I run a site which is essentially an e-commerce platform where buyers connect with sellers and all transactions happen in Bitcoin. I worry about sellers on the site continuously buying their own items on the site to gain visibility (more sales means higher ranking on the front page).
Is it possible to detect whether an incoming transaction originated from the same bitcoin wallet?
I am thinking that I could run a tree/graph traversal of transactions starting at a given payment address and see if I end up at that same address again. But I'm not sure how this would work with wallets where each payment generates a new address from a master public/private key pair. As far as I know, it's not possible to tell whether two addresses originated from the same MPK.
PS: Maybe wash sale is not the correct term here.