---
_id: '10865'
abstract:
- lang: eng
  text: "We introduce the notion of Witness Maps as a cryptographic notion of a proof
    system. A Unique Witness Map (UWM) deterministically maps all witnesses for an
    \  NP  statement to a single representative witness, resulting in a computationally
    sound, deterministic-prover, non-interactive witness independent proof system.
    A relaxation of UWM, called Compact Witness Map (CWM), maps all the witnesses
    to a small number of witnesses, resulting in a “lossy” deterministic-prover, non-interactive
    proof-system. We also define a Dual Mode Witness Map (DMWM) which adds an “extractable”
    mode to a CWM.\r\nOur main construction is a DMWM for all   NP  relations, assuming
    sub-exponentially secure indistinguishability obfuscation (  iO ), along with
    standard cryptographic assumptions. The DMWM construction relies on a CWM and
    a new primitive called Cumulative All-Lossy-But-One Trapdoor Functions (C-ALBO-TDF),
    both of which are in turn instantiated based on   iO  and other primitives. Our
    instantiation of a CWM is in fact a UWM; in turn, we show that a UWM implies Witness
    Encryption. Along the way to constructing UWM and C-ALBO-TDF, we also construct,
    from standard assumptions, Puncturable Digital Signatures and a new primitive
    called Cumulative Lossy Trapdoor Functions (C-LTDF). The former improves up on
    a construction of Bellare et al. (Eurocrypt 2016), who relied on sub-exponentially
    secure   iO  and sub-exponentially secure OWF.\r\nAs an application of our constructions,
    we show how to use a DMWM to construct the first leakage and tamper-resilient
    signatures with a deterministic signer, thereby solving a decade old open problem
    posed by Katz and Vaikunthanathan (Asiacrypt 2009), by Boyle, Segev and Wichs
    (Eurocrypt 2011), as well as by Faonio and Venturi (Asiacrypt 2016). Our construction
    achieves the optimal leakage rate of   1−o(1) ."
acknowledgement: We would like to thank the anonymous reviewers of PKC 2019 for their
  useful comments and suggestions. We thank Omer Paneth for pointing out to us the
  connection between Unique Witness Maps (UWM) and Witness encryption (WE). The first
  author would like to acknowledge Pandu Rangan for his involvement during the initial
  discussion phase of the project.
article_processing_charge: No
author:
- first_name: Suvradip
  full_name: Chakraborty, Suvradip
  id: B9CD0494-D033-11E9-B219-A439E6697425
  last_name: Chakraborty
- first_name: Manoj
  full_name: Prabhakaran, Manoj
  last_name: Prabhakaran
- first_name: Daniel
  full_name: Wichs, Daniel
  last_name: Wichs
citation:
  ama: 'Chakraborty S, Prabhakaran M, Wichs D. Witness maps and applications. In:
    Kiayias A, ed. <i>Public-Key Cryptography</i>. Vol 12110. LNCS. Cham: Springer
    Nature; 2020:220-246. doi:<a href="https://doi.org/10.1007/978-3-030-45374-9_8">10.1007/978-3-030-45374-9_8</a>'
  apa: 'Chakraborty, S., Prabhakaran, M., &#38; Wichs, D. (2020). Witness maps and
    applications. In A. Kiayias (Ed.), <i>Public-Key Cryptography</i> (Vol. 12110,
    pp. 220–246). Cham: Springer Nature. <a href="https://doi.org/10.1007/978-3-030-45374-9_8">https://doi.org/10.1007/978-3-030-45374-9_8</a>'
  chicago: 'Chakraborty, Suvradip, Manoj Prabhakaran, and Daniel Wichs. “Witness Maps
    and Applications.” In <i>Public-Key Cryptography</i>, edited by A Kiayias, 12110:220–46.
    LNCS. Cham: Springer Nature, 2020. <a href="https://doi.org/10.1007/978-3-030-45374-9_8">https://doi.org/10.1007/978-3-030-45374-9_8</a>.'
  ieee: 'S. Chakraborty, M. Prabhakaran, and D. Wichs, “Witness maps and applications,”
    in <i>Public-Key Cryptography</i>, vol. 12110, A. Kiayias, Ed. Cham: Springer
    Nature, 2020, pp. 220–246.'
  ista: 'Chakraborty S, Prabhakaran M, Wichs D. 2020.Witness maps and applications.
    In: Public-Key Cryptography. vol. 12110, 220–246.'
  mla: Chakraborty, Suvradip, et al. “Witness Maps and Applications.” <i>Public-Key
    Cryptography</i>, edited by A Kiayias, vol. 12110, Springer Nature, 2020, pp.
    220–46, doi:<a href="https://doi.org/10.1007/978-3-030-45374-9_8">10.1007/978-3-030-45374-9_8</a>.
  short: S. Chakraborty, M. Prabhakaran, D. Wichs, in:, A. Kiayias (Ed.), Public-Key
    Cryptography, Springer Nature, Cham, 2020, pp. 220–246.
date_created: 2022-03-18T11:35:51Z
date_published: 2020-04-29T00:00:00Z
date_updated: 2023-09-05T15:10:02Z
day: '29'
doi: 10.1007/978-3-030-45374-9_8
editor:
- first_name: A
  full_name: Kiayias, A
  last_name: Kiayias
intvolume: '     12110'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2020/090
month: '04'
oa: 1
oa_version: Preprint
page: 220-246
place: Cham
publication: Public-Key Cryptography
publication_identifier:
  eissn:
  - 1611-3349
  isbn:
  - '9783030453732'
  - '9783030453749'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
series_title: LNCS
status: public
title: Witness maps and applications
type: book_chapter
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 12110
year: '2020'
...
---
_id: '8339'
abstract:
- lang: eng
  text: "Discrete Gaussian distributions over lattices are central to lattice-based
    cryptography, and to the computational and mathematical aspects of lattices more
    broadly. The literature contains a wealth of useful theorems about the behavior
    of discrete Gaussians under convolutions and related operations. Yet despite their
    structural similarities, most of these theorems are formally incomparable, and
    their proofs tend to be monolithic and written nearly “from scratch,” making them
    unnecessarily hard to verify, understand, and extend.\r\nIn this work we present
    a modular framework for analyzing linear operations on discrete Gaussian distributions.
    The framework abstracts away the particulars of Gaussians, and usually reduces
    proofs to the choice of appropriate linear transformations and elementary linear
    algebra. To showcase the approach, we establish several general properties of
    discrete Gaussians, and show how to obtain all prior convolution theorems (along
    with some new ones) as straightforward corollaries. As another application, we
    describe a self-reduction for Learning With Errors (LWE) that uses a fixed number
    of samples to generate an unlimited number of additional ones (having somewhat
    larger error). The distinguishing features of our reduction are its simple analysis
    in our framework, and its exclusive use of discrete Gaussians without any loss
    in parameters relative to a prior mixed discrete-and-continuous approach.\r\nAs
    a contribution of independent interest, for subgaussian random matrices we prove
    a singular value concentration bound with explicitly stated constants, and we
    give tighter heuristics for specific distributions that are commonly used for
    generating lattice trapdoors. These bounds yield improvements in the concrete
    bit-security estimates for trapdoor lattice cryptosystems."
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Nicholas
  full_name: Genise, Nicholas
  last_name: Genise
- first_name: Daniele
  full_name: Micciancio, Daniele
  last_name: Micciancio
- first_name: Chris
  full_name: Peikert, Chris
  last_name: Peikert
- first_name: Michael
  full_name: Walter, Michael
  id: 488F98B0-F248-11E8-B48F-1D18A9856A87
  last_name: Walter
  orcid: 0000-0003-3186-2482
citation:
  ama: 'Genise N, Micciancio D, Peikert C, Walter M. Improved discrete Gaussian and
    subgaussian analysis for lattice cryptography. In: <i>23rd IACR International
    Conference on the Practice and Theory of Public-Key Cryptography</i>. Vol 12110.
    Springer Nature; 2020:623-651. doi:<a href="https://doi.org/10.1007/978-3-030-45374-9_21">10.1007/978-3-030-45374-9_21</a>'
  apa: 'Genise, N., Micciancio, D., Peikert, C., &#38; Walter, M. (2020). Improved
    discrete Gaussian and subgaussian analysis for lattice cryptography. In <i>23rd
    IACR International Conference on the Practice and Theory of Public-Key Cryptography</i>
    (Vol. 12110, pp. 623–651). Edinburgh, United Kingdom: Springer Nature. <a href="https://doi.org/10.1007/978-3-030-45374-9_21">https://doi.org/10.1007/978-3-030-45374-9_21</a>'
  chicago: Genise, Nicholas, Daniele Micciancio, Chris Peikert, and Michael Walter.
    “Improved Discrete Gaussian and Subgaussian Analysis for Lattice Cryptography.”
    In <i>23rd IACR International Conference on the Practice and Theory of Public-Key
    Cryptography</i>, 12110:623–51. Springer Nature, 2020. <a href="https://doi.org/10.1007/978-3-030-45374-9_21">https://doi.org/10.1007/978-3-030-45374-9_21</a>.
  ieee: N. Genise, D. Micciancio, C. Peikert, and M. Walter, “Improved discrete Gaussian
    and subgaussian analysis for lattice cryptography,” in <i>23rd IACR International
    Conference on the Practice and Theory of Public-Key Cryptography</i>, Edinburgh,
    United Kingdom, 2020, vol. 12110, pp. 623–651.
  ista: 'Genise N, Micciancio D, Peikert C, Walter M. 2020. Improved discrete Gaussian
    and subgaussian analysis for lattice cryptography. 23rd IACR International Conference
    on the Practice and Theory of Public-Key Cryptography. PKC: Public-Key Cryptography,
    LNCS, vol. 12110, 623–651.'
  mla: Genise, Nicholas, et al. “Improved Discrete Gaussian and Subgaussian Analysis
    for Lattice Cryptography.” <i>23rd IACR International Conference on the Practice
    and Theory of Public-Key Cryptography</i>, vol. 12110, Springer Nature, 2020,
    pp. 623–51, doi:<a href="https://doi.org/10.1007/978-3-030-45374-9_21">10.1007/978-3-030-45374-9_21</a>.
  short: N. Genise, D. Micciancio, C. Peikert, M. Walter, in:, 23rd IACR International
    Conference on the Practice and Theory of Public-Key Cryptography, Springer Nature,
    2020, pp. 623–651.
conference:
  end_date: 2020-05-07
  location: Edinburgh, United Kingdom
  name: 'PKC: Public-Key Cryptography'
  start_date: 2020-05-04
date_created: 2020-09-06T22:01:13Z
date_published: 2020-05-15T00:00:00Z
date_updated: 2023-02-23T13:31:06Z
day: '15'
department:
- _id: KrPi
doi: 10.1007/978-3-030-45374-9_21
ec_funded: 1
intvolume: '     12110'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2020/337
month: '05'
oa: 1
oa_version: Preprint
page: 623-651
project:
- _id: 258AA5B2-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '682815'
  name: Teaching Old Crypto New Tricks
publication: 23rd IACR International Conference on the Practice and Theory of Public-Key
  Cryptography
publication_identifier:
  eissn:
  - '16113349'
  isbn:
  - '9783030453732'
  issn:
  - '03029743'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Improved discrete Gaussian and subgaussian analysis for lattice cryptography
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 12110
year: '2020'
...
