Purpose: Meeting of experts to discuss technical details of sending encrypted emails using OpenPGP.

This is an event open for anybody involved in the development of email clients using OpenPGP for encryption.

The meeting will take place on October 20/21, 2018 in Brussels (Belgium).

NOTE: This is a meeting of those who develop software related to OpenPGP email. Thus, we will have a lot of tech talk about key servers, key discovery, subject encryption, password recovery, security/policies, etc. If you just are interested in these topics as a user, you probably will be bored to death ;-) .

Thus, you’re very welcome to join us if you are working in the area of

  • technical details
  • for sending encrypted emails
  • with OpenPGP
  • in a project or product

Note however, that due to capacity reasons we don’t want to have more than 1-2 people from each project/product. As space is limited, we can accept only around 30 attendees at our host Mailfence in Brussels.

Rules: This is a public meeting. As we want to be fully transparent, anything discussed during the meeting is considered public.

If you want to attend, please send an informal email to Patrick Brunschwig: mailto:patrick@enigmail.net (ideally with some description of your role in this area).

If you need funding for your travel/hotel expenses please also get in contact with Patrick.


The event will take place at the offices of Mailfence/Emakina common offices, at Rue Middelbourg 64 A, 1170 Brussels.


  • Public Transport: take tram nr. 94 or bus nr. 95 to Wiener
  • Car: there are parking spaces in the courtyard in front of the offices.


The event location is in the south of Brussels, in an area without many hotels. There are a number of BnB’s in the area; otherwise I recommend a hotel around De Brouckère/Gare Centrale (downtown) or Schuman (European Quarter), from where you can take the metro to Hermann Debroux, and then tram nr. 94 to Wiener.


Friday, October 19, 2018:

  • from 19:30: Informal gathering at at the Winery (Trois Tilleuls Street 1, 1170 – Brussels, https://www.winery.be ).

Saturday, October 20, 2018:

  • 09:30: Welcome, Organizational Issues, Agenda and Schedule
  • 10:00: Introducing each other
  • 10:30: Plenary Talks
  • 12:30: Lunch
  • 13:30: Organizing Working Groups
  • 14:00: Working Groups
  • 19:00: Key Signing Party
  • 20:00: Dinner

Sunday, October 21, 2018:

  • 9:30: Working Groups
  • 12:30: Lunch
  • 13:00: Working Group
  • 15:00: Final Working Group Reports
  • 15:45: Wrap up
  • 16:30: End


So far, we participants from the following project/tools/organizations have signed up:

  • BSI
  • Delta Chat
  • Enigmail
  • Fluidkeys / Expirybot
  • GnuPG
  • Gpg4o
  • Gpg4win
  • K-9
  • Kmail
  • Mailfence
  • Mailpile
  • Mailvelope
  • Mutt
  • NextLeap
  • NotMuch
  • OpenKeychain
  • OpenPGP in OCaml
  • OpenPGP.js
  • Protonmail
  • R2Mail2
  • Schleuder
  • Sequoia PGP
  • SKS Keyserver
  • Uni Leuven

Plenary Sessions

Working Groups

Day 1

  • new standard for OpenPGP: TLS 1.3, RFC4880bis - Phil Zimmermann
  • SKS keyserver - Kristian Fiskerstrand
  • Autocrypt level 2
  • MUA state sync
  • Counter MITM
  • Webmail / Autocrypt
  • Multiple Key Discovery methods
  • Signature taking over time
  • protected headers

Day 2

  • keys.openpgp.org + GDPR concerns
  • unspoofable security indicators
  • Deletable Email


The notes for all sessions can be found here: Meeting Minutes.