---
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '22318'
abstract:
- lang: eng
  text: "Many intended uses of differential privacy involve a continual mechanism
    that is set up to run continuously\r\nover a long period of time, making more
    statistical releases as either queries come in or the dataset is updated.\r\nIn
    this paper, we give the first general treatment of privacy against adaptive adversaries
    for mechanisms that\r\nsupport dataset updates and a variety of queries, all arbitrarily
    interleaved. It also models a very general notion\r\nof neighboring, that includes
    both event-level and user-level privacy. We prove several concurrent composition\r\ntheorems
    for continual mechanisms, which ensure privacy even when an adversary can interleave
    its queries\r\nand dataset updates to the different composed mechanisms. Previous
    concurrent composition theorems for\r\ndifferential privacy were only for the
    case when the dataset is static, with no adaptive updates. We also give\r\nthe
    first interactive and continual generalizations of the “parallel composition theorem”
    for noninteractive\r\ndifferential privacy. Specifically, we show that the analogue
    of the noninteractive parallel composition theorem\r\nholds if either there are
    no adaptive dataset updates or each of the composed mechanisms satisfies pure\r\ndifferential
    privacy, but it fails to hold for composing approximately differentially private
    mechanisms with\r\ndataset updates. Thus, we prove a tight new composition theorem
    for this case. In addition, we prove concurrent\r\nfilter compositions theorems
    for the scenarios in which the privacy parameters are adaptively chosen. We\r\nextend
    these results to other measures of differential privacy, including Rényi DP and
    \U0001D453 -DP.\r\nWe then formalize a set of general conditions on a continual
    mechanism M that runs multiple continual submechanisms such that the privacy guarantees
    of M follow directly using the above concurrent composition\r\ntheorems on the
    sub-mechanisms, without further privacy loss. This enables us to give a simpler
    and modular\r\nprivacy analysis of a recent continual histogram mechanism of Henzinger,
    Sricharan, and Steiner. In the\r\ncase of approximate DP, ours is the first proof
    that shows that its privacy holds against adaptive adversaries.\r\nWe also provide
    a framework that simplifies the analysis of local differential privacy when the
    protocol\r\nincludes multi-round server-user interactions. Using this result,
    we simplify the privacy analysis of the core\r\ndecomposition protocol of Dhulipala,
    Henzinger, Li, Liu, Sricharan, and Zhu [5]."
acknowledgement: "1Salil Vadhan was supported by NSF grant BCS-2218803, a grant from
  the Sloan Foundation, and\r\na Simons Investigator Award. Work began while a Visiting
  Researcher at the Bocconi University\r\nDepartment of Computing Sciences, supported
  by Luca Trevisan’s ERC Project GA-834861.\r\n2Monika Henzinger and Roodabeh Safavi
  were supported by the European Research Council (ERC)\r\nunder the European Union’s
  Horizon 2020 research and innovation programme (Grant agreement\r\nNo. 101019564),
  and the Austrian Science Fund (FWF) under grants DOI 10.55776/Z422, DOI\r\n10.55776/I5982,
  and DOI 10.55776/P33775. For open access purposes, the author has applied a CC BY\r\npublic
  copyright license to any author-accepted manuscript version arising from this submission.\r\nViews
  and opinions expressed are however those of the author(s)\r\nonly and do not necessarily
  reflect those of the European Union\r\nor the European Research Council Executive
  Agency. Neither the\r\nEuropean Union nor the granting authority can be held responsible
  for them."
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Monika H
  full_name: Henzinger, Monika H
  id: 540c9bbd-f2de-11ec-812d-d04a5be85630
  last_name: Henzinger
  orcid: 0000-0002-5008-6530
- first_name: Roodabeh
  full_name: Safavi Hemami, Roodabeh
  id: 72ed2640-8972-11ed-ae7b-f9c81ec75154
  last_name: Safavi Hemami
- first_name: Salil
  full_name: Vadhan, Salil
  last_name: Vadhan
citation:
  ama: Henzinger M, Safavi Hemami R, Vadhan S. Concurrent composition for differentially
    private continual mechanisms. <i>Proceedings of the ACM on Management of Data</i>.
    2026;4(2):1-26. doi:<a href="https://doi.org/10.1145/3801895">10.1145/3801895</a>
  apa: Henzinger, M., Safavi Hemami, R., &#38; Vadhan, S. (2026). Concurrent composition
    for differentially private continual mechanisms. <i>Proceedings of the ACM on
    Management of Data</i>. Association for Computing Machinery. <a href="https://doi.org/10.1145/3801895">https://doi.org/10.1145/3801895</a>
  chicago: Henzinger, Monika, Roodabeh Safavi Hemami, and Salil Vadhan. “Concurrent
    Composition for Differentially Private Continual Mechanisms.” <i>Proceedings of
    the ACM on Management of Data</i>. Association for Computing Machinery, 2026.
    <a href="https://doi.org/10.1145/3801895">https://doi.org/10.1145/3801895</a>.
  ieee: M. Henzinger, R. Safavi Hemami, and S. Vadhan, “Concurrent composition for
    differentially private continual mechanisms,” <i>Proceedings of the ACM on Management
    of Data</i>, vol. 4, no. 2. Association for Computing Machinery, pp. 1–26, 2026.
  ista: Henzinger M, Safavi Hemami R, Vadhan S. 2026. Concurrent composition for differentially
    private continual mechanisms. Proceedings of the ACM on Management of Data. 4(2),
    1–26.
  mla: Henzinger, Monika, et al. “Concurrent Composition for Differentially Private
    Continual Mechanisms.” <i>Proceedings of the ACM on Management of Data</i>, vol.
    4, no. 2, Association for Computing Machinery, 2026, pp. 1–26, doi:<a href="https://doi.org/10.1145/3801895">10.1145/3801895</a>.
  short: M. Henzinger, R. Safavi Hemami, S. Vadhan, Proceedings of the ACM on Management
    of Data 4 (2026) 1–26.
corr_author: '1'
das_tickbox: '0'
date_created: 2026-07-13T14:59:14Z
date_published: 2026-06-01T00:00:00Z
date_updated: 2026-07-16T09:14:49Z
day: '01'
ddc:
- '000'
department:
- _id: MoHe
doi: 10.1145/3801895
ec_funded: 1
external_id:
  arxiv:
  - '2411.03299'
file:
- access_level: open_access
  checksum: c6c5e256d02b90682c0690c3bee94040
  content_type: application/pdf
  creator: dernst
  date_created: 2026-07-16T09:09:53Z
  date_updated: 2026-07-16T09:09:53Z
  file_id: '22345'
  file_name: 2026_ACMMgmtData_Henzinger.pdf
  file_size: 655405
  relation: main_file
  success: 1
file_date_updated: 2026-07-16T09:09:53Z
has_accepted_license: '1'
intvolume: '         4'
issue: '2'
keyword:
- differential privacy
- concurrent composition
- continual release
- continual observation
- data streaming
- continual mechanisms
- concurrent parallel composition
- concurrent filter composition
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 1-26
project:
- _id: bd9ca328-d553-11ed-ba76-dc4f890cfe62
  call_identifier: H2020
  grant_number: '101019564'
  name: The design and evaluation of modern fully dynamic data structures
- _id: bda196b2-d553-11ed-ba76-8e8ee6c21103
  grant_number: I05982
  name: Static and Dynamic Hierarchical Graph Decompositions
- _id: bd9e3a2e-d553-11ed-ba76-8aa684ce17fe
  grant_number: P33775
  name: Fast Algorithms for a Reactive Network Layer
- _id: 34def286-11ca-11ed-8bc3-da5948e1613c
  grant_number: Z00422
  name: Efficient algorithms
publication: Proceedings of the ACM on Management of Data
publication_identifier:
  issn:
  - 2836-6573
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: no
title: Concurrent composition for differentially private continual mechanisms
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 4
year: '2026'
...
