We investigate bidder collusion in one-sided ascending price auctions without communication. If bidding rules in an English-type auction allow bidders to match each others' bids, collusion can be sustained as a Nash equilibrium of a one-shot auction game. Our earlier experiments show that in common value auctions with complete information, collusion does occur and is sustainable even when bidde...

Collusion is covert co-operation between participants of a game. It poses serious technical, game design, and communal problems to multiplayer games that do not allow the players to share knowledge or resources with other players. In this paper, we review different types of collusion and introduce two measures for collusion detection. We also propose a model and a simple game, implemented in a ...

Collusion is covert co-operation between participants of a game. It poses a serious problem to multiplayer games that do not allow the players to share knowledge or resources with other players. Fair play requires that players act independently to gain best possible individual result and are also able to analyse the action-reaction loop of the other players. In this paper, we discern two basic ...

A contract with multiple agents may be susceptible to collusion. We show that agents’ collusion can be prevented at no cost in a large class of circumstances with risk neutral agents — virtually all circumstances with uncorrelated types and a broad set of circumstances with correlated types. In those circumstances, an optimal outcome in the absence of collusion can be made collusion proof, in a...

The theoretical literature on collusion in auctions suggests that the first-price mechanism can deter the formation of bidding rings. In equilibrium, collusive negotiations are either successful or are avoided altogether, hence such analysis neglects the effects of failed collusion attempts. In such contingencies, information revealed in the negotiation process is likely to affect the bidding b...

Though there is a body of theoretical literature on research joint venture (RJV) participation facilitating collusion, empirical tests are rare. Even more so, there are few empirical tests on the general theme of collusion. This note tries to fill this gap by assuming a correspondence between the stability of research joint ventures and collusion. By using data from the US National Cooperation ...

Digital fingerprinting is a technology for tracing the distribution of multimedia content and protecting them from unauthorized redistribution. Collusion attack is a cost effective attack against digital fingerprinting where several copies with the same content but different fingerprints are combined to remove the original fingerprints. In this paper, we consider average attack and several nonl...

We study tacit collusion in repeated auctions in which bidders can only observe past winners and not their bids. We adopt a stringent interpretation of tacit collusion as collusion without communication about strategies that we model as a symmetry restriction on repeated game strategies: Strategies cannot discriminate among initially nameless bidders until they have become named through winning...

Inner product encryption (IPE) is a new cryptographic primitive initially proposed by Abdalla et al. in 2015. IPE can be classified into public-key IPE and secret-key IPE. The currently proposed PK-IPE schemes can-not resist the following collusion attack: an invalid user that holds no private key can ”buy” a combined key generated from multiple collusion adversaries, and the user can use this ...

Dynamic spectrum auction is an effective solution to manage spectrum across many small networks. As the number of participants grows, collusion poses a serious threat to auction performance. Small groups of colluding bidders can make use of the interference constraints to manipulate auction outcomes, leading to unfair spectrum distribution and significant loss in auction revenue. Prior designs,...