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802 results · page 34 of 34
Tim Ruffing, Pedro Moreno-Sánchez, Aniket Kate
No abstract is available for this record.
Lear Bahack
A widespread security claim of the Bitcoin system, presented in the original Bitcoin white-paper, states that the security of the system is guaranteed as long as there is no attacker in possession of half or more of the total computational power used to maintain the system. This claim, however, is proved based on theoretically flawed assumptions. In the paper we analyze two kinds of attacks based on two theoretical flaws: the Block Discarding Attack and the Difficulty Raising Attack. We argue that the current theoretical limit of attacker's fraction of total computational power essential for the security of the system is in a sense not $\frac{1}{2}$ but a bit less than $\frac{1}{4}$, and outline proposals for protocol change that can raise this limit to be as close to $\frac{1}{2}$ as we want. The basic idea of the Block Discarding Attack has been noted as early as 2010, and lately was independently though-of and analyzed by both author of this paper and authors of a most recently pre-print published paper. We thus focus on the major differences of our analysis, and try to explain the unfortunate surprising coincidence. To the best of our knowledge, the second attack is presented here for the first time.
Yogesh Malhotra
No abstract is available for this record.
George Drosatos, Αιμιλία Τασίδου, Pavlos S. Efraimidis
No abstract is available for this record.
Hong Wang, Wei Shi
A public watermark detection scheme using verifiable secret sharing is proposed. It removes the expensive zero-knowledge interactive proofs and replaces the traditional trusted third party with a group of proxies. Moreover, the scheme is secure against sensitivity attacks and very efficient in terms of computation cost, the number of rounds and bandwidth required in the communications.
Hendrik Tews, Bart Jacobs
No abstract is available for this record.
Peter Y. A. Ryan
No abstract is available for this record.
Mehmet Tahir Sandıkkaya, Bülent Örencik
Many electronic voting systems, classified mainly as homomorphic cryptography based, mix-net based and blind signature based, appear after the eighties when zero knowledge proofs were introduced. The common ground for all these three systems is that none of them works without real time cryptologic calculations that should be held on a server. As far as known, the agent-based approach has not been used in a secure electronic voting system. In this study, an agent-based electronic voting schema, which does not contain real time calculations on the server side, is proposed. Conventional cryptologic methods are used in the proposed schema and some of the requirements of an electronic voting system are constructed within the schema. The schema seems quite secure if the used cryptologic methods and agents are secure. In this paper, proposed schema will be explained and compared with already known electronic voting systems.
Birgit Pfitzmann, Ahmad‐Reza Sadeghi
No abstract is available for this record.
Stefano D’Amiano, Giovanni Di Crescenzo
No abstract is available for this record.