---
_id: '3265'
abstract:
- lang: eng
  text: "We present CLARC (Cryptographic Library for Anonymous Reputation and Credentials),
    an anonymous credentials system (ACS) combined with an anonymous reputation system.\r\n\r\nUsing
    CLARC, users can receive attribute-based credentials from issuers. They can efficiently
    prove that their credentials satisfy complex (access) policies in a privacy-preserving
    way. This implements anonymous access control with complex policies.\r\n\r\nFurthermore,
    CLARC is the first ACS that is combined with an anonymous reputation system where
    users can anonymously rate services. A user who gets access to a service via a
    credential, also anonymously receives a review token to rate the service. If a
    user creates more than a single rating, this can be detected by anyone, preventing
    users from spamming ratings to sway public opinion.\r\n\r\nTo evaluate feasibility
    of our construction, we present an open-source prototype implementation."
author:
- first_name: Kai
  full_name: Bemmann, Kai
  last_name: Bemmann
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Jan
  full_name: Bobolz, Jan
  id: '27207'
  last_name: Bobolz
- first_name: Henrik
  full_name: Bröcher, Henrik
  id: '41047'
  last_name: Bröcher
- first_name: Denis Pascal
  full_name: Diemert, Denis Pascal
  id: '44071'
  last_name: Diemert
- first_name: Fabian
  full_name: Eidens, Fabian
  id: '25078'
  last_name: Eidens
- first_name: Lukas
  full_name: Eilers, Lukas
  last_name: Eilers
- first_name: Jan Frederik
  full_name: Haltermann, Jan Frederik
  id: '44413'
  last_name: Haltermann
- first_name: Jakob
  full_name: Juhnke, Jakob
  id: '48090'
  last_name: Juhnke
- first_name: Burhan
  full_name: Otour, Burhan
  last_name: Otour
- first_name: Laurens Alexander
  full_name: Porzenheim, Laurens Alexander
  id: '47434'
  last_name: Porzenheim
- first_name: Simon
  full_name: Pukrop, Simon
  last_name: Pukrop
- first_name: Erik
  full_name: Schilling, Erik
  last_name: Schilling
- first_name: Michael
  full_name: Schlichtig, Michael
  id: '32312'
  last_name: Schlichtig
- first_name: Marcel
  full_name: Stienemeier, Marcel
  last_name: Stienemeier
citation:
  ama: 'Bemmann K, Blömer J, Bobolz J, et al. Fully-Featured Anonymous Credentials
    with Reputation System. In: <i>Proceedings of the 13th International Conference
    on Availability, Reliability and Security - ARES ’18</i>. New York, NY, USA: ACM.
    doi:<a href="https://doi.org/10.1145/3230833.3234517">10.1145/3230833.3234517</a>'
  apa: 'Bemmann, K., Blömer, J., Bobolz, J., Bröcher, H., Diemert, D. P., Eidens,
    F., … Stienemeier, M. (n.d.). Fully-Featured Anonymous Credentials with Reputation
    System. In <i>Proceedings of the 13th International Conference on Availability,
    Reliability and Security - ARES ’18</i>. New York, NY, USA: ACM. <a href="https://doi.org/10.1145/3230833.3234517">https://doi.org/10.1145/3230833.3234517</a>'
  bibtex: '@inproceedings{Bemmann_Blömer_Bobolz_Bröcher_Diemert_Eidens_Eilers_Haltermann_Juhnke_Otour_et
    al., place={New York, NY, USA}, title={Fully-Featured Anonymous Credentials with
    Reputation System}, DOI={<a href="https://doi.org/10.1145/3230833.3234517">10.1145/3230833.3234517</a>},
    booktitle={Proceedings of the 13th International Conference on Availability, Reliability
    and Security - ARES ’18}, publisher={ACM}, author={Bemmann, Kai and Blömer, Johannes
    and Bobolz, Jan and Bröcher, Henrik and Diemert, Denis Pascal and Eidens, Fabian
    and Eilers, Lukas and Haltermann, Jan Frederik and Juhnke, Jakob and Otour, Burhan
    and et al.} }'
  chicago: 'Bemmann, Kai, Johannes Blömer, Jan Bobolz, Henrik Bröcher, Denis Pascal
    Diemert, Fabian Eidens, Lukas Eilers, et al. “Fully-Featured Anonymous Credentials
    with Reputation System.” In <i>Proceedings of the 13th International Conference
    on Availability, Reliability and Security - ARES ’18</i>. New York, NY, USA: ACM,
    n.d. <a href="https://doi.org/10.1145/3230833.3234517">https://doi.org/10.1145/3230833.3234517</a>.'
  ieee: K. Bemmann <i>et al.</i>, “Fully-Featured Anonymous Credentials with Reputation
    System,” in <i>Proceedings of the 13th International Conference on Availability,
    Reliability and Security - ARES ’18</i>, Hamburg, Germany.
  mla: Bemmann, Kai, et al. “Fully-Featured Anonymous Credentials with Reputation
    System.” <i>Proceedings of the 13th International Conference on Availability,
    Reliability and Security - ARES ’18</i>, ACM, doi:<a href="https://doi.org/10.1145/3230833.3234517">10.1145/3230833.3234517</a>.
  short: 'K. Bemmann, J. Blömer, J. Bobolz, H. Bröcher, D.P. Diemert, F. Eidens, L.
    Eilers, J.F. Haltermann, J. Juhnke, B. Otour, L.A. Porzenheim, S. Pukrop, E. Schilling,
    M. Schlichtig, M. Stienemeier, in: Proceedings of the 13th International Conference
    on Availability, Reliability and Security - ARES ’18, ACM, New York, NY, USA,
    n.d.'
conference:
  end_date: 2018-08-30
  location: Hamburg, Germany
  name: ARES 2018 - SECPID
  start_date: 2018-08-27
date_created: 2018-06-14T11:19:29Z
date_updated: 2022-01-06T06:59:07Z
ddc:
- '000'
department:
- _id: '64'
doi: 10.1145/3230833.3234517
file:
- access_level: closed
  content_type: application/pdf
  creator: feidens
  date_created: 2018-11-08T10:17:39Z
  date_updated: 2018-11-08T10:17:39Z
  file_id: '5428'
  file_name: react_acs.pdf
  file_size: 920843
  relation: main_file
file_date_updated: 2018-11-08T10:17:39Z
has_accepted_license: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2018/835
oa: '1'
place: New York, NY, USA
project:
- _id: '1'
  name: SFB 901
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '13'
  name: SFB 901 - Subproject C1
- _id: '44'
  name: KogniHome - die mitdenkende Wohnung
publication: Proceedings of the 13th International Conference on Availability, Reliability
  and Security - ARES '18
publication_identifier:
  isbn:
  - 978-1-4503-6448-5
publication_status: accepted
publisher: ACM
quality_controlled: '1'
related_material:
  link:
  - relation: software
    url: https://github.com/upbcuk
status: public
title: Fully-Featured Anonymous Credentials with Reputation System
type: conference
user_id: '25078'
year: '2018'
...
---
_id: '253'
abstract:
- lang: eng
  text: Group signatures, introduced by Chaum and van Heyst [15], are an important
    primitive in cryptography. In group signature schemes every group member can anonymously
    sign messages on behalf of the group. In case of disputes a dedicated opening
    manager is able to trace signatures - he can extract the identity of the producer
    of a given signature. A formal model for static group signatures schemes and their
    security is defined by Bellare, Micciancio, and Warinschi [4], the case of dynamic
    groups is considered by Bellare, Shi, and Zhang [5]. Both models define group
    signature schemes with a single opening manager. The main difference between these
    models is that the number of group members in static schemes is fixed, while in
    dynamic schemes group members can join the group over time.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Jakob
  full_name: Juhnke, Jakob
  id: '48090'
  last_name: Juhnke
- first_name: Nils
  full_name: Löken, Nils
  id: '13703'
  last_name: Löken
citation:
  ama: 'Blömer J, Juhnke J, Löken N. Short Group Signatures with Distributed Traceability.
    In: <i>Proceedings of the Sixth International Conference on Mathematical Aspects
    of Computer and Information Sciences (MACIS)</i>. LNCS. ; 2015:166-180. doi:<a
    href="https://doi.org/10.1007/978-3-319-32859-1_14">10.1007/978-3-319-32859-1_14</a>'
  apa: Blömer, J., Juhnke, J., &#38; Löken, N. (2015). Short Group Signatures with
    Distributed Traceability. In <i>Proceedings of the Sixth International Conference
    on Mathematical Aspects of Computer and Information Sciences (MACIS)</i> (pp.
    166–180). <a href="https://doi.org/10.1007/978-3-319-32859-1_14">https://doi.org/10.1007/978-3-319-32859-1_14</a>
  bibtex: '@inproceedings{Blömer_Juhnke_Löken_2015, series={LNCS}, title={Short Group
    Signatures with Distributed Traceability}, DOI={<a href="https://doi.org/10.1007/978-3-319-32859-1_14">10.1007/978-3-319-32859-1_14</a>},
    booktitle={Proceedings of the Sixth International Conference on Mathematical Aspects
    of Computer and Information Sciences (MACIS)}, author={Blömer, Johannes and Juhnke,
    Jakob and Löken, Nils}, year={2015}, pages={166–180}, collection={LNCS} }'
  chicago: Blömer, Johannes, Jakob Juhnke, and Nils Löken. “Short Group Signatures
    with Distributed Traceability.” In <i>Proceedings of the Sixth International Conference
    on Mathematical Aspects of Computer and Information Sciences (MACIS)</i>, 166–80.
    LNCS, 2015. <a href="https://doi.org/10.1007/978-3-319-32859-1_14">https://doi.org/10.1007/978-3-319-32859-1_14</a>.
  ieee: J. Blömer, J. Juhnke, and N. Löken, “Short Group Signatures with Distributed
    Traceability,” in <i>Proceedings of the Sixth International Conference on Mathematical
    Aspects of Computer and Information Sciences (MACIS)</i>, 2015, pp. 166–180.
  mla: Blömer, Johannes, et al. “Short Group Signatures with Distributed Traceability.”
    <i>Proceedings of the Sixth International Conference on Mathematical Aspects of
    Computer and Information Sciences (MACIS)</i>, 2015, pp. 166–80, doi:<a href="https://doi.org/10.1007/978-3-319-32859-1_14">10.1007/978-3-319-32859-1_14</a>.
  short: 'J. Blömer, J. Juhnke, N. Löken, in: Proceedings of the Sixth International
    Conference on Mathematical Aspects of Computer and Information Sciences (MACIS),
    2015, pp. 166–180.'
date_created: 2017-10-17T12:41:41Z
date_updated: 2022-01-06T06:59:07Z
ddc:
- '000'
department:
- _id: '64'
doi: 10.1007/978-3-319-32859-1_14
file:
- access_level: closed
  content_type: application/pdf
  creator: ups
  date_created: 2018-11-02T14:08:23Z
  date_updated: 2018-11-02T14:08:23Z
  file_id: '5262'
  file_name: ShortGroupSignaturesWithDistri.pdf
  file_size: 262436
  relation: main_file
  success: 1
file_date_updated: 2018-11-02T14:08:23Z
has_accepted_license: '1'
language:
- iso: eng
page: 166-180
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '44'
  name: KogniHome - die mitdenkende Wohnung
publication: Proceedings of the Sixth International Conference on Mathematical Aspects
  of Computer and Information Sciences (MACIS)
related_material:
  record:
  - id: '325'
    relation: other
    status: public
series_title: LNCS
status: public
title: Short Group Signatures with Distributed Traceability
type: conference
user_id: '13703'
year: '2015'
...