A professor may have stolen an idea I discussed with him: how to proceed? I'm really not sure how to proceed from here.

I'm an undergraduate Computer Science student, planning to earn my MSc in the next couple of years.

A couple of weeks ago, I spoke with a professor (I'll call him A) on an informal setting, and, since he was my teacher on an area relevant to the subject, I discussed with him an idea I had, and about how I was trying to make it my own thesis project.

I have also previously "pitched" this idea to another professor (B). He liked it, and we agreed that once I graduated, he was willing to be my advisor, and I could work on it.

However, I was recently shown the list of thesis proposals for current students, and my idea was among them - being supervised by prof. A, and an unrelated professor, C.

The details are so close to what we have discussed that this is almost surely no coincidence.

Now, I can't say I'm 100% sure he stole my idea, but he didn't mention any of this when we talked, and this thesis list was made after our conversation.

Anything could have happened: either I'm right, or prof. C actually came up with the same idea, or prof. A had a similar idea in the past but didn't tell me about it.

I don't know how to proceed. I am already skeptical of academia - seeing my peers work on projects and write papers that didn't interest them, for the sole purpose of earning an MSc, means I'm not interested on working for it unless it's a subject I really care about. That is - I either find anything I want to work on, or I don't care about earning an MSc at all. This was the case. I found a project I wanted to work on.

My question is on the ethics of what may have happened. I have zero experience on academia or research environments, but I have always considered ideas as important as research. That is, copying an idea is as serious to me as copying research. This would fall into plagiarism. 


Is this perspective shared among actual academics? Am I naive in thinking like this?
Am I right in wanting to "keep" an idea to myself, in order to work on it later?
Should I just stay quiet the next time? Shouldn't I be able to discuss these kind of things with people I consider to be honest or "bona fide", without having to be afraid of being copied?


I see multiple possible courses of action, but in the end, I don't know what I want to achieve. The thesis is already assigned, so I probably won't be able to take it away from the student who got it. I also don't know whether this is an ethics violation from prof. A or not, since this is "just an idea" that I voluntarily shared with him.

I can confront prof. A about this, either sending him an e-mail or speaking with him in person, to get his side of the story.

Or I can go to prof. B and tell him about this situation, to see what are his thoughts on it. He looked interested on working with me on this, so maybe he'll know better how to proceed.

What is the best (or "a good") course of action now? I don't feel I should forget this whole story and move on to a different subject, but I don't see what can be done now.
I think it's very clear that you should talk with (B). You had previously discussed this idea with (B) so s/he knows that it was something that you had been considering. Furthermore, (B) also presumably knows the situation within the department better than you. Maybe (A) is known for doing things like this. Maybe the overlap isn't as serious as you think and (B) can reassure you that you can still do your thesis as you wanted to. No one here can decide whether either one of these is the case.

One word of advice: in talking with (B), present this situation as something that you are concerned about, but stay unemotional and stick to the facts: (B) knows that you were interested in this similar project, you discussed it with (A), and now another student is doing this project with (A). You do not need to connect the dots and accuse (A) directly of plagiarism or dishonest conduct in an initial conversation with (B). If this is a misunderstanding or miscommunication then doing so makes you seem aggressive and prone to jumping to conclusions. If (A) did something that is as blatantly dishonest as you have suggested, then that will be obvious to (B) as well.