Securing proof-of-stake blockchain protocols

Wenting Li, Sébastien Andreina, Jens Matthias Bohli, Ghassan Karame

    Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

    Abstract

    Proof-of-Stake (PoS) protocols have been actively researched for the past five years. PoS finds direct applicability in open blockchain platforms and has been seen as a strong candidate to replace the largely inefficient Proof of Work mechanism that is currently plugged in most existing open blockchains. Although a number of PoS variants have been proposed, these protocols suffer from a number of security shortcomings; for instance, most existing PoS variants suffer from the nothing at stake and the long range attacks which considerably degrade security in the blockchain. In this paper, we address these problems and we propose two PoS protocols that allow validators to generate at most one block at any given “height”—thus alleviating the problem of nothing at stake and preventing attackers from compromising accounts to mount long range attacks. Our first protocol leverages a dedicated digital signature scheme that reveals the identity of the validator if the validator attempts to work on multiple blocks at the same height. On the other hand, our second protocol leverages existing pervasive Trusted Execution Environments (TEEs) to limit the block generation requests by any given validator to a maximum of one at a given height. We analyze the security of our proposals and evaluate their performance by means of implementation; our evaluation results show that our proposals introduce tolerable overhead in the block generation and validation process when compared to existing PoS protocols.

    Original languageEnglish
    Title of host publicationData Privacy Management, Cryptocurrencies and Blockchain Technology - ESORICS 2017 International Workshops, DPM 2017 and CBT 2017, Proceedings
    PublisherSpringer Verlag
    Pages297-315
    Number of pages19
    Volume10436 LNCS
    ISBN (Print)9783319678153
    DOIs
    Publication statusPublished - 2017
    Event12th International Workshop on Data Privacy Management, DPM 2017 held in conjunction with 22nd European Symposium on Research in Computer Security, ESORICS 2017 and 1st International Workshop on Cryptocurrencies and Blockchain Technology, CBT 2017 - Oslo, Norway
    Duration: 14 Sept 201715 Sept 2017

    Publication series

    NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
    Volume10436 LNCS
    ISSN (Print)0302-9743
    ISSN (Electronic)1611-3349

    Other

    Other12th International Workshop on Data Privacy Management, DPM 2017 held in conjunction with 22nd European Symposium on Research in Computer Security, ESORICS 2017 and 1st International Workshop on Cryptocurrencies and Blockchain Technology, CBT 2017
    Country/TerritoryNorway
    CityOslo
    Period14/09/1715/09/17

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