---
_id: '12167'
abstract:
- lang: eng
  text: "Payment channels effectively move the transaction load off-chain thereby
    successfully addressing the inherent scalability problem most cryptocurrencies
    face. A major drawback of payment channels is the need to “top up” funds on-chain
    when a channel is depleted. Rebalancing was proposed to alleviate this issue,
    where parties with depleting channels move their funds along a cycle to replenish
    their channels off-chain. Protocols for rebalancing so far either introduce local
    solutions or compromise privacy.\r\nIn this work, we present an opt-in rebalancing
    protocol that is both private and globally optimal, meaning our protocol maximizes
    the total amount of rebalanced funds. We study rebalancing from the framework
    of linear programming. To obtain full privacy guarantees, we leverage multi-party
    computation in solving the linear program, which is executed by selected participants
    to maintain efficiency. Finally, we efficiently decompose the rebalancing solution
    into incentive-compatible cycles which conserve user balances when executed atomically."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Georgia
  full_name: Avarikioti, Georgia
  id: c20482a0-3b89-11eb-9862-88cf6404b88c
  last_name: Avarikioti
- first_name: Krzysztof Z
  full_name: Pietrzak, Krzysztof Z
  id: 3E04A7AA-F248-11E8-B48F-1D18A9856A87
  last_name: Pietrzak
  orcid: 0000-0002-9139-1654
- first_name: Iosif
  full_name: Salem, Iosif
  last_name: Salem
- first_name: Stefan
  full_name: Schmid, Stefan
  last_name: Schmid
- first_name: Samarth
  full_name: Tiwari, Samarth
  last_name: Tiwari
- first_name: Michelle X
  full_name: Yeo, Michelle X
  id: 2D82B818-F248-11E8-B48F-1D18A9856A87
  last_name: Yeo
citation:
  ama: 'Avarikioti G, Pietrzak KZ, Salem I, Schmid S, Tiwari S, Yeo MX. Hide &
    Seek: Privacy-preserving rebalancing on payment channel networks. In: <i>Financial
    Cryptography and Data Security</i>. Vol 13411. Springer Nature; 2022:358-373.
    doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_17">10.1007/978-3-031-18283-9_17</a>'
  apa: 'Avarikioti, G., Pietrzak, K. Z., Salem, I., Schmid, S., Tiwari, S., &#38;
    Yeo, M. X. (2022). Hide &#38; Seek: Privacy-preserving rebalancing on payment
    channel networks. In <i>Financial Cryptography and Data Security</i> (Vol. 13411,
    pp. 358–373). Grenada: Springer Nature. <a href="https://doi.org/10.1007/978-3-031-18283-9_17">https://doi.org/10.1007/978-3-031-18283-9_17</a>'
  chicago: 'Avarikioti, Georgia, Krzysztof Z Pietrzak, Iosif Salem, Stefan Schmid,
    Samarth Tiwari, and Michelle X Yeo. “Hide &#38; Seek: Privacy-Preserving Rebalancing
    on Payment Channel Networks.” In <i>Financial Cryptography and Data Security</i>,
    13411:358–73. Springer Nature, 2022. <a href="https://doi.org/10.1007/978-3-031-18283-9_17">https://doi.org/10.1007/978-3-031-18283-9_17</a>.'
  ieee: 'G. Avarikioti, K. Z. Pietrzak, I. Salem, S. Schmid, S. Tiwari, and M. X.
    Yeo, “Hide &#38; Seek: Privacy-preserving rebalancing on payment channel networks,”
    in <i>Financial Cryptography and Data Security</i>, Grenada, 2022, vol. 13411,
    pp. 358–373.'
  ista: 'Avarikioti G, Pietrzak KZ, Salem I, Schmid S, Tiwari S, Yeo MX. 2022. Hide
    &#38; Seek: Privacy-preserving rebalancing on payment channel networks. Financial
    Cryptography and Data Security. FC: Financial Cryptography and Data Security,
    LNCS, vol. 13411, 358–373.'
  mla: 'Avarikioti, Georgia, et al. “Hide &#38; Seek: Privacy-Preserving Rebalancing
    on Payment Channel Networks.” <i>Financial Cryptography and Data Security</i>,
    vol. 13411, Springer Nature, 2022, pp. 358–73, doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_17">10.1007/978-3-031-18283-9_17</a>.'
  short: G. Avarikioti, K.Z. Pietrzak, I. Salem, S. Schmid, S. Tiwari, M.X. Yeo, in:,
    Financial Cryptography and Data Security, Springer Nature, 2022, pp. 358–373.
conference:
  end_date: 2022-05-06
  location: Grenada
  name: 'FC: Financial Cryptography and Data Security'
  start_date: 2022-05-02
date_created: 2023-01-12T12:10:38Z
date_published: 2022-10-22T00:00:00Z
date_updated: 2023-09-05T15:10:57Z
day: '22'
department:
- _id: KrPi
doi: 10.1007/978-3-031-18283-9_17
external_id:
  arxiv:
  - '2110.08848'
intvolume: '     13411'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2110.08848
month: '10'
oa: 1
oa_version: Preprint
page: 358-373
publication: Financial Cryptography and Data Security
publication_identifier:
  eisbn:
  - '9783031182839'
  eissn:
  - 1611-3349
  isbn:
  - '9783031182822'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Hide & Seek: Privacy-preserving rebalancing on payment channel networks'
type: conference
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 13411
year: '2022'
...
---
_id: '12168'
abstract:
- lang: eng
  text: "Advances in blockchains have influenced the State-Machine-Replication (SMR)
    world and many state-of-the-art blockchain-SMR solutions are based on two pillars:
    Chaining and Leader-rotation. A predetermined round-robin mechanism used for Leader-rotation,
    however, has an undesirable behavior: crashed parties become designated leaders
    infinitely often, slowing down overall system performance. In this paper, we provide
    a new Leader-Aware SMR framework that, among other desirable properties, formalizes
    a Leader-utilization requirement that bounds the number of rounds whose leaders
    are faulty in crash-only executions.\r\nWe introduce Carousel, a novel, reputation-based
    Leader-rotation solution to achieve Leader-Aware SMR. The challenge in adaptive
    Leader-rotation is that it cannot rely on consensus to determine a leader, since
    consensus itself needs a leader. Carousel uses the available on-chain information
    to determine a leader locally and achieves Liveness despite this difficulty. A
    HotStuff implementation fitted with Carousel demonstrates drastic performance
    improvements: it increases throughput over 2x in faultless settings and provided
    a 20x throughput increase and 5x latency reduction in the presence of faults."
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Shir
  full_name: Cohen, Shir
  last_name: Cohen
- first_name: Rati
  full_name: Gelashvili, Rati
  last_name: Gelashvili
- first_name: Eleftherios
  full_name: Kokoris Kogias, Eleftherios
  id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
  last_name: Kokoris Kogias
- first_name: Zekun
  full_name: Li, Zekun
  last_name: Li
- first_name: Dahlia
  full_name: Malkhi, Dahlia
  last_name: Malkhi
- first_name: Alberto
  full_name: Sonnino, Alberto
  last_name: Sonnino
- first_name: Alexander
  full_name: Spiegelman, Alexander
  last_name: Spiegelman
citation:
  ama: 'Cohen S, Gelashvili R, Kokoris Kogias E, et al. Be aware of your leaders.
    In: <i>International Conference on Financial Cryptography and Data Security</i>.
    Vol 13411. Springer Nature; 2022:279-295. doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_13">10.1007/978-3-031-18283-9_13</a>'
  apa: 'Cohen, S., Gelashvili, R., Kokoris Kogias, E., Li, Z., Malkhi, D., Sonnino,
    A., &#38; Spiegelman, A. (2022). Be aware of your leaders. In <i>International
    Conference on Financial Cryptography and Data Security</i> (Vol. 13411, pp. 279–295).
    Grenada: Springer Nature. <a href="https://doi.org/10.1007/978-3-031-18283-9_13">https://doi.org/10.1007/978-3-031-18283-9_13</a>'
  chicago: Cohen, Shir, Rati Gelashvili, Eleftherios Kokoris Kogias, Zekun Li, Dahlia
    Malkhi, Alberto Sonnino, and Alexander Spiegelman. “Be Aware of Your Leaders.”
    In <i>International Conference on Financial Cryptography and Data Security</i>,
    13411:279–95. Springer Nature, 2022. <a href="https://doi.org/10.1007/978-3-031-18283-9_13">https://doi.org/10.1007/978-3-031-18283-9_13</a>.
  ieee: S. Cohen <i>et al.</i>, “Be aware of your leaders,” in <i>International Conference
    on Financial Cryptography and Data Security</i>, Grenada, 2022, vol. 13411, pp.
    279–295.
  ista: 'Cohen S, Gelashvili R, Kokoris Kogias E, Li Z, Malkhi D, Sonnino A, Spiegelman
    A. 2022. Be aware of your leaders. International Conference on Financial Cryptography
    and Data Security. FC: Financial Cryptography and Data Security, LNCS, vol. 13411,
    279–295.'
  mla: Cohen, Shir, et al. “Be Aware of Your Leaders.” <i>International Conference
    on Financial Cryptography and Data Security</i>, vol. 13411, Springer Nature,
    2022, pp. 279–95, doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_13">10.1007/978-3-031-18283-9_13</a>.
  short: S. Cohen, R. Gelashvili, E. Kokoris Kogias, Z. Li, D. Malkhi, A. Sonnino,
    A. Spiegelman, in:, International Conference on Financial Cryptography and Data
    Security, Springer Nature, 2022, pp. 279–295.
conference:
  end_date: 2022-05-06
  location: Grenada
  name: 'FC: Financial Cryptography and Data Security'
  start_date: 2022-05-02
date_created: 2023-01-12T12:10:49Z
date_published: 2022-10-22T00:00:00Z
date_updated: 2023-09-05T15:11:35Z
day: '22'
department:
- _id: ElKo
doi: 10.1007/978-3-031-18283-9_13
external_id:
  arxiv:
  - '2110.00960'
intvolume: '     13411'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2110.00960
month: '10'
oa: 1
oa_version: Preprint
page: 279-295
publication: International Conference on Financial Cryptography and Data Security
publication_identifier:
  eisbn:
  - '9783031182839'
  eissn:
  - 1611-3349
  isbn:
  - '9783031182822'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Be aware of your leaders
type: conference
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 13411
year: '2022'
...
---
_id: '12298'
abstract:
- lang: eng
  text: 'Existing committee-based Byzantine state machine replication (SMR) protocols,
    typically deployed in production blockchains, face a clear trade-off: (1) they
    either achieve linear communication cost in the steady state, but sacrifice liveness
    during periods of asynchrony, or (2) they are robust (progress with probability
    one) but pay quadratic communication cost. We believe this trade-off is unwarranted
    since existing linear protocols still have asymptotic quadratic cost in the worst
    case. We design Ditto, a Byzantine SMR protocol that enjoys the best of both worlds:
    optimal communication on and off the steady state (linear and quadratic, respectively)
    and progress guarantee under asynchrony and DDoS attacks. We achieve this by replacing
    the view-synchronization of partially synchronous protocols with an asynchronous
    fallback mechanism at no extra asymptotic cost. Specifically, we start from HotStuff,
    a state-of-the-art linear protocol, and gradually build Ditto. As a separate contribution
    and an intermediate step, we design a 2-chain version of HotStuff, Jolteon, which
    leverages a quadratic view-change mechanism to reduce the latency of the standard
    3-chain HotStuff. We implement and experimentally evaluate all our systems to
    prove that breaking the robustness-efficiency trade-off is in the realm of practicality.'
acknowledgement: We thank our shepherd Aniket Kate and the anonymous reviewers at
  FC 2022 for their helpful feedback. This work is supported by the Novi team at Facebook.
  We also thank the Novi Research and Engineering teams for valuable feedback, and
  in particular Mathieu Baudet, Andrey Chursin, George Danezis, Zekun Li, and Dahlia
  Malkhi for discussions that shaped this work.
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Rati
  full_name: Gelashvili, Rati
  last_name: Gelashvili
- first_name: Eleftherios
  full_name: Kokoris Kogias, Eleftherios
  id: f5983044-d7ef-11ea-ac6d-fd1430a26d30
  last_name: Kokoris Kogias
- first_name: Alberto
  full_name: Sonnino, Alberto
  last_name: Sonnino
- first_name: Alexander
  full_name: Spiegelman, Alexander
  last_name: Spiegelman
- first_name: Zhuolun
  full_name: Xiang, Zhuolun
  last_name: Xiang
citation:
  ama: 'Gelashvili R, Kokoris Kogias E, Sonnino A, Spiegelman A, Xiang Z. Jolteon
    and ditto: Network-adaptive efficient consensus with asynchronous fallback. In:
    <i>Financial Cryptography and Data Security</i>. Vol 13411. Springer Nature; 2022:296-315.
    doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_14">10.1007/978-3-031-18283-9_14</a>'
  apa: 'Gelashvili, R., Kokoris Kogias, E., Sonnino, A., Spiegelman, A., &#38; Xiang,
    Z. (2022). Jolteon and ditto: Network-adaptive efficient consensus with asynchronous
    fallback. In <i>Financial Cryptography and Data Security</i> (Vol. 13411, pp.
    296–315). Radisson Grenada Beach Resort, Grenada: Springer Nature. <a href="https://doi.org/10.1007/978-3-031-18283-9_14">https://doi.org/10.1007/978-3-031-18283-9_14</a>'
  chicago: 'Gelashvili, Rati, Eleftherios Kokoris Kogias, Alberto Sonnino, Alexander
    Spiegelman, and Zhuolun Xiang. “Jolteon and Ditto: Network-Adaptive Efficient
    Consensus with Asynchronous Fallback.” In <i>Financial Cryptography and Data Security</i>,
    13411:296–315. Springer Nature, 2022. <a href="https://doi.org/10.1007/978-3-031-18283-9_14">https://doi.org/10.1007/978-3-031-18283-9_14</a>.'
  ieee: 'R. Gelashvili, E. Kokoris Kogias, A. Sonnino, A. Spiegelman, and Z. Xiang,
    “Jolteon and ditto: Network-adaptive efficient consensus with asynchronous fallback,”
    in <i>Financial Cryptography and Data Security</i>, Radisson Grenada Beach Resort,
    Grenada, 2022, vol. 13411, pp. 296–315.'
  ista: 'Gelashvili R, Kokoris Kogias E, Sonnino A, Spiegelman A, Xiang Z. 2022. Jolteon
    and ditto: Network-adaptive efficient consensus with asynchronous fallback. Financial
    Cryptography and Data Security. FC: Financial Cryptography, LNCS, vol. 13411,
    296–315.'
  mla: 'Gelashvili, Rati, et al. “Jolteon and Ditto: Network-Adaptive Efficient Consensus
    with Asynchronous Fallback.” <i>Financial Cryptography and Data Security</i>,
    vol. 13411, Springer Nature, 2022, pp. 296–315, doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_14">10.1007/978-3-031-18283-9_14</a>.'
  short: R. Gelashvili, E. Kokoris Kogias, A. Sonnino, A. Spiegelman, Z. Xiang, in:,
    Financial Cryptography and Data Security, Springer Nature, 2022, pp. 296–315.
conference:
  end_date: 2022-05-06
  location: Radisson Grenada Beach Resort, Grenada
  name: 'FC: Financial Cryptography'
  start_date: 2022-05-02
date_created: 2023-01-16T10:05:51Z
date_published: 2022-10-22T00:00:00Z
date_updated: 2023-09-05T15:13:17Z
day: '22'
department:
- _id: ElKo
doi: 10.1007/978-3-031-18283-9_14
external_id:
  arxiv:
  - '2106.10362'
intvolume: '     13411'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: ' https://doi.org/10.48550/arXiv.2106.10362'
month: '10'
oa: 1
oa_version: Preprint
page: 296-315
publication: Financial Cryptography and Data Security
publication_identifier:
  eisbn:
  - '9783031182839'
  eissn:
  - 1611-3349
  isbn:
  - '9783031182822'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Jolteon and ditto: Network-adaptive efficient consensus with asynchronous
  fallback'
type: conference
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 13411
year: '2022'
...