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I recently started studying about cryptography and I tried to search the internet but I can't find much about these subjects. I want to see the proof of Shamir's Secret Sharing being Proactive and dealer-free .
Later Edit: I found the proof of it being proactive, however I still struggle with the 2nd thing. Basically, if the users know (k,n,p) , how can they compute a secret with none of them knowing it ?