TY - GEN
T1 - Securing proof-of-stake blockchain protocols
AU - Li, Wenting
AU - Andreina, Sébastien
AU - Bohli, Jens Matthias
AU - Karame, Ghassan
PY - 2017
Y1 - 2017
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85030172520&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-67816-0_17
DO - 10.1007/978-3-319-67816-0_17
M3 - Conference contribution
AN - SCOPUS:85030172520
SN - 9783319678153
VL - 10436 LNCS
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 297
EP - 315
BT - Data Privacy Management, Cryptocurrencies and Blockchain Technology - ESORICS 2017 International Workshops, DPM 2017 and CBT 2017, Proceedings
PB - Springer Verlag
T2 - 12th 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
Y2 - 14 September 2017 through 15 September 2017
ER -