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Auflistung nach Schlagwort "Security Protocols"

1 - 3 von 3
  • Konferenzbeitrag
    Accountable Banking Transactions
    (Open Identity Summit 2024, 2024) Mödersheim, Sebastian; Chen, Siyu
    This paper shows how to apply the idea of Three branches of Accountability by Mödersheim and Cuellar to make banking transactions accountable, i.e., neither can the customer later deny to have placed the order, nor can the bank execute a transaction that the customer did not order. This is done in a general way that deliberately gives freedom to instantiate the system in several different ways, as long as it follows a few basic principles, and we show accountability holds in every instance.
  • Zeitschriftenartikel
    Distributed ascending proxy auction — A cryptographic approach
    (Wirtschaftsinformatik: Vol. 48, No. 1, 2006) Rolli, Daniel; Conrad, Michael; Neumann, Dirk; Sorge, Christoph
    In recent years, auctions have become a very popular price discovery mechanism in the Internet. The common auction formats are typically centralized in nature. The peer-to-peer paradigm demands gearing up auctions for decentralized infrastructures. In this context, this paper proposes a distributed mechanism for ascending second-price auctions that relies on standard cryptographic algorithms. In essence, the auction protocol has the capability of preserving the privacy of the winning bidder’s true valuation.The auction protocol makes use of a high number of auctioneers divided into several groups. A bidder creates an encrypted chain of monotonously increasing bidding steps, where each bidding step can be decrypted by a different auctioneer group. This considerably reduces the attack and manipulation possibilities of malicious auctioneers. In addition, this secure approach does not require bidders to be online unless they are submitting their bid chain to the auctioneers.
  • Konferenzbeitrag
    Private Authentication with Alpha-Beta Privacy
    (Open Identity Summit 2023, 2023) Fernet, Laouen; Mödersheim, Sebastian
    Alpha-beta privacy is a new approach for security protocols that aims to provide a logical and intuitive way of specifying privacy-type goals. Recently the tool noname was published that can automatically analyze specifications for a bounded number of sessions, but ships only with a few simple examples. This paper models two more complicated case studies, namely the ICAO 9303 BAC and the Privacy Authentication protocol by Abadi and Fournet, and applies the noname tool to analyze them, reproducing known vulnerabilities and verifying the corresponding fixes, as well as providing a better understanding of the privacy properties they provide