I'm assuming you're asking because you can see your eBay ID in a list of bids while everyone else's appears as something like "t***s".
Don't worry. Your identity IS protected. Only you and the seller can see your ID in the list of bids. Everyone else will see it as something like "r***7".
Likewise, only the other bidders (and the seller) can see their own ID. You have no way of finding out who the other bidders are.