--- _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: Proceedings of the 13th International Conference on Availability, Reliability and Security - ARES ’18. New York, NY, USA: ACM. doi:10.1145/3230833.3234517' 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 Proceedings of the 13th International Conference on Availability, Reliability and Security - ARES ’18. New York, NY, USA: ACM. https://doi.org/10.1145/3230833.3234517' 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={10.1145/3230833.3234517}, 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 Proceedings of the 13th International Conference on Availability, Reliability and Security - ARES ’18. New York, NY, USA: ACM, n.d. https://doi.org/10.1145/3230833.3234517.' ieee: K. Bemmann et al., “Fully-Featured Anonymous Credentials with Reputation System,” in Proceedings of the 13th International Conference on Availability, Reliability and Security - ARES ’18, Hamburg, Germany. mla: Bemmann, Kai, et al. “Fully-Featured Anonymous Credentials with Reputation System.” Proceedings of the 13th International Conference on Availability, Reliability and Security - ARES ’18, ACM, doi:10.1145/3230833.3234517. 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: Proceedings of the Sixth International Conference on Mathematical Aspects of Computer and Information Sciences (MACIS). LNCS. ; 2015:166-180. doi:10.1007/978-3-319-32859-1_14' apa: Blömer, J., Juhnke, J., & Löken, N. (2015). Short Group Signatures with Distributed Traceability. In Proceedings of the Sixth International Conference on Mathematical Aspects of Computer and Information Sciences (MACIS) (pp. 166–180). https://doi.org/10.1007/978-3-319-32859-1_14 bibtex: '@inproceedings{Blömer_Juhnke_Löken_2015, series={LNCS}, title={Short Group Signatures with Distributed Traceability}, DOI={10.1007/978-3-319-32859-1_14}, 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 Proceedings of the Sixth International Conference on Mathematical Aspects of Computer and Information Sciences (MACIS), 166–80. LNCS, 2015. https://doi.org/10.1007/978-3-319-32859-1_14. ieee: J. Blömer, J. Juhnke, and N. Löken, “Short Group Signatures with Distributed Traceability,” in Proceedings of the Sixth International Conference on Mathematical Aspects of Computer and Information Sciences (MACIS), 2015, pp. 166–180. mla: Blömer, Johannes, et al. “Short Group Signatures with Distributed Traceability.” Proceedings of the Sixth International Conference on Mathematical Aspects of Computer and Information Sciences (MACIS), 2015, pp. 166–80, doi:10.1007/978-3-319-32859-1_14. 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' ...