Search Results

Documents authored by Kelkar, Mahimna

Document
DOI: 10.4230/LIPIcs.AFT.2024.2
BoLD: Fast and Cheap Dispute Resolution

Authors: Mario M. Alvarez, Henry Arneson, Ben Berger, Lee Bousfield, Chris Buckland, Yafah Edelman, Edward W. Felten, Daniel Goldman, Raul Jordan, Mahimna Kelkar, Akaki Mamageishvili, Harry Ng, Aman Sanghi, Victor Shoup, and Terence Tsao

Published in: LIPIcs, Volume 316, 6th Conference on Advances in Financial Technologies (AFT 2024)

Abstract
BoLD is a new dispute resolution protocol that is designed to replace the originally deployed Arbitrum dispute resolution protocol. Unlike that protocol, BoLD is resistant to delay attacks. It achieves this resistance without a significant increase in onchain computation costs and with reduced staking costs.
Cite as

Mario M. Alvarez, Henry Arneson, Ben Berger, Lee Bousfield, Chris Buckland, Yafah Edelman, Edward W. Felten, Daniel Goldman, Raul Jordan, Mahimna Kelkar, Akaki Mamageishvili, Harry Ng, Aman Sanghi, Victor Shoup, and Terence Tsao. BoLD: Fast and Cheap Dispute Resolution. In 6th Conference on Advances in Financial Technologies (AFT 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 316, pp. 2:1-2:19, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{alvarez_et_al:LIPIcs.AFT.2024.2,
  author =	{Alvarez, Mario M. and Arneson, Henry and Berger, Ben and Bousfield, Lee and Buckland, Chris and Edelman, Yafah and Felten, Edward W. and Goldman, Daniel and Jordan, Raul and Kelkar, Mahimna and Mamageishvili, Akaki and Ng, Harry and Sanghi, Aman and Shoup, Victor and Tsao, Terence},
  title =	{{BoLD: Fast and Cheap Dispute Resolution}},
  booktitle =	{6th Conference on Advances in Financial Technologies (AFT 2024)},
  pages =	{2:1--2:19},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-345-4},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{316},
  editor =	{B\"{o}hme, Rainer and Kiffer, Lucianna},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2024.2},
  URN =		{urn:nbn:de:0030-drops-209389},
  doi =		{10.4230/LIPIcs.AFT.2024.2},
  annote =	{Keywords: Optimistic rollups, fraud proofs}
}
Document
DOI: 10.4230/LIPIcs.ITC.2024.6
Information-Theoretic Single-Server PIR in the Shuffle Model

Authors: Yuval Ishai, Mahimna Kelkar, Daniel Lee, and Yiping Ma

Published in: LIPIcs, Volume 304, 5th Conference on Information-Theoretic Cryptography (ITC 2024)

Abstract
We revisit the problem of private information retrieval (PIR) in the shuffle model, where queries can be made anonymously by multiple clients. We present the first single-server PIR protocol in this model that has sublinear per-client communication and information-theoretic security. Moreover, following one-time preprocessing on the server side, our protocol only requires sublinear per-client computation. Concretely, for every γ > 0, the protocol has O(n^{γ}) communication and computation costs per (stateless) client, with 1/poly(n) statistical security, assuming that a size-n database is simultaneously accessed by poly(n) clients. This should be contrasted with the recent breakthrough result of Lin, Mook, and Wichs (STOC 2023) on doubly efficient PIR in the standard model, which is (inherently) limited to computational security.
Cite as

Yuval Ishai, Mahimna Kelkar, Daniel Lee, and Yiping Ma. Information-Theoretic Single-Server PIR in the Shuffle Model. In 5th Conference on Information-Theoretic Cryptography (ITC 2024). Leibniz International Proceedings in Informatics (LIPIcs), Volume 304, pp. 6:1-6:23, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2024)

Copy BibTex To Clipboard

@InProceedings{ishai_et_al:LIPIcs.ITC.2024.6,
  author =	{Ishai, Yuval and Kelkar, Mahimna and Lee, Daniel and Ma, Yiping},
  title =	{{Information-Theoretic Single-Server PIR in the Shuffle Model}},
  booktitle =	{5th Conference on Information-Theoretic Cryptography (ITC 2024)},
  pages =	{6:1--6:23},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-333-1},
  ISSN =	{1868-8969},
  year =	{2024},
  volume =	{304},
  editor =	{Aggarwal, Divesh},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITC.2024.6},
  URN =		{urn:nbn:de:0030-drops-205142},
  doi =		{10.4230/LIPIcs.ITC.2024.6},
  annote =	{Keywords: Private information retrieval, Shuffle model}
}
Document
DOI: 10.4230/LIPIcs.AFT.2023.7
STROBE: Streaming Threshold Random Beacons

Authors: Donald Beaver, Konstantinos Chalkias, Mahimna Kelkar, Lefteris Kokoris-Kogias, Kevin Lewi, Ladi de Naurois, Valeria Nikolaenko, Arnab Roy, and Alberto Sonnino

Published in: LIPIcs, Volume 282, 5th Conference on Advances in Financial Technologies (AFT 2023)

Abstract
We revisit decentralized random beacons with a focus on practical distributed applications. Decentralized random beacons (Beaver and So, Eurocrypt'93) provide the functionality for n parties to generate an unpredictable sequence of bits in a way that cannot be biased, which is useful for any decentralized protocol requiring trusted randomness. Existing beacon constructions are highly inefficient in practical settings where protocol parties need to rejoin after crashes or disconnections, and more significantly where smart contracts may rely on arbitrary index points in high-volume streams. For this, we introduce a new notion of history-generating decentralized random beacons (HGDRBs). Roughly, the history-generation property of HGDRBs allows for previous beacon outputs to be efficiently generated knowing only the current value and the public key. At application layers, history-generation supports registering a sparser set of on-chain values if desired, so that apps like lotteries can utilize on-chain values without incurring high-frequency costs, enjoying all the benefits of DRBs implemented off-chain or with decoupled, special-purpose chains. Unlike rollups, HG is tailored specifically to recovering and verifying pseudorandom bit sequences and thus enjoys unique optimizations investigated in this work. We introduce STROBE: an efficient HGDRB construction which generalizes the original squaring-based RSA approach of Beaver and So. STROBE enjoys several useful properties that make it suited for practical applications that use beacons: 1) history-generating: it can regenerate and verify high-throughput beacon streams, supporting sparse (thus cost-effective) ledger entries; 2) concisely self-verifying: NIZK-free, with state and validation employing a single ring element; 3) eco-friendly: stake-based rather than work based; 4) unbounded: refresh-free, addressing limitations of Beaver and So; 5) delay-free: results are immediately available. 6) storage-efficient: the last beacon suffices to derive all past outputs, thus O(1) storage requirements for nodes serving the whole history.
Cite as

Donald Beaver, Konstantinos Chalkias, Mahimna Kelkar, Lefteris Kokoris-Kogias, Kevin Lewi, Ladi de Naurois, Valeria Nikolaenko, Arnab Roy, and Alberto Sonnino. STROBE: Streaming Threshold Random Beacons. In 5th Conference on Advances in Financial Technologies (AFT 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 282, pp. 7:1-7:16, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)

Copy BibTex To Clipboard

@InProceedings{beaver_et_al:LIPIcs.AFT.2023.7,
  author =	{Beaver, Donald and Chalkias, Konstantinos and Kelkar, Mahimna and Kokoris-Kogias, Lefteris and Lewi, Kevin and de Naurois, Ladi and Nikolaenko, Valeria and Roy, Arnab and Sonnino, Alberto},
  title =	{{STROBE: Streaming Threshold Random Beacons}},
  booktitle =	{5th Conference on Advances in Financial Technologies (AFT 2023)},
  pages =	{7:1--7:16},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-303-4},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{282},
  editor =	{Bonneau, Joseph and Weinberg, S. Matthew},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2023.7},
  URN =		{urn:nbn:de:0030-drops-191969},
  doi =		{10.4230/LIPIcs.AFT.2023.7},
  annote =	{Keywords: decentralized randomness, beacons, consensus, blockchain, lottery}
}
Document
DOI: 10.4230/LIPIcs.AFT.2023.23
Buying Time: Latency Racing vs. Bidding for Transaction Ordering

Authors: Akaki Mamageishvili, Mahimna Kelkar, Jan Christoph Schlegel, and Edward W. Felten

Published in: LIPIcs, Volume 282, 5th Conference on Advances in Financial Technologies (AFT 2023)

Abstract
We design TimeBoost: a practical transaction ordering policy for rollup sequencers that takes into account both transaction timestamps and bids; it works by creating a score from timestamps and bids, and orders transactions based on this score. TimeBoost is transaction-data-independent (i.e., can work with encrypted transactions) and supports low transaction finalization times similar to a first-come first-serve (FCFS or pure-latency) ordering policy. At the same time, it avoids the inefficient latency competition created by an FCFS policy. It further satisfies useful economic properties of first-price auctions that come with a pure-bidding policy. We show through rigorous economic analyses how TimeBoost allows players to compete on arbitrage opportunities in a way that results in better guarantees compared to both pure-latency and pure-bidding approaches.
Cite as

Akaki Mamageishvili, Mahimna Kelkar, Jan Christoph Schlegel, and Edward W. Felten. Buying Time: Latency Racing vs. Bidding for Transaction Ordering. In 5th Conference on Advances in Financial Technologies (AFT 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 282, pp. 23:1-23:22, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)

Copy BibTex To Clipboard

@InProceedings{mamageishvili_et_al:LIPIcs.AFT.2023.23,
  author =	{Mamageishvili, Akaki and Kelkar, Mahimna and Schlegel, Jan Christoph and Felten, Edward W.},
  title =	{{Buying Time: Latency Racing vs. Bidding for Transaction Ordering}},
  booktitle =	{5th Conference on Advances in Financial Technologies (AFT 2023)},
  pages =	{23:1--23:22},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-303-4},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{282},
  editor =	{Bonneau, Joseph and Weinberg, S. Matthew},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2023.23},
  URN =		{urn:nbn:de:0030-drops-192120},
  doi =		{10.4230/LIPIcs.AFT.2023.23},
  annote =	{Keywords: Transaction ordering, First-come-first-serve, First-price auctions}
}
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