much better.
However, if I am asked about this algorithm at the conference, how I should reply. I couldn't say somebody else did it, and I don't know.