Online Seminar
GAPS
About

Online GAPS continues the GAPS 2025 workshop, as a regular online seminar. It provides a platform for researchers interested in provable security for symmetric-key cryptography. Topics include proof techniques, security notions, and generic attacks; related topics such as cryptanalysis and mathematical foundations are also welcome.

Schedule
Upcoming talk
Understanding the Duplex and Its Security
Bart Mennink (Maastricht University)
Wednesday, July 15, 2026 at 08:00 UTC

At SAC 2011, Bertoni et al. introduced the keyed duplex construction as a tool to build permutation based authenticated encryption schemes. The construction was generalized to full-state absorption by Mennink et al. (ASIACRYPT 2015). Daemen et al. (ASIACRYPT 2017) generalized it further to cover much more use cases, and proved security of this general construction, and Dobraunig and Mennink (ASIACRYPT 2019) derived a leakage resilience security bound for this construction. Due to its generality, the full-state keyed duplex construction that we know today has plethora applications, but the flip side of the coin is that the general construction is hard to grasp and the corresponding security bounds are very complex. Consequently, the state-of-the-art results on the full-state keyed duplex construction are not used to the fullest. In this work, we revisit the history of the duplex construction, give a comprehensive discussion of its possibilities and limitations, and demonstrate how the two security bounds (of Daemen et al. and Dobraunig and Mennink) can be interpreted in particular applications of the duplex.

Calendar of Talks

Please note that all times are given in UTC. You may consider adding the calendar (or a specific event) to your Google account; in that case, the times in your calendar will be adjusted to your time zone setting.

Instructions

The seminars take place on Zoom, and recordings of the presentations may be uploaded to YouTube.

For audience
Joining live session:
  1. If you wish to join the live session, please request access using the following form. You may also consider joining the google group. In either case, please indicate your name and affiliation when requesting access.
  2. The Zoom meeting link and instructions will be posted on the google group / sent to emails by request few hours before the session.
  3. Please join at least 5 minutes ahead of the scheduled start.
  4. Please mute your microphone during the talk, unless you want to ask a question.
  5. We strongly encourage questions. You may unmute and directly ask the question, or write on the in-built chat and the moderator will inform the speaker.
  6. All talks and up to 15 minutes of Q&A will be recorded. An unrecorded Q&A may follow directly after that.
Watching the recorded talks:
  1. We will post all talks to the YouTube channel, if the speaker agrees.
  2. A google group conversation thread might also be available (for up to 15 days) for offline discussions with the speaker, if they consent.
For speakers
  • One of the goals of this online seminar is to make research on symmetric-key cryptography more widely accessible, so by default we will share the talk recordings on YouTube. Please let us know in advance if you DO NOT want your presentation to be recorded. If your presentation is recorded, please ensure that it does not include any copyrighted material.
  • Talks are expected to last approximately 1h. The format is flexible, but talks should be accessible to a broad audience.
  • Try to join about 10-15 minutes before your session to make sure your setup is working smoothly.
Contact
The online GAPS seminar is organised by:

  • Ritam Bhaumik
  • Wonseok Choi
  • Avijit Dutta
  • Ashwin Jha
  • Mustafa Khairallah
  • Charlotte Lefevre
  • Yaobin Shen

You may contact them at onlinegaps@gmail.com to suggest talks, or to join the google group. Please note that talk slots are limited, so we may not be able to accommodate every suggestion.