2 Search Results for "Sattath, Or"

Document
DOI: 10.4230/OASIcs.Tokenomics.2021.3
Tuning PoW with Hybrid Expenditure

Authors: Itay Tsabary, Alexander Spiegelman, and Ittay Eyal

Published in: OASIcs, Volume 97, 3rd International Conference on Blockchain Economics, Security and Protocols (Tokenomics 2021)

Abstract
Proof of Work (PoW) is a Sybil-deterrence security mechanism. It introduces an external cost to system participation by requiring computational effort to perform actions. However, since its inception, a central challenge was to tune this cost. Initial designs for deterring spam email and DoS attacks applied overhead equally to honest participants and attackers. Requiring too little effort does not deter attacks, whereas too much encumbers honest participation. This might be the reason it was never widely adopted. Nakamoto overcame this trade-off in Bitcoin by distinguishing desired from malicious behavior and introducing internal rewards for the former. This mechanism gained popularity in securing permissionless cryptocurrencies, using virtual internally-minted tokens for rewards. However, in existing blockchain protocols the internal rewards directly compensate users for (almost) the same value of external expenses. Thus, as the token value soars, so does the PoW expenditure. Bitcoin PoW, for example, already expends as much electricity as Colombia or Switzerland. This amount of resource-guzzling is unsustainable, and hinders even wider adoption of these systems. As such, a prominent alternative named Proof of Stake (PoS) replaces the expenditure requirement with token possession. However, PoS is shun by many cryptocurrency projects, as it is only secure under qualitatively-different assumptions, and the resultant systems are not permissionless. In this work we present Hybrid Expenditure Blockchain (HEB), a novel PoW mechanism. HEB is a generalization of Nakamoto’s protocol that enables tuning the external expenditure by introducing a complementary internal-expenditure mechanism. Thus, for the first time, HEB decouples external expenditure from the reward value. We show a practical parameter choice by which HEB requires significantly less external consumption compare to Nakamoto’s protocol, its resilience against rational attackers is similar, and it retains the decentralized and permissionless nature of the system. Taking the Bitcoin ecosystem as an example, HEB cuts the electricity consumption by half.
Cite as

Itay Tsabary, Alexander Spiegelman, and Ittay Eyal. Tuning PoW with Hybrid Expenditure. In 3rd International Conference on Blockchain Economics, Security and Protocols (Tokenomics 2021). Open Access Series in Informatics (OASIcs), Volume 97, pp. 3:1-3:17, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)

Copy BibTex To Clipboard

@InProceedings{tsabary_et_al:OASIcs.Tokenomics.2021.3,
  author =	{Tsabary, Itay and Spiegelman, Alexander and Eyal, Ittay},
  title =	{{Tuning PoW with Hybrid Expenditure}},
  booktitle =	{3rd International Conference on Blockchain Economics, Security and Protocols (Tokenomics 2021)},
  pages =	{3:1--3:17},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-220-4},
  ISSN =	{2190-6807},
  year =	{2022},
  volume =	{97},
  editor =	{Gramoli, Vincent and Halaburda, Hanna and Pass, Rafael},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops-dev.dagstuhl.de/entities/document/10.4230/OASIcs.Tokenomics.2021.3},
  URN =		{urn:nbn:de:0030-drops-159008},
  doi =		{10.4230/OASIcs.Tokenomics.2021.3},
  annote =	{Keywords: Blockchain, Proof of work, Cryptocurrency, Environmental impact}
}
Document
DOI: 10.4230/LIPIcs.TQC.2017.4
Quantum Coin Hedging, and a Counter Measure

Authors: Maor Ganz and Or Sattath

Published in: LIPIcs, Volume 73, 12th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2017)

Abstract
A quantum board game is a multi-round protocol between a single quantum player against the quantum board. Molina and Watrous discovered quantum hedging. They gave an example for perfect quantum hedging: a board game with winning probability < 1, such that the player can win with certainty at least 1-out-of-2 quantum board games played in parallel. Here we show that perfect quantum hedging occurs in a cryptographic protocol – quantum coin flipping. For this reason, when cryptographic protocols are composed in parallel, hedging may introduce serious challenges into their analysis. We also show that hedging cannot occur when playing two-outcome board games in sequence. This is done by showing a formula for the value of sequential two-outcome board games, which depends only on the optimal value of a single board game; this formula applies in a more general setting of possible target functions, in which hedging is only a special case.
Cite as

Maor Ganz and Or Sattath. Quantum Coin Hedging, and a Counter Measure. In 12th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2017). Leibniz International Proceedings in Informatics (LIPIcs), Volume 73, pp. 4:1-4:15, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2018)

Copy BibTex To Clipboard

@InProceedings{ganz_et_al:LIPIcs.TQC.2017.4,
  author =	{Ganz, Maor and Sattath, Or},
  title =	{{Quantum Coin Hedging, and a Counter Measure}},
  booktitle =	{12th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2017)},
  pages =	{4:1--4:15},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-034-7},
  ISSN =	{1868-8969},
  year =	{2018},
  volume =	{73},
  editor =	{Wilde, Mark M.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops-dev.dagstuhl.de/entities/document/10.4230/LIPIcs.TQC.2017.4},
  URN =		{urn:nbn:de:0030-drops-85767},
  doi =		{10.4230/LIPIcs.TQC.2017.4},
  annote =	{Keywords: quantum coin hedging, quantum board games}
}
  • Refine by Author
  • 1 Eyal, Ittay
  • 1 Ganz, Maor
  • 1 Sattath, Or
  • 1 Spiegelman, Alexander
  • 1 Tsabary, Itay

  • Refine by Classification
  • 1 Security and privacy → Distributed systems security

  • Refine by Keyword
  • 1 Blockchain
  • 1 Cryptocurrency
  • 1 Environmental impact
  • 1 Proof of work
  • 1 quantum board games
  • Show More...

  • Refine by Type
  • 2 document

  • Refine by Publication Year
  • 1 2018
  • 1 2022

Questions / Remarks / Feedback
X

Feedback for Dagstuhl Publishing


Thanks for your feedback!

Feedback submitted

Could not send message

Please try again later or send an E-mail
© 2023-2024 Schloss Dagstuhl – LZI GmbH Imprint Privacy Contact