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How does blockchain security dictate blockchain implementation?

Lewis-Pye, Andrew and Roughgarden, Tim (2021) How does blockchain security dictate blockchain implementation? In: CCS 2021 - Proceedings of the 2021 ACM SIGSAC Conference on Computer and Communications Security. Proceedings of the ACM Conference on Computer and Communications Security. ACM Press, USA, 1006 - 1019. ISBN 9781450384544

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Identification Number: 10.1145/3460120.3484752


Blockchain protocols come with a variety of security guarantees. For example, BFT-inspired protocols such as Algorand tend to be secure in the partially synchronous setting, while longest chain protocols like Bitcoin will normally require stronger synchronicity to be secure. Another fundamental distinction, directly relevant to scalability solutions such as sharding, is whether or not a single untrusted user is able to point to certificates, which provide incontrovertible proof of block confirmation. Algorand produces such certificates, while Bitcoin does not. Are these properties accidental? Or are they inherent consequences of the paradigm of protocol design? Our aim in this paper is to understand what, fundamentally, governs the nature of security for permissionless blockchain protocols. Using the framework developed in [12], we prove general results showing that these questions relate directly to properties of the user selection process, i.e. the method (such as proof-of-work or proof-of-stake) which is used to select users with the task of updating state. Our results suffice to establish, for example, that the production of certificates is impossible for proof-of-work protocols, but is automatic for standard forms of proof-of-stake protocols. As a byproduct of our work, we also define a number of security notions and identify the equivalences and inequivalences among them.

Item Type: Book Section
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Additional Information: © 2021 ACM, Inc
Divisions: Mathematics
Subjects: Q Science > QA Mathematics > QA75 Electronic computers. Computer science
Date Deposited: 06 Sep 2021 09:18
Last Modified: 23 May 2024 22:12

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