Given this verification model above, a bid submission consists of m messages (one to each auctioneer) from the bidder, each of size points. The auctioneers then verify the submission by an all-to-all communication with messages of size points.
Determining a digit of the selling price causes two occasions for degree reduction: the first when computing the in phase 1, the second when computing the summands of in phase 2. This is a total of multiplications over 4 communication rounds. There is one additional communication round where each auctioneer broadcasts c-1 points to reveal the shares.