---
_id: '2344'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
- first_name: Volker
  full_name: Krummel, Volker
  last_name: Krummel
- first_name: Nils
  full_name: Löken, Nils
  id: '13703'
  last_name: Löken
citation:
  ama: 'Blömer J, Günther P, Krummel V, Löken N. Attribute-Based Encryption as a Service
    for Access Control in Large-Scale Organizations. In: <i>Foundations and Practice
    of Security</i>. Cham: Springer International Publishing; 2017:3-17. doi:<a href="https://doi.org/10.1007/978-3-319-75650-9_1">10.1007/978-3-319-75650-9_1</a>'
  apa: 'Blömer, J., Günther, P., Krummel, V., &#38; Löken, N. (2017). Attribute-Based
    Encryption as a Service for Access Control in Large-Scale Organizations. In <i>Foundations
    and Practice of Security</i> (pp. 3–17). Cham: Springer International Publishing.
    <a href="https://doi.org/10.1007/978-3-319-75650-9_1">https://doi.org/10.1007/978-3-319-75650-9_1</a>'
  bibtex: '@inproceedings{Blömer_Günther_Krummel_Löken_2017, place={Cham}, title={Attribute-Based
    Encryption as a Service for Access Control in Large-Scale Organizations}, DOI={<a
    href="https://doi.org/10.1007/978-3-319-75650-9_1">10.1007/978-3-319-75650-9_1</a>},
    booktitle={Foundations and Practice of Security}, publisher={Springer International
    Publishing}, author={Blömer, Johannes and Günther, Peter and Krummel, Volker and
    Löken, Nils}, year={2017}, pages={3–17} }'
  chicago: 'Blömer, Johannes, Peter Günther, Volker Krummel, and Nils Löken. “Attribute-Based
    Encryption as a Service for Access Control in Large-Scale Organizations.” In <i>Foundations
    and Practice of Security</i>, 3–17. Cham: Springer International Publishing, 2017.
    <a href="https://doi.org/10.1007/978-3-319-75650-9_1">https://doi.org/10.1007/978-3-319-75650-9_1</a>.'
  ieee: J. Blömer, P. Günther, V. Krummel, and N. Löken, “Attribute-Based Encryption
    as a Service for Access Control in Large-Scale Organizations,” in <i>Foundations
    and Practice of Security</i>, 2017, pp. 3–17.
  mla: Blömer, Johannes, et al. “Attribute-Based Encryption as a Service for Access
    Control in Large-Scale Organizations.” <i>Foundations and Practice of Security</i>,
    Springer International Publishing, 2017, pp. 3–17, doi:<a href="https://doi.org/10.1007/978-3-319-75650-9_1">10.1007/978-3-319-75650-9_1</a>.
  short: 'J. Blömer, P. Günther, V. Krummel, N. Löken, in: Foundations and Practice
    of Security, Springer International Publishing, Cham, 2017, pp. 3–17.'
date_created: 2018-04-13T11:40:48Z
date_updated: 2022-01-06T06:55:55Z
ddc:
- '000'
department:
- _id: '64'
doi: 10.1007/978-3-319-75650-9_1
file:
- access_level: closed
  content_type: application/pdf
  creator: ups
  date_created: 2018-11-02T15:04:13Z
  date_updated: 2018-11-02T15:04:13Z
  file_id: '5292'
  file_name: Attribute-BasedEncryptionAsASe.pdf
  file_size: 634736
  relation: main_file
  success: 1
- access_level: open_access
  content_type: application/pdf
  creator: nilo
  date_created: 2018-11-08T09:53:34Z
  date_updated: 2018-11-08T09:53:34Z
  file_id: '5425'
  file_name: abe_aas.pdf
  file_size: 522516
  relation: main_file
file_date_updated: 2018-11-08T09:53:34Z
has_accepted_license: '1'
language:
- iso: eng
oa: '1'
page: 3-17
place: Cham
project:
- _id: '13'
  name: SFB 901 - Subproject C1
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '1'
  name: SFB 901
- _id: '43'
  name: Securing the Financial Cloud
publication: Foundations and Practice of Security
publication_identifier:
  isbn:
  - '9783319756493'
  - '9783319756509'
  issn:
  - 0302-9743
  - 1611-3349
publication_status: published
publisher: Springer International Publishing
status: public
title: Attribute-Based Encryption as a Service for Access Control in Large-Scale Organizations
type: conference
user_id: '13703'
year: '2017'
...
---
_id: '2947'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
citation:
  ama: 'Blömer J, Günther P. Singular Curve Point Decompression Attack. In: <i>2015
    Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC)</i>. IEEE; 2016.
    doi:<a href="https://doi.org/10.1109/fdtc.2015.17">10.1109/fdtc.2015.17</a>'
  apa: Blömer, J., &#38; Günther, P. (2016). Singular Curve Point Decompression Attack.
    In <i>2015 Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC)</i>.
    IEEE. <a href="https://doi.org/10.1109/fdtc.2015.17">https://doi.org/10.1109/fdtc.2015.17</a>
  bibtex: '@inproceedings{Blömer_Günther_2016, title={Singular Curve Point Decompression
    Attack}, DOI={<a href="https://doi.org/10.1109/fdtc.2015.17">10.1109/fdtc.2015.17</a>},
    booktitle={2015 Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC)},
    publisher={IEEE}, author={Blömer, Johannes and Günther, Peter}, year={2016} }'
  chicago: Blömer, Johannes, and Peter Günther. “Singular Curve Point Decompression
    Attack.” In <i>2015 Workshop on Fault Diagnosis and Tolerance in Cryptography
    (FDTC)</i>. IEEE, 2016. <a href="https://doi.org/10.1109/fdtc.2015.17">https://doi.org/10.1109/fdtc.2015.17</a>.
  ieee: J. Blömer and P. Günther, “Singular Curve Point Decompression Attack,” in
    <i>2015 Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC)</i>,
    2016.
  mla: Blömer, Johannes, and Peter Günther. “Singular Curve Point Decompression Attack.”
    <i>2015 Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC)</i>,
    IEEE, 2016, doi:<a href="https://doi.org/10.1109/fdtc.2015.17">10.1109/fdtc.2015.17</a>.
  short: 'J. Blömer, P. Günther, in: 2015 Workshop on Fault Diagnosis and Tolerance
    in Cryptography (FDTC), IEEE, 2016.'
date_created: 2018-05-29T11:25:43Z
date_updated: 2022-01-06T06:58:48Z
department:
- _id: '64'
doi: 10.1109/fdtc.2015.17
project:
- _id: '43'
  name: Securing the Financial Cloud
publication: 2015 Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC)
publication_identifier:
  isbn:
  - '9781467375795'
publication_status: published
publisher: IEEE
status: public
title: Singular Curve Point Decompression Attack
type: conference
user_id: '25078'
year: '2016'
...
---
_id: '2968'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Christiane
  full_name: Lammersen, Christiane
  last_name: Lammersen
- first_name: Melanie
  full_name: Schmidt, Melanie
  last_name: Schmidt
- first_name: Christian
  full_name: Sohler, Christian
  last_name: Sohler
citation:
  ama: 'Blömer J, Lammersen C, Schmidt M, Sohler C. Theoretical Analysis of the k-Means
    Algorithm – A Survey. In: <i>Algorithm Engineering</i>. Cham: Springer International
    Publishing; 2016:81-116. doi:<a href="https://doi.org/10.1007/978-3-319-49487-6_3">10.1007/978-3-319-49487-6_3</a>'
  apa: 'Blömer, J., Lammersen, C., Schmidt, M., &#38; Sohler, C. (2016). Theoretical
    Analysis of the k-Means Algorithm – A Survey. In <i>Algorithm Engineering</i>
    (pp. 81–116). Cham: Springer International Publishing. <a href="https://doi.org/10.1007/978-3-319-49487-6_3">https://doi.org/10.1007/978-3-319-49487-6_3</a>'
  bibtex: '@inbook{Blömer_Lammersen_Schmidt_Sohler_2016, place={Cham}, title={Theoretical
    Analysis of the k-Means Algorithm – A Survey}, DOI={<a href="https://doi.org/10.1007/978-3-319-49487-6_3">10.1007/978-3-319-49487-6_3</a>},
    booktitle={Algorithm Engineering}, publisher={Springer International Publishing},
    author={Blömer, Johannes and Lammersen, Christiane and Schmidt, Melanie and Sohler,
    Christian}, year={2016}, pages={81–116} }'
  chicago: 'Blömer, Johannes, Christiane Lammersen, Melanie Schmidt, and Christian
    Sohler. “Theoretical Analysis of the K-Means Algorithm – A Survey.” In <i>Algorithm
    Engineering</i>, 81–116. Cham: Springer International Publishing, 2016. <a href="https://doi.org/10.1007/978-3-319-49487-6_3">https://doi.org/10.1007/978-3-319-49487-6_3</a>.'
  ieee: 'J. Blömer, C. Lammersen, M. Schmidt, and C. Sohler, “Theoretical Analysis
    of the k-Means Algorithm – A Survey,” in <i>Algorithm Engineering</i>, Cham: Springer
    International Publishing, 2016, pp. 81–116.'
  mla: Blömer, Johannes, et al. “Theoretical Analysis of the K-Means Algorithm – A
    Survey.” <i>Algorithm Engineering</i>, Springer International Publishing, 2016,
    pp. 81–116, doi:<a href="https://doi.org/10.1007/978-3-319-49487-6_3">10.1007/978-3-319-49487-6_3</a>.
  short: 'J. Blömer, C. Lammersen, M. Schmidt, C. Sohler, in: Algorithm Engineering,
    Springer International Publishing, Cham, 2016, pp. 81–116.'
date_created: 2018-06-04T12:22:40Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
doi: 10.1007/978-3-319-49487-6_3
page: 81-116
place: Cham
publication: Algorithm Engineering
publication_identifier:
  isbn:
  - '9783319494869'
  - '9783319494876'
  issn:
  - 0302-9743
  - 1611-3349
publication_status: published
publisher: Springer International Publishing
status: public
title: Theoretical Analysis of the k-Means Algorithm – A Survey
type: book_chapter
user_id: '25078'
year: '2016'
...
---
_id: '2969'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Sascha
  full_name: Brauer, Sascha
  id: '13291'
  last_name: Brauer
- first_name: Kathrin
  full_name: Bujna, Kathrin
  last_name: Bujna
citation:
  ama: Blömer J, Brauer S, Bujna K. Hard-Clustering with Gaussian Mixture Models.
    2016.
  apa: Blömer, J., Brauer, S., &#38; Bujna, K. (2016). Hard-Clustering with Gaussian
    Mixture Models. Computing Research Repository.
  bibtex: '@article{Blömer_Brauer_Bujna_2016, title={Hard-Clustering with Gaussian
    Mixture Models}, publisher={Computing Research Repository}, author={Blömer, Johannes
    and Brauer, Sascha and Bujna, Kathrin}, year={2016} }'
  chicago: Blömer, Johannes, Sascha Brauer, and Kathrin Bujna. “Hard-Clustering with
    Gaussian Mixture Models.” Computing Research Repository, 2016.
  ieee: J. Blömer, S. Brauer, and K. Bujna, “Hard-Clustering with Gaussian Mixture
    Models.” Computing Research Repository, 2016.
  mla: Blömer, Johannes, et al. <i>Hard-Clustering with Gaussian Mixture Models</i>.
    Computing Research Repository, 2016.
  short: J. Blömer, S. Brauer, K. Bujna, (2016).
date_created: 2018-06-04T12:26:51Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1603.06478
oa: '1'
publisher: Computing Research Repository
status: public
title: Hard-Clustering with Gaussian Mixture Models
type: preprint
user_id: '25078'
year: '2016'
...
---
_id: '2970'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Kathrin
  full_name: Bujna, Kathrin
  last_name: Bujna
citation:
  ama: 'Blömer J, Bujna K. Adaptive Seeding for Gaussian Mixture Models. In: <i>Advances
    in Knowledge Discovery and Data Mining</i>. Cham: Springer International Publishing;
    2016:296-308. doi:<a href="https://doi.org/10.1007/978-3-319-31750-2_24">10.1007/978-3-319-31750-2_24</a>'
  apa: 'Blömer, J., &#38; Bujna, K. (2016). Adaptive Seeding for Gaussian Mixture
    Models. In <i>Advances in Knowledge Discovery and Data Mining</i> (pp. 296–308).
    Cham: Springer International Publishing. <a href="https://doi.org/10.1007/978-3-319-31750-2_24">https://doi.org/10.1007/978-3-319-31750-2_24</a>'
  bibtex: '@inbook{Blömer_Bujna_2016, place={Cham}, title={Adaptive Seeding for Gaussian
    Mixture Models}, DOI={<a href="https://doi.org/10.1007/978-3-319-31750-2_24">10.1007/978-3-319-31750-2_24</a>},
    booktitle={Advances in Knowledge Discovery and Data Mining}, publisher={Springer
    International Publishing}, author={Blömer, Johannes and Bujna, Kathrin}, year={2016},
    pages={296–308} }'
  chicago: 'Blömer, Johannes, and Kathrin Bujna. “Adaptive Seeding for Gaussian Mixture
    Models.” In <i>Advances in Knowledge Discovery and Data Mining</i>, 296–308. Cham:
    Springer International Publishing, 2016. <a href="https://doi.org/10.1007/978-3-319-31750-2_24">https://doi.org/10.1007/978-3-319-31750-2_24</a>.'
  ieee: 'J. Blömer and K. Bujna, “Adaptive Seeding for Gaussian Mixture Models,” in
    <i>Advances in Knowledge Discovery and Data Mining</i>, Cham: Springer International
    Publishing, 2016, pp. 296–308.'
  mla: Blömer, Johannes, and Kathrin Bujna. “Adaptive Seeding for Gaussian Mixture
    Models.” <i>Advances in Knowledge Discovery and Data Mining</i>, Springer International
    Publishing, 2016, pp. 296–308, doi:<a href="https://doi.org/10.1007/978-3-319-31750-2_24">10.1007/978-3-319-31750-2_24</a>.
  short: 'J. Blömer, K. Bujna, in: Advances in Knowledge Discovery and Data Mining,
    Springer International Publishing, Cham, 2016, pp. 296–308.'
date_created: 2018-06-04T12:27:21Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
doi: 10.1007/978-3-319-31750-2_24
page: 296-308
place: Cham
publication: Advances in Knowledge Discovery and Data Mining
publication_identifier:
  isbn:
  - '9783319317496'
  - '9783319317502'
  issn:
  - 0302-9743
  - 1611-3349
publication_status: published
publisher: Springer International Publishing
status: public
title: Adaptive Seeding for Gaussian Mixture Models
type: book_chapter
user_id: '25078'
year: '2016'
...
---
_id: '2971'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
citation:
  ama: Blömer J, Günther P. <i>Effizienz Und Sicherheit Paarungsbasierter Kryptographie</i>.
    Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops; 2016.
  apa: Blömer, J., &#38; Günther, P. (2016). <i>Effizienz und Sicherheit paarungsbasierter
    Kryptographie</i>. Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops.
  bibtex: '@book{Blömer_Günther_2016, title={Effizienz und Sicherheit paarungsbasierter
    Kryptographie}, publisher={Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops},
    author={Blömer, Johannes and Günther, Peter}, year={2016} }'
  chicago: Blömer, Johannes, and Peter Günther. <i>Effizienz Und Sicherheit Paarungsbasierter
    Kryptographie</i>. Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops, 2016.
  ieee: J. Blömer and P. Günther, <i>Effizienz und Sicherheit paarungsbasierter Kryptographie</i>.
    Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops, 2016.
  mla: Blömer, Johannes, and Peter Günther. <i>Effizienz Und Sicherheit Paarungsbasierter
    Kryptographie</i>. Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops, 2016.
  short: J. Blömer, P. Günther, Effizienz Und Sicherheit Paarungsbasierter Kryptographie,
    Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops, 2016.
date_created: 2018-06-05T07:21:25Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
publication_status: published
publisher: Tagungsband des 26. Fraunhofer SIT Smartcard-Workshops
status: public
title: Effizienz und Sicherheit paarungsbasierter Kryptographie
type: report
user_id: '25078'
year: '2016'
...
---
_id: '2367'
abstract:
- lang: eng
  text: One of the most popular fuzzy clustering techniques is the fuzzy K-means algorithm
    (also known as fuzzy-c-means or FCM algorithm). In contrast to the K-means and
    K-median problem, the underlying fuzzy K-means problem has not been studied from
    a theoretical point of view. In particular, there are no algorithms with approximation
    guarantees similar to the famous K-means++ algorithm known for the fuzzy K-means
    problem. This work initiates the study of the fuzzy K-means problem from an algorithmic
    and complexity theoretic perspective. We show that optimal solutions for the fuzzy
    K-means problem cannot, in general, be expressed by radicals over the input points.
    Surprisingly, this already holds for simple inputs in one-dimensional space. Hence,
    one cannot expect to compute optimal solutions exactly. We give the first (1+eps)-approximation
    algorithms for the fuzzy K-means problem. First, we present a deterministic approximation
    algorithm whose runtime is polynomial in N and linear in the dimension D of the
    input set, given that K is constant, i.e. a polynomial time approximation scheme
    (PTAS) for fixed K. We achieve this result by showing that for each soft clustering
    there exists a hard clustering with similar properties. Second, by using techniques
    known from coreset constructions for the K-means problem, we develop a deterministic
    approximation algorithm that runs in time almost linear in N but exponential in
    the dimension D. We complement these results with a randomized algorithm which
    imposes some natural restrictions on the sought solution and whose runtime is
    comparable to some of the most efficient approximation algorithms for K-means,
    i.e. linear in the number of points and the dimension, but exponential in the
    number of clusters.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Sascha
  full_name: Brauer, Sascha
  id: '13291'
  last_name: Brauer
- first_name: Kathrin
  full_name: Bujna, Kathrin
  last_name: Bujna
citation:
  ama: 'Blömer J, Brauer S, Bujna K. A Theoretical Analysis of the Fuzzy K-Means Problem.
    In: <i>2016 IEEE 16th International Conference on Data Mining (ICDM)</i>. IEEE;
    2016:805-810. doi:<a href="https://doi.org/10.1109/icdm.2016.0094">10.1109/icdm.2016.0094</a>'
  apa: 'Blömer, J., Brauer, S., &#38; Bujna, K. (2016). A Theoretical Analysis of
    the Fuzzy K-Means Problem. In <i>2016 IEEE 16th International Conference on Data
    Mining (ICDM)</i> (pp. 805–810). Barcelona, Spain: IEEE. <a href="https://doi.org/10.1109/icdm.2016.0094">https://doi.org/10.1109/icdm.2016.0094</a>'
  bibtex: '@inproceedings{Blömer_Brauer_Bujna_2016, title={A Theoretical Analysis
    of the Fuzzy K-Means Problem}, DOI={<a href="https://doi.org/10.1109/icdm.2016.0094">10.1109/icdm.2016.0094</a>},
    booktitle={2016 IEEE 16th International Conference on Data Mining (ICDM)}, publisher={IEEE},
    author={Blömer, Johannes and Brauer, Sascha and Bujna, Kathrin}, year={2016},
    pages={805–810} }'
  chicago: Blömer, Johannes, Sascha Brauer, and Kathrin Bujna. “A Theoretical Analysis
    of the Fuzzy K-Means Problem.” In <i>2016 IEEE 16th International Conference on
    Data Mining (ICDM)</i>, 805–10. IEEE, 2016. <a href="https://doi.org/10.1109/icdm.2016.0094">https://doi.org/10.1109/icdm.2016.0094</a>.
  ieee: J. Blömer, S. Brauer, and K. Bujna, “A Theoretical Analysis of the Fuzzy K-Means
    Problem,” in <i>2016 IEEE 16th International Conference on Data Mining (ICDM)</i>,
    Barcelona, Spain, 2016, pp. 805–810.
  mla: Blömer, Johannes, et al. “A Theoretical Analysis of the Fuzzy K-Means Problem.”
    <i>2016 IEEE 16th International Conference on Data Mining (ICDM)</i>, IEEE, 2016,
    pp. 805–10, doi:<a href="https://doi.org/10.1109/icdm.2016.0094">10.1109/icdm.2016.0094</a>.
  short: 'J. Blömer, S. Brauer, K. Bujna, in: 2016 IEEE 16th International Conference
    on Data Mining (ICDM), IEEE, 2016, pp. 805–810.'
conference:
  end_date: 2016-12-15
  location: Barcelona, Spain
  name: IEEE 16th International Conference on Data Mining (ICDM)
  start_date: 2016-12-12
date_created: 2018-04-17T11:46:07Z
date_updated: 2022-01-06T06:55:58Z
department:
- _id: '64'
doi: 10.1109/icdm.2016.0094
keyword:
- unsolvability by radicals
- clustering
- fuzzy k-means
- probabilistic method
- approximation algorithms
- randomized algorithms
language:
- iso: eng
page: 805-810
publication: 2016 IEEE 16th International Conference on Data Mining (ICDM)
publication_identifier:
  isbn:
  - '9781509054732'
publication_status: published
publisher: IEEE
status: public
title: A Theoretical Analysis of the Fuzzy K-Means Problem
type: conference
user_id: '25078'
year: '2016'
...
---
_id: '208'
abstract:
- lang: eng
  text: This paper presents a new framework for constructing fully CCA-secure predicate
    encryption schemes from pair encoding schemes. Our construction is the first in
    the context of predicate encryption which uses the technique of well-formedness
    proofs known from public key encryption. The resulting constructions are simpler
    and more efficient compared to the schemes achieved using known generic transformations
    from CPA-secure to CCA-secure schemes. The reduction costs of our framework are
    comparable to the reduction costs of the underlying CPA-secure framework. We achieve
    this last result by applying the dual system encryption methodology in a novel
    way.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Gennadij
  full_name: Liske, Gennadij
  last_name: Liske
citation:
  ama: 'Blömer J, Liske G. Construction of Fully CCA-Secure Predicate Encryptions
    from Pair Encoding Schemes. In: <i>Proceedings of the CT-RSA 2016</i>. LNCS. ;
    2016:431-447. doi:<a href="https://doi.org/10.1007/978-3-319-29485-8_25">10.1007/978-3-319-29485-8_25</a>'
  apa: Blömer, J., &#38; Liske, G. (2016). Construction of Fully CCA-Secure Predicate
    Encryptions from Pair Encoding Schemes. In <i>Proceedings of the CT-RSA 2016</i>
    (pp. 431–447). <a href="https://doi.org/10.1007/978-3-319-29485-8_25">https://doi.org/10.1007/978-3-319-29485-8_25</a>
  bibtex: '@inproceedings{Blömer_Liske_2016, series={LNCS}, title={Construction of
    Fully CCA-Secure Predicate Encryptions from Pair Encoding Schemes}, DOI={<a href="https://doi.org/10.1007/978-3-319-29485-8_25">10.1007/978-3-319-29485-8_25</a>},
    booktitle={Proceedings of the CT-RSA 2016}, author={Blömer, Johannes and Liske,
    Gennadij}, year={2016}, pages={431–447}, collection={LNCS} }'
  chicago: Blömer, Johannes, and Gennadij Liske. “Construction of Fully CCA-Secure
    Predicate Encryptions from Pair Encoding Schemes.” In <i>Proceedings of the CT-RSA
    2016</i>, 431–47. LNCS, 2016. <a href="https://doi.org/10.1007/978-3-319-29485-8_25">https://doi.org/10.1007/978-3-319-29485-8_25</a>.
  ieee: J. Blömer and G. Liske, “Construction of Fully CCA-Secure Predicate Encryptions
    from Pair Encoding Schemes,” in <i>Proceedings of the CT-RSA 2016</i>, 2016, pp.
    431–447.
  mla: Blömer, Johannes, and Gennadij Liske. “Construction of Fully CCA-Secure Predicate
    Encryptions from Pair Encoding Schemes.” <i>Proceedings of the CT-RSA 2016</i>,
    2016, pp. 431–47, doi:<a href="https://doi.org/10.1007/978-3-319-29485-8_25">10.1007/978-3-319-29485-8_25</a>.
  short: 'J. Blömer, G. Liske, in: Proceedings of the CT-RSA 2016, 2016, pp. 431–447.'
date_created: 2017-10-17T12:41:32Z
date_updated: 2022-01-06T06:54:39Z
ddc:
- '040'
department:
- _id: '64'
doi: 10.1007/978-3-319-29485-8_25
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-21T10:43:36Z
  date_updated: 2018-03-21T10:43:36Z
  file_id: '1521'
  file_name: 208-aCCA_P-KEM_final.pdf
  file_size: 462666
  relation: main_file
  success: 1
file_date_updated: 2018-03-21T10:43:36Z
has_accepted_license: '1'
page: 431-447
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
publication: Proceedings of the CT-RSA 2016
series_title: LNCS
status: public
title: Construction of Fully CCA-Secure Predicate Encryptions from Pair Encoding Schemes
type: conference
user_id: '477'
year: '2016'
...
---
_id: '2978'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Kathrin
  full_name: Bujna, Kathrin
  last_name: Bujna
citation:
  ama: 'Blömer J, Bujna K. Adaptive Seeding for Gaussian Mixture Models. In: <i>Advances
    in Knowledge Discovery and Data Mining</i>. Springer International Publishing;
    2016:296-308. doi:<a href="https://doi.org/10.1007/978-3-319-31750-2_24">10.1007/978-3-319-31750-2_24</a>'
  apa: Blömer, J., &#38; Bujna, K. (2016). Adaptive Seeding for Gaussian Mixture Models.
    In <i>Advances in Knowledge Discovery and Data Mining</i> (pp. 296–308). Springer
    International Publishing. <a href="https://doi.org/10.1007/978-3-319-31750-2_24">https://doi.org/10.1007/978-3-319-31750-2_24</a>
  bibtex: '@inbook{Blömer_Bujna_2016, place={Cham}, title={Adaptive Seeding for Gaussian
    Mixture Models}, DOI={<a href="https://doi.org/10.1007/978-3-319-31750-2_24">10.1007/978-3-319-31750-2_24</a>},
    booktitle={Advances in Knowledge Discovery and Data Mining}, publisher={Springer
    International Publishing}, author={Blömer, Johannes and Bujna, Kathrin}, year={2016},
    pages={296–308} }'
  chicago: 'Blömer, Johannes, and Kathrin Bujna. “Adaptive Seeding for Gaussian Mixture
    Models.” In <i>Advances in Knowledge Discovery and Data Mining</i>, 296–308. Cham:
    Springer International Publishing, 2016. <a href="https://doi.org/10.1007/978-3-319-31750-2_24">https://doi.org/10.1007/978-3-319-31750-2_24</a>.'
  ieee: 'J. Blömer and K. Bujna, “Adaptive Seeding for Gaussian Mixture Models,” in
    <i>Advances in Knowledge Discovery and Data Mining</i>, Cham: Springer International
    Publishing, 2016, pp. 296–308.'
  mla: Blömer, Johannes, and Kathrin Bujna. “Adaptive Seeding for Gaussian Mixture
    Models.” <i>Advances in Knowledge Discovery and Data Mining</i>, Springer International
    Publishing, 2016, pp. 296–308, doi:<a href="https://doi.org/10.1007/978-3-319-31750-2_24">10.1007/978-3-319-31750-2_24</a>.
  short: 'J. Blömer, K. Bujna, in: Advances in Knowledge Discovery and Data Mining,
    Springer International Publishing, Cham, 2016, pp. 296–308.'
date_created: 2018-06-05T07:31:39Z
date_updated: 2023-01-10T13:49:50Z
department:
- _id: '64'
doi: 10.1007/978-3-319-31750-2_24
page: 296-308
place: Cham
publication: Advances in Knowledge Discovery and Data Mining
publication_identifier:
  isbn:
  - '9783319317496'
  - '9783319317502'
  issn:
  - 0302-9743
  - 1611-3349
publication_status: published
publisher: Springer International Publishing
status: public
title: Adaptive Seeding for Gaussian Mixture Models
type: book_chapter
user_id: '25078'
year: '2016'
...
---
_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'
...
---
_id: '322'
abstract:
- lang: eng
  text: Reputation systems are used to compute and publish reputation scores for services
    or products. We consider reputation systems where users are allowed to rate products
    that they purchased previously. To obtain trustworthy reputations, they are allowed
    to rate these products only once. As long as users rate products once, they stay
    anonymous. Everybody is able to detect users deviating from the rate-products-only-once
    policy and the anonymity of such dishonest users can be revoked by a system manager.
    In this paper we present formal models for such reputation systems and their security.
    Based on group signatures presented by Boneh, Boyen, and Shacham we design an
    efficient reputation system that meets all our requirements.
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: Christina
  full_name: Kolb, Christina
  id: '43647'
  last_name: Kolb
citation:
  ama: 'Blömer J, Juhnke J, Kolb C. Anonymous and Publicly Linkable Reputation Systems.
    In: <i>Proceedings of the 18th International Conference on Financial Cryptography
    and Data Security (FC)</i>. LNCS. ; 2015:478--488. doi:<a href="https://doi.org/10.1007/978-3-662-47854-7_29">10.1007/978-3-662-47854-7_29</a>'
  apa: Blömer, J., Juhnke, J., &#38; Kolb, C. (2015). Anonymous and Publicly Linkable
    Reputation Systems. In <i>Proceedings of the 18th International Conference on
    Financial Cryptography and Data Security (FC)</i> (pp. 478--488). <a href="https://doi.org/10.1007/978-3-662-47854-7_29">https://doi.org/10.1007/978-3-662-47854-7_29</a>
  bibtex: '@inproceedings{Blömer_Juhnke_Kolb_2015, series={LNCS}, title={Anonymous
    and Publicly Linkable Reputation Systems}, DOI={<a href="https://doi.org/10.1007/978-3-662-47854-7_29">10.1007/978-3-662-47854-7_29</a>},
    booktitle={Proceedings of the 18th International Conference on Financial Cryptography
    and Data Security (FC)}, author={Blömer, Johannes and Juhnke, Jakob and Kolb,
    Christina}, year={2015}, pages={478--488}, collection={LNCS} }'
  chicago: Blömer, Johannes, Jakob Juhnke, and Christina Kolb. “Anonymous and Publicly
    Linkable Reputation Systems.” In <i>Proceedings of the 18th International Conference
    on Financial Cryptography and Data Security (FC)</i>, 478--488. LNCS, 2015. <a
    href="https://doi.org/10.1007/978-3-662-47854-7_29">https://doi.org/10.1007/978-3-662-47854-7_29</a>.
  ieee: J. Blömer, J. Juhnke, and C. Kolb, “Anonymous and Publicly Linkable Reputation
    Systems,” in <i>Proceedings of the 18th International Conference on Financial
    Cryptography and Data Security (FC)</i>, 2015, pp. 478--488.
  mla: Blömer, Johannes, et al. “Anonymous and Publicly Linkable Reputation Systems.”
    <i>Proceedings of the 18th International Conference on Financial Cryptography
    and Data Security (FC)</i>, 2015, pp. 478--488, doi:<a href="https://doi.org/10.1007/978-3-662-47854-7_29">10.1007/978-3-662-47854-7_29</a>.
  short: 'J. Blömer, J. Juhnke, C. Kolb, in: Proceedings of the 18th International
    Conference on Financial Cryptography and Data Security (FC), 2015, pp. 478--488.'
date_created: 2017-10-17T12:41:54Z
date_updated: 2022-01-06T06:59:05Z
ddc:
- '040'
department:
- _id: '64'
doi: 10.1007/978-3-662-47854-7_29
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-20T07:39:54Z
  date_updated: 2018-03-20T07:39:54Z
  file_id: '1431'
  file_name: 322-546_01.pdf
  file_size: 499568
  relation: main_file
  success: 1
file_date_updated: 2018-03-20T07:39:54Z
has_accepted_license: '1'
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2014/546
oa: '1'
page: 478--488
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
publication: Proceedings of the 18th International Conference on Financial Cryptography
  and Data Security (FC)
series_title: LNCS
status: public
title: Anonymous and Publicly Linkable Reputation Systems
type: conference
user_id: '48090'
year: '2015'
...
---
_id: '233'
abstract:
- lang: eng
  text: Motivated by the deterministic single exponential time algorithm of Micciancio
    and Voulgaris for solving the shortest and closest vector problem for the Euclidean
    norm, we study the geometry and complexity of Voronoi cells of lattices with respect
    to arbitrary norms.On the positive side, we show that for strictly convex and
    smooth norms the geometry of Voronoi cells of lattices in any dimension is similar
    to the Euclidean case, i.e., the Voronoi cells are defined by the so-called Voronoi-relevant
    vectors and the facets of a Voronoi cell are in one-to-one correspondence with
    these vectors. On the negative side, we show that combinatorially Voronoi cells
    for arbitrary strictly convex and smooth norms are much more complicated than
    in the Euclidean case.In particular, we construct a family of three-dimensional
    lattices whose number of Voronoi-relevant vectors with respect to the l_3-norm
    is unbounded.Since the algorithm of Micciancio and Voulgaris and its run time
    analysis crucially dependonthefactthatfortheEuclidean normthenumber of Voronoi-relevant
    vectors is single exponential in the lattice dimension, this indicates that the
    techniques of Micciancio and Voulgaris cannot be extended to achieve deterministic
    single exponential time algorithms for lattice problems with respect to arbitrary
    l_p-norms.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Kathlén
  full_name: Kohn, Kathlén
  last_name: Kohn
citation:
  ama: Blömer J, Kohn K. <i>Voronoi Cells of Lattices with Respect to Arbitrary Norms</i>.
    Universität Paderborn; 2015.
  apa: Blömer, J., &#38; Kohn, K. (2015). <i>Voronoi Cells of Lattices with Respect
    to Arbitrary Norms</i>. Universität Paderborn.
  bibtex: '@book{Blömer_Kohn_2015, title={Voronoi Cells of Lattices with Respect to
    Arbitrary Norms}, publisher={Universität Paderborn}, author={Blömer, Johannes
    and Kohn, Kathlén}, year={2015} }'
  chicago: Blömer, Johannes, and Kathlén Kohn. <i>Voronoi Cells of Lattices with Respect
    to Arbitrary Norms</i>. Universität Paderborn, 2015.
  ieee: J. Blömer and K. Kohn, <i>Voronoi Cells of Lattices with Respect to Arbitrary
    Norms</i>. Universität Paderborn, 2015.
  mla: Blömer, Johannes, and Kathlén Kohn. <i>Voronoi Cells of Lattices with Respect
    to Arbitrary Norms</i>. Universität Paderborn, 2015.
  short: J. Blömer, K. Kohn, Voronoi Cells of Lattices with Respect to Arbitrary Norms,
    Universität Paderborn, 2015.
date_created: 2017-10-17T12:41:37Z
date_updated: 2022-01-06T06:55:49Z
ddc:
- '040'
department:
- _id: '64'
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-21T10:30:18Z
  date_updated: 2018-03-21T10:30:18Z
  file_id: '1501'
  file_name: 233-1512.00720v1.pdf
  file_size: 1231102
  relation: main_file
  success: 1
file_date_updated: 2018-03-21T10:30:18Z
has_accepted_license: '1'
main_file_link:
- open_access: '1'
  url: http://arxiv.org/pdf/1512.00720v1.pdf
oa: '1'
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
publisher: Universität Paderborn
status: public
title: Voronoi Cells of Lattices with Respect to Arbitrary Norms
type: report
user_id: '25078'
year: '2015'
...
---
_id: '355'
abstract:
- lang: eng
  text: In the last decade pairings have become an important, and often indispensable,
    ingredient in the construction of identity-based and attribute-based cryptosystems,
    as well as group signatures and credential systems. Consequently, the applicability
    of timing, power, or fault attacks to implementations of pairings is an important
    research topic. We will review some of the known results in this area.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
- first_name: Gennadij
  full_name: Liske, Gennadij
  last_name: Liske
citation:
  ama: 'Blömer J, Günther P, Liske G. Tampering attacks in pairing-based cryptography.
    In: <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>.
    ; 2014:1--7. doi:<a href="https://doi.org/10.1109/FDTC.2014.10">10.1109/FDTC.2014.10</a>'
  apa: Blömer, J., Günther, P., &#38; Liske, G. (2014). Tampering attacks in pairing-based
    cryptography. In <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>
    (pp. 1--7). <a href="https://doi.org/10.1109/FDTC.2014.10">https://doi.org/10.1109/FDTC.2014.10</a>
  bibtex: '@inproceedings{Blömer_Günther_Liske_2014, title={Tampering attacks in pairing-based
    cryptography}, DOI={<a href="https://doi.org/10.1109/FDTC.2014.10">10.1109/FDTC.2014.10</a>},
    booktitle={Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)},
    author={Blömer, Johannes and Günther, Peter and Liske, Gennadij}, year={2014},
    pages={1--7} }'
  chicago: Blömer, Johannes, Peter Günther, and Gennadij Liske. “Tampering Attacks
    in Pairing-Based Cryptography.” In <i>Proceedings of Fault Tolerance and Diagnosis
    in Cryptography(FDTC)</i>, 1--7, 2014. <a href="https://doi.org/10.1109/FDTC.2014.10">https://doi.org/10.1109/FDTC.2014.10</a>.
  ieee: J. Blömer, P. Günther, and G. Liske, “Tampering attacks in pairing-based cryptography,”
    in <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>,
    2014, pp. 1--7.
  mla: Blömer, Johannes, et al. “Tampering Attacks in Pairing-Based Cryptography.”
    <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>, 2014,
    pp. 1--7, doi:<a href="https://doi.org/10.1109/FDTC.2014.10">10.1109/FDTC.2014.10</a>.
  short: 'J. Blömer, P. Günther, G. Liske, in: Proceedings of Fault Tolerance and
    Diagnosis in Cryptography(FDTC), 2014, pp. 1--7.'
date_created: 2017-10-17T12:42:01Z
date_updated: 2022-01-06T06:59:23Z
ddc:
- '040'
department:
- _id: '64'
doi: 10.1109/FDTC.2014.10
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-20T07:22:29Z
  date_updated: 2018-03-20T07:22:29Z
  file_id: '1412'
  file_name: 355-Bloemer2014.pdf
  file_size: 293394
  relation: main_file
  success: 1
file_date_updated: 2018-03-20T07:22:29Z
has_accepted_license: '1'
page: 1--7
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '43'
  name: Securing the Financial Cloud
publication: Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)
status: public
title: Tampering attacks in pairing-based cryptography
type: conference
user_id: '25078'
year: '2014'
...
---
_id: '2976'
author:
- first_name: Marcel Rudolf
  full_name: Ackermann, Marcel Rudolf
  last_name: Ackermann
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Daniel
  full_name: Kuntze, Daniel
  last_name: Kuntze
- first_name: Christian
  full_name: Sohler, Christian
  last_name: Sohler
citation:
  ama: Ackermann MR, Blömer J, Kuntze D, Sohler C. Analysis of Agglomerative Clustering.
    <i>Algorithmica</i>. 2014;69. doi:<a href="https://doi.org/10.1007/s00453-012-9717-4">10.1007/s00453-012-9717-4</a>
  apa: Ackermann, M. R., Blömer, J., Kuntze, D., &#38; Sohler, C. (2014). Analysis
    of Agglomerative Clustering. <i>Algorithmica</i>, <i>69</i>. <a href="https://doi.org/10.1007/s00453-012-9717-4">https://doi.org/10.1007/s00453-012-9717-4</a>
  bibtex: '@article{Ackermann_Blömer_Kuntze_Sohler_2014, title={Analysis of Agglomerative
    Clustering}, volume={69}, DOI={<a href="https://doi.org/10.1007/s00453-012-9717-4">10.1007/s00453-012-9717-4</a>},
    journal={Algorithmica}, publisher={Springer US}, author={Ackermann, Marcel Rudolf
    and Blömer, Johannes and Kuntze, Daniel and Sohler, Christian}, year={2014} }'
  chicago: Ackermann, Marcel Rudolf, Johannes Blömer, Daniel Kuntze, and Christian
    Sohler. “Analysis of Agglomerative Clustering.” <i>Algorithmica</i> 69 (2014).
    <a href="https://doi.org/10.1007/s00453-012-9717-4">https://doi.org/10.1007/s00453-012-9717-4</a>.
  ieee: M. R. Ackermann, J. Blömer, D. Kuntze, and C. Sohler, “Analysis of Agglomerative
    Clustering,” <i>Algorithmica</i>, vol. 69, 2014.
  mla: Ackermann, Marcel Rudolf, et al. “Analysis of Agglomerative Clustering.” <i>Algorithmica</i>,
    vol. 69, Springer US, 2014, doi:<a href="https://doi.org/10.1007/s00453-012-9717-4">10.1007/s00453-012-9717-4</a>.
  short: M.R. Ackermann, J. Blömer, D. Kuntze, C. Sohler, Algorithmica 69 (2014).
date_created: 2018-06-05T07:28:52Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
doi: 10.1007/s00453-012-9717-4
intvolume: '        69'
publication: Algorithmica
publication_identifier:
  eissn:
  - 0178-4617
publication_status: published
publisher: Springer US
status: public
title: Analysis of Agglomerative Clustering
type: journal_article
user_id: '25078'
volume: 69
year: '2014'
...
---
_id: '2977'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Kathrin
  full_name: Bujna, Kathrin
  last_name: Bujna
- first_name: Daniel
  full_name: Kuntze, Daniel
  last_name: Kuntze
citation:
  ama: 'Blömer J, Bujna K, Kuntze D. A Theoretical and Experimental Comparison of
    the EM and SEM Algorithm. In: <i>2014 22nd International Conference on Pattern
    Recognition</i>. IEEE; 2014. doi:<a href="https://doi.org/10.1109/icpr.2014.253">10.1109/icpr.2014.253</a>'
  apa: Blömer, J., Bujna, K., &#38; Kuntze, D. (2014). A Theoretical and Experimental
    Comparison of the EM and SEM Algorithm. In <i>2014 22nd International Conference
    on Pattern Recognition</i>. IEEE. <a href="https://doi.org/10.1109/icpr.2014.253">https://doi.org/10.1109/icpr.2014.253</a>
  bibtex: '@inproceedings{Blömer_Bujna_Kuntze_2014, title={A Theoretical and Experimental
    Comparison of the EM and SEM Algorithm}, DOI={<a href="https://doi.org/10.1109/icpr.2014.253">10.1109/icpr.2014.253</a>},
    booktitle={2014 22nd International Conference on Pattern Recognition}, publisher={IEEE},
    author={Blömer, Johannes and Bujna, Kathrin and Kuntze, Daniel}, year={2014} }'
  chicago: Blömer, Johannes, Kathrin Bujna, and Daniel Kuntze. “A Theoretical and
    Experimental Comparison of the EM and SEM Algorithm.” In <i>2014 22nd International
    Conference on Pattern Recognition</i>. IEEE, 2014. <a href="https://doi.org/10.1109/icpr.2014.253">https://doi.org/10.1109/icpr.2014.253</a>.
  ieee: J. Blömer, K. Bujna, and D. Kuntze, “A Theoretical and Experimental Comparison
    of the EM and SEM Algorithm,” in <i>2014 22nd International Conference on Pattern
    Recognition</i>, 2014.
  mla: Blömer, Johannes, et al. “A Theoretical and Experimental Comparison of the
    EM and SEM Algorithm.” <i>2014 22nd International Conference on Pattern Recognition</i>,
    IEEE, 2014, doi:<a href="https://doi.org/10.1109/icpr.2014.253">10.1109/icpr.2014.253</a>.
  short: 'J. Blömer, K. Bujna, D. Kuntze, in: 2014 22nd International Conference on
    Pattern Recognition, IEEE, 2014.'
date_created: 2018-06-05T07:29:15Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
doi: 10.1109/icpr.2014.253
publication: 2014 22nd International Conference on Pattern Recognition
publication_identifier:
  isbn:
  - '9781479952090'
publication_status: published
publisher: IEEE
status: public
title: A Theoretical and Experimental Comparison of the EM and SEM Algorithm
type: conference
user_id: '25078'
year: '2014'
...
---
_id: '442'
abstract:
- lang: eng
  text: We present a new transformation of chosen-plaintext secure predicate encryption
    schemes with public index into chosen-ciphertext secure schemes. Our construction
    requires only a universal one-way hash function and is selectively secure in the
    standard model. The transformation is not generic but can be applied to various
    existing schemes constructed from bilinear groups. Using common structural properties
    of these schemes we provide an efficient and simple transformation without overhead
    in form of one-time signatures or message authentication codes as required in
    the known generic transformations.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Gennadij
  full_name: Liske, Gennadij
  last_name: Liske
citation:
  ama: Blömer J, Liske G. Constructing CCA-secure predicate encapsulation schemes
    from CPA-secure schemes and universal one-way hash functions. 2014.
  apa: Blömer, J., &#38; Liske, G. (2014). Constructing CCA-secure predicate encapsulation
    schemes from CPA-secure schemes and universal one-way hash functions. Universität
    Paderborn.
  bibtex: '@article{Blömer_Liske_2014, title={Constructing CCA-secure predicate encapsulation
    schemes from CPA-secure schemes and universal one-way hash functions}, publisher={Universität
    Paderborn}, author={Blömer, Johannes and Liske, Gennadij}, year={2014} }'
  chicago: Blömer, Johannes, and Gennadij Liske. “Constructing CCA-Secure Predicate
    Encapsulation Schemes from CPA-Secure Schemes and Universal One-Way Hash Functions.”
    Universität Paderborn, 2014.
  ieee: J. Blömer and G. Liske, “Constructing CCA-secure predicate encapsulation schemes
    from CPA-secure schemes and universal one-way hash functions.” Universität Paderborn,
    2014.
  mla: Blömer, Johannes, and Gennadij Liske. <i>Constructing CCA-Secure Predicate
    Encapsulation Schemes from CPA-Secure Schemes and Universal One-Way Hash Functions</i>.
    Universität Paderborn, 2014.
  short: J. Blömer, G. Liske, (2014).
date_created: 2017-10-17T12:42:18Z
date_updated: 2022-01-06T07:01:03Z
ddc:
- '000'
department:
- _id: '64'
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-16T11:28:34Z
  date_updated: 2018-03-16T11:28:34Z
  file_id: '1351'
  file_name: 442-P-KEM.pdf
  file_size: 377945
  relation: main_file
  success: 1
file_date_updated: 2018-03-16T11:28:34Z
has_accepted_license: '1'
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2014/511.pdf
oa: '1'
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '43'
  name: Securing the Financial Cloud
publisher: Universität Paderborn
status: public
title: Constructing CCA-secure predicate encapsulation schemes from CPA-secure schemes
  and universal one-way hash functions
type: preprint
user_id: '25078'
year: '2014'
...
---
_id: '463'
abstract:
- lang: eng
  text: Several fault attacks against pairing-based cryptography have been described
    theoretically in recent years. Interestingly, none of these have been practically
    evaluated. We accomplished this task and prove that fault attacks against pairing-based
    cryptography are indeed possible and are even practical — thus posing a serious
    threat. Moreover, we successfully conducted a second-order fault attack against
    an open source implementation of the eta pairing on an AVR XMEGA A1. We injected
    the first fault into the computation of the Miller Algorithm and applied the second
    fault to skip the final exponentiation completely. We introduce a low-cost setup
    that allowed us to generate multiple independent faults in one computation. The
    setup implements these faults by clock glitches which induce instruction skips.
    With this setup we conducted the first practical fault attack against a complete
    pairing computation.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Ricardo
  full_name: Gomes da Silva, Ricardo
  last_name: Gomes da Silva
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
- first_name: Juliane
  full_name: Krämer, Juliane
  last_name: Krämer
- first_name: Jean-Pierre
  full_name: Seifert, Jean-Pierre
  last_name: Seifert
citation:
  ama: 'Blömer J, Gomes da Silva R, Günther P, Krämer J, Seifert J-P. A Practical
    Second-Order Fault Attack against a Real-World Pairing Implementation. In: <i>Proceedings
    of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>. ; 2014:123--136. doi:<a
    href="https://doi.org/10.1109/FDTC.2014.22">10.1109/FDTC.2014.22</a>'
  apa: Blömer, J., Gomes da Silva, R., Günther, P., Krämer, J., &#38; Seifert, J.-P.
    (2014). A Practical Second-Order Fault Attack against a Real-World Pairing Implementation.
    In <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i> (pp.
    123--136). <a href="https://doi.org/10.1109/FDTC.2014.22">https://doi.org/10.1109/FDTC.2014.22</a>
  bibtex: '@inproceedings{Blömer_Gomes da Silva_Günther_Krämer_Seifert_2014, title={A
    Practical Second-Order Fault Attack against a Real-World Pairing Implementation},
    DOI={<a href="https://doi.org/10.1109/FDTC.2014.22">10.1109/FDTC.2014.22</a>},
    booktitle={Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)},
    author={Blömer, Johannes and Gomes da Silva, Ricardo and Günther, Peter and Krämer,
    Juliane and Seifert, Jean-Pierre}, year={2014}, pages={123--136} }'
  chicago: Blömer, Johannes, Ricardo Gomes da Silva, Peter Günther, Juliane Krämer,
    and Jean-Pierre Seifert. “A Practical Second-Order Fault Attack against a Real-World
    Pairing Implementation.” In <i>Proceedings of Fault Tolerance and Diagnosis in
    Cryptography(FDTC)</i>, 123--136, 2014. <a href="https://doi.org/10.1109/FDTC.2014.22">https://doi.org/10.1109/FDTC.2014.22</a>.
  ieee: J. Blömer, R. Gomes da Silva, P. Günther, J. Krämer, and J.-P. Seifert, “A
    Practical Second-Order Fault Attack against a Real-World Pairing Implementation,”
    in <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>,
    2014, pp. 123--136.
  mla: Blömer, Johannes, et al. “A Practical Second-Order Fault Attack against a Real-World
    Pairing Implementation.” <i>Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)</i>,
    2014, pp. 123--136, doi:<a href="https://doi.org/10.1109/FDTC.2014.22">10.1109/FDTC.2014.22</a>.
  short: 'J. Blömer, R. Gomes da Silva, P. Günther, J. Krämer, J.-P. Seifert, in:
    Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC), 2014, pp.
    123--136.'
date_created: 2017-10-17T12:42:22Z
date_updated: 2022-01-06T07:01:16Z
ddc:
- '040'
department:
- _id: '64'
doi: 10.1109/FDTC.2014.22
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-16T11:20:54Z
  date_updated: 2018-03-16T11:20:54Z
  file_id: '1336'
  file_name: 463-FDTC14.pdf
  file_size: 437518
  relation: main_file
  success: 1
file_date_updated: 2018-03-16T11:20:54Z
has_accepted_license: '1'
page: 123--136
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '43'
  name: Securing the Financial Cloud
publication: Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)
status: public
title: A Practical Second-Order Fault Attack against a Real-World Pairing Implementation
type: conference
user_id: '25078'
year: '2014'
...
---
_id: '2979'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
- first_name: Gennadij
  full_name: Liske, Gennadij
  last_name: Liske
citation:
  ama: 'Blömer J, Günther P, Liske G. Improved Side Channel Attacks on Pairing Based
    Cryptography. In: <i>Constructive Side-Channel Analysis and Secure Design</i>.
    Berlin, Heidelberg: Springer Berlin Heidelberg; 2013:154-168. doi:<a href="https://doi.org/10.1007/978-3-642-40026-1_10">10.1007/978-3-642-40026-1_10</a>'
  apa: 'Blömer, J., Günther, P., &#38; Liske, G. (2013). Improved Side Channel Attacks
    on Pairing Based Cryptography. In <i>Constructive Side-Channel Analysis and Secure
    Design</i> (pp. 154–168). Berlin, Heidelberg: Springer Berlin Heidelberg. <a href="https://doi.org/10.1007/978-3-642-40026-1_10">https://doi.org/10.1007/978-3-642-40026-1_10</a>'
  bibtex: '@inbook{Blömer_Günther_Liske_2013, place={Berlin, Heidelberg}, title={Improved
    Side Channel Attacks on Pairing Based Cryptography}, DOI={<a href="https://doi.org/10.1007/978-3-642-40026-1_10">10.1007/978-3-642-40026-1_10</a>},
    booktitle={Constructive Side-Channel Analysis and Secure Design}, publisher={Springer
    Berlin Heidelberg}, author={Blömer, Johannes and Günther, Peter and Liske, Gennadij},
    year={2013}, pages={154–168} }'
  chicago: 'Blömer, Johannes, Peter Günther, and Gennadij Liske. “Improved Side Channel
    Attacks on Pairing Based Cryptography.” In <i>Constructive Side-Channel Analysis
    and Secure Design</i>, 154–68. Berlin, Heidelberg: Springer Berlin Heidelberg,
    2013. <a href="https://doi.org/10.1007/978-3-642-40026-1_10">https://doi.org/10.1007/978-3-642-40026-1_10</a>.'
  ieee: 'J. Blömer, P. Günther, and G. Liske, “Improved Side Channel Attacks on Pairing
    Based Cryptography,” in <i>Constructive Side-Channel Analysis and Secure Design</i>,
    Berlin, Heidelberg: Springer Berlin Heidelberg, 2013, pp. 154–168.'
  mla: Blömer, Johannes, et al. “Improved Side Channel Attacks on Pairing Based Cryptography.”
    <i>Constructive Side-Channel Analysis and Secure Design</i>, Springer Berlin Heidelberg,
    2013, pp. 154–68, doi:<a href="https://doi.org/10.1007/978-3-642-40026-1_10">10.1007/978-3-642-40026-1_10</a>.
  short: 'J. Blömer, P. Günther, G. Liske, in: Constructive Side-Channel Analysis
    and Secure Design, Springer Berlin Heidelberg, Berlin, Heidelberg, 2013, pp. 154–168.'
date_created: 2018-06-05T07:33:22Z
date_updated: 2022-01-06T06:58:49Z
department:
- _id: '64'
doi: 10.1007/978-3-642-40026-1_10
page: 154-168
place: Berlin, Heidelberg
publication: Constructive Side-Channel Analysis and Secure Design
publication_identifier:
  isbn:
  - '9783642400254'
  - '9783642400261'
  issn:
  - 0302-9743
  - 1611-3349
publication_status: published
publisher: Springer Berlin Heidelberg
status: public
title: Improved Side Channel Attacks on Pairing Based Cryptography
type: book_chapter
user_id: '25078'
year: '2013'
...
---
_id: '488'
abstract:
- lang: eng
  text: Unattended systems are key ingredients of various critical infrastruc-tures
    like networks of self service terminals or automated teller machines.For cost
    and efficiency reasons they should mostly run autonomously.Unattended systems
    are attractive and lucrative targets for various kindsof attacks, including attacks
    on the integrity of their components and thecommunication between components.
    In this paper, we propose a gen-eral cryptographic framework to protect unattended
    systems. We alsodemonstrate that instantiating the framework with techniques from
    iden-tity based cryptography is particularly well-suited to efficiently secureunattended
    systems.
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Peter
  full_name: Günther, Peter
  last_name: Günther
- first_name: Volker
  full_name: Krummel, Volker
  last_name: Krummel
citation:
  ama: 'Blömer J, Günther P, Krummel V. Securing Critical Unattended Systems with
    Identity Based Cryptography - A Case Study. In: <i>Proceedings of the 5th International
    Conference on Mathematical Aspects of Computer and Information Sciences (MACIS)</i>.
    ; 2013:98-105.'
  apa: Blömer, J., Günther, P., &#38; Krummel, V. (2013). Securing Critical Unattended
    Systems with Identity Based Cryptography - A Case Study. In <i>Proceedings of
    the 5th International Conference on Mathematical Aspects of Computer and Information
    Sciences (MACIS)</i> (pp. 98–105).
  bibtex: '@inproceedings{Blömer_Günther_Krummel_2013, title={Securing Critical Unattended
    Systems with Identity Based Cryptography - A Case Study}, booktitle={Proceedings
    of the 5th International Conference on Mathematical Aspects of Computer and Information
    Sciences (MACIS)}, author={Blömer, Johannes and Günther, Peter and Krummel, Volker},
    year={2013}, pages={98–105} }'
  chicago: Blömer, Johannes, Peter Günther, and Volker Krummel. “Securing Critical
    Unattended Systems with Identity Based Cryptography - A Case Study.” In <i>Proceedings
    of the 5th International Conference on Mathematical Aspects of Computer and Information
    Sciences (MACIS)</i>, 98–105, 2013.
  ieee: J. Blömer, P. Günther, and V. Krummel, “Securing Critical Unattended Systems
    with Identity Based Cryptography - A Case Study,” in <i>Proceedings of the 5th
    International Conference on Mathematical Aspects of Computer and Information Sciences
    (MACIS)</i>, 2013, pp. 98–105.
  mla: Blömer, Johannes, et al. “Securing Critical Unattended Systems with Identity
    Based Cryptography - A Case Study.” <i>Proceedings of the 5th International Conference
    on Mathematical Aspects of Computer and Information Sciences (MACIS)</i>, 2013,
    pp. 98–105.
  short: 'J. Blömer, P. Günther, V. Krummel, in: Proceedings of the 5th International
    Conference on Mathematical Aspects of Computer and Information Sciences (MACIS),
    2013, pp. 98–105.'
date_created: 2017-10-17T12:42:27Z
date_updated: 2022-01-06T07:01:28Z
ddc:
- '040'
department:
- _id: '64'
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-15T13:46:52Z
  date_updated: 2018-03-15T13:46:52Z
  file_id: '1317'
  file_name: 488-MACIS13.pdf
  file_size: 301962
  relation: main_file
  success: 1
file_date_updated: 2018-03-15T13:46:52Z
has_accepted_license: '1'
page: 98-105
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
publication: Proceedings of the 5th International Conference on Mathematical Aspects
  of Computer and Information Sciences (MACIS)
status: public
title: Securing Critical Unattended Systems with Identity Based Cryptography - A Case
  Study
type: conference
user_id: '477'
year: '2013'
...
---
_id: '538'
abstract:
- lang: eng
  text: 'We present a new technique to realize attribute-based encryption (ABE) schemes
    secure in the standard model against chosen-ciphertext attacks (CCA-secure). Our
    approach is to extend certain concrete chosen-plaintext secure (CPA-secure) ABE
    schemes to achieve more efficient constructions than the known generic constructions
    of CCA-secure ABE schemes. We restrict ourselves to the construction of attribute-based
    key encapsulation mechanisms (KEMs) and present two concrete CCA-secure schemes:
    a key-policy attribute-based KEM that is based on Goyal''s key-policy ABE and
    a ciphertext-policy attribute-based KEM that is based on Waters'' ciphertext-policy
    ABE. To achieve our goals, we use an appropriate hash function and need to extend
    the public parameters and the ciphertexts of the underlying CPA-secure encryption
    schemes only by a single group element. Moreover, we use the same hardness assumptions
    as the underlying CPA-secure encryption schemes.'
author:
- first_name: Johannes
  full_name: Blömer, Johannes
  id: '23'
  last_name: Blömer
- first_name: Gennadij
  full_name: Liske, Gennadij
  last_name: Liske
citation:
  ama: Blömer J, Liske G. Direct Chosen-Ciphertext Secure Attribute-Based Key Encapsulations
    without Random Oracles. 2013.
  apa: Blömer, J., &#38; Liske, G. (2013). Direct Chosen-Ciphertext Secure Attribute-Based
    Key Encapsulations without Random Oracles. Universität Paderborn.
  bibtex: '@article{Blömer_Liske_2013, title={Direct Chosen-Ciphertext Secure Attribute-Based
    Key Encapsulations without Random Oracles}, publisher={Universität Paderborn},
    author={Blömer, Johannes and Liske, Gennadij}, year={2013} }'
  chicago: Blömer, Johannes, and Gennadij Liske. “Direct Chosen-Ciphertext Secure
    Attribute-Based Key Encapsulations without Random Oracles.” Universität Paderborn,
    2013.
  ieee: J. Blömer and G. Liske, “Direct Chosen-Ciphertext Secure Attribute-Based Key
    Encapsulations without Random Oracles.” Universität Paderborn, 2013.
  mla: Blömer, Johannes, and Gennadij Liske. <i>Direct Chosen-Ciphertext Secure Attribute-Based
    Key Encapsulations without Random Oracles</i>. Universität Paderborn, 2013.
  short: J. Blömer, G. Liske, (2013).
date_created: 2017-10-17T12:42:37Z
date_updated: 2022-01-06T07:01:51Z
ddc:
- '040'
department:
- _id: '64'
file:
- access_level: closed
  content_type: application/pdf
  creator: florida
  date_created: 2018-03-15T10:35:04Z
  date_updated: 2018-03-15T10:35:04Z
  file_id: '1292'
  file_name: 538-AB-KEM_01.pdf
  file_size: 389797
  relation: main_file
  success: 1
file_date_updated: 2018-03-15T10:35:04Z
has_accepted_license: '1'
main_file_link:
- open_access: '1'
  url: https://eprint.iacr.org/2013/646
oa: '1'
project:
- _id: '1'
  name: SFB 901
- _id: '13'
  name: SFB 901 - Subprojekt C1
- _id: '4'
  name: SFB 901 - Project Area C
- _id: '43'
  name: Securing the Financial Cloud
publisher: Universität Paderborn
status: public
title: Direct Chosen-Ciphertext Secure Attribute-Based Key Encapsulations without
  Random Oracles
type: preprint
user_id: '25078'
year: '2013'
...