Search Results

Documents authored by Saraph, Vikram


Document
An Empirical Study of Speculative Concurrency in Ethereum Smart Contracts

Authors: Vikram Saraph and Maurice Herlihy

Published in: OASIcs, Volume 71, International Conference on Blockchain Economics, Security and Protocols (Tokenomics 2019)


Abstract
We use historical data to estimate the potential benefit of speculative techniques for executing Ethereum smart contracts in parallel. We replay transaction traces of sampled blocks from the Ethereum blockchain over time, using a simple speculative execution engine. In this engine, miners attempt to execute all transactions in a block in parallel, rolling back those that cause data conflicts. Aborted transactions are then executed sequentially. Validators execute the same schedule as miners. We find that our speculative technique yields estimated speed-ups starting at about 8-fold in 2016, declining to about 2-fold at the end of 2017, where speed-up is measured using either gas costs or instruction counts. We also observe that a small set of contracts are responsible for many data conflicts resulting from speculative concurrent execution.

Cite as

Vikram Saraph and Maurice Herlihy. An Empirical Study of Speculative Concurrency in Ethereum Smart Contracts. In International Conference on Blockchain Economics, Security and Protocols (Tokenomics 2019). Open Access Series in Informatics (OASIcs), Volume 71, pp. 4:1-4:15, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2020)


Copy BibTex To Clipboard

@InProceedings{saraph_et_al:OASIcs.Tokenomics.2019.4,
  author =	{Saraph, Vikram and Herlihy, Maurice},
  title =	{{An Empirical Study of Speculative Concurrency in Ethereum Smart Contracts}},
  booktitle =	{International Conference on Blockchain Economics, Security and Protocols (Tokenomics 2019)},
  pages =	{4:1--4:15},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-108-5},
  ISSN =	{2190-6807},
  year =	{2020},
  volume =	{71},
  editor =	{Danos, Vincent and Herlihy, Maurice and Potop-Butucaru, Maria and Prat, Julien and Tucci-Piergiovanni, Sara},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.Tokenomics.2019.4},
  URN =		{urn:nbn:de:0030-drops-119684},
  doi =		{10.4230/OASIcs.Tokenomics.2019.4},
  annote =	{Keywords: Blockchains, Smart Contracts}
}
Document
The Relative Power of Composite Loop Agreement Tasks

Authors: Vikram Saraph and Maurice Herlihy

Published in: LIPIcs, Volume 46, 19th International Conference on Principles of Distributed Systems (OPODIS 2015)


Abstract
Loop agreement is a family of distributed tasks that includes set agreement and simplex agreement, and was used to prove the undecidability of wait-free solvability of distributed tasks by read/write memory. Herlihy and Rajsbaum defined the algebraic signature of a loop agreement task, which consists of a group and a distinguished element. They used the algebraic signature to characterize the relative power of loop agreement tasks. In particular, they showed that one task implements another exactly when there is a homomorphism between their respective signatures sending one loop to the other. In this paper, we extend the previous result by defining the composition of multiple loop agreement tasks to create a new one with the same combined power. We generalize the original algebraic characterization for relative power to compositions of tasks. In this way, we can think of loop agreement tasks in terms of their basic building blocks. We also investigate a category-theoretic perspective of loop agreement by defining a category of loops, showing that the algebraic signature is a functor, and proving that our definition of task composition is the "correct" one, in a categorical sense.

Cite as

Vikram Saraph and Maurice Herlihy. The Relative Power of Composite Loop Agreement Tasks. In 19th International Conference on Principles of Distributed Systems (OPODIS 2015). Leibniz International Proceedings in Informatics (LIPIcs), Volume 46, pp. 13:1-13:16, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2016)


Copy BibTex To Clipboard

@InProceedings{saraph_et_al:LIPIcs.OPODIS.2015.13,
  author =	{Saraph, Vikram and Herlihy, Maurice},
  title =	{{The Relative Power of Composite Loop Agreement Tasks}},
  booktitle =	{19th International Conference on Principles of Distributed Systems (OPODIS 2015)},
  pages =	{13:1--13:16},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-939897-98-9},
  ISSN =	{1868-8969},
  year =	{2016},
  volume =	{46},
  editor =	{Anceaume, Emmanuelle and Cachin, Christian and Potop-Butucaru, Maria},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.OPODIS.2015.13},
  URN =		{urn:nbn:de:0030-drops-66044},
  doi =		{10.4230/LIPIcs.OPODIS.2015.13},
  annote =	{Keywords: Distributed computing, loop agreement, task composition, topology}
}
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