Data Unavailability Unconference @Devcon4



Is this a done deal? We’re getting ready to book our tickets and need a final set of dates to plan for.


I can probably make it if it’s before devcon actually starts.


Hello everyone!

We are finalizing things with respect to the venue and based on the schedule will settle for October 28th in the afternoon. Snacks will be provided and perhaps lunch, but the latter remains to be confirmed.

As of now, it seems like we will be around 30 participants, anticipating last minute attendants and registered people not being able to attend. However, currently no one expressed interest in giving a presentation, so I will try to use coercion (joke) :

  • @gluk64 @barryWhiteHat @yondonfu Want to talk about rollup/rollback? One could present the rollup/rollback construction (requiring data availability and how to address that) and another could present the on-chain data availability approach and how to optimize this? I think this could be 2 separate presentations, as there is a lot of content.

  • @yondonfu You mentioned a form of data exchange where data needs to become available once a payment is completed. Could you present something on this?

  • @liam @nginnever It seems like you guys are the only ones that have something related to payment/state channels (plasma chains are not state channel crew member here). Would you want to present the problem and current solutions being thought of?

  • @philosopher Would be great to have you present Plasma EVM and your current solution for data availability problem. Perhaps someone from Skale would like to do the same? @kladkogex

  • @paulhauner or someone else that works on Ethereum 2.0 should give a presentation on current solution being adopted for shards (maybe @djrtwo ? I’m pushing it, sorry Danny)

  • @sourabhniyogi @mkchung Would be nice to see how you are using erasure coding for plasma. Want to give a short presentation?

  • @gakonst @kfichter You guys could probably do another presentation on Plasma? I know you both thought a lot about the various constructions and the data related requirements.

  • I’m sure someone from Gnosis has something interesting to share when it comes to data availability :slight_smile: @josojo @StefanGeorge

Anyone else that I didn’t mention, but is interested in presenting, please comment below :). I think having 8-10 short presentations is enough for an afternoon and we will aim for that.

Reminder: Presentations should …

  • Last around 10 minutes
  • Present the system used
  • Explain why data availability is a problem in this context
  • Explain the solution being used for now (if any)

Focus is on the discussion, so make sure you gear the presentation to encourage participation: mention open problems, potential flaws, trade-offs chosen, etc. We are there to discuss, learn and improve our current means of tackling data availability related problem.


@musalbas @asonnino it would be great if one of you could come and discuss your approach in . Someone else could present and summarize the paper if none of the authors can make it.


I will only be in Prague from the 29th unfortunately


I’m not sure if data availability is directly a state-channels problem, Liam would probably have better insight than myself on the general theory there. I’m exploring verification game additions to state-channels in a form I call Forward-Timelocked Transactions which is similar to Plasma Debit where we see state-channels merging with plasma. Assignability of channels becomes perhaps useful.

Would be happy to present something on all of this.


Interested in attending!

Also, it ain’t, I would argue that it’s the exact same problem across the board for all layer two solutions.


Hi! I might be able to make the last couple of hours.

Is there a venue yet?


I would like to know more about the topic…if there is still space available.
The topic will also occupy us in our project.


@PhABC: Unfortunately, @sourabhniyogi and I won’t be able to make it on Oct 28th. We are arriving in Prague Oct 29th Midnight.


I (Jan Gorzny) am interested in attending - I am (and we at Quantstamp are) interested in researching the security and formal verification of many of these topics (and plasma and state channels in particular).


No problem. And 5~6 people going to be there with me.


Hey, thanks for organising but I cant make the 28th. You can take me off the list.


That’s unfortunate! Perhaps see you elsewhere :).

Cool! So long as there is a data availability component that would be interesting. I think it would be useful to have various examples with various assumptions about data availability.

Adding you to the list :).

Awesome! Yes, it’s almost 98% confirmed to be at this hotel, 2 mins away from the congress center.

Since we are close to capacity, please wait until the final count is in see if there is extra room. Thanks!

I’m sad to hear this. Hard to accommodate everyone unfortunately.

Added you!

Excellent. Also, since space is limited and we want to maximize benefits to the ecosystem, would it be possible to only bring 2-3 people from your team total? With only 30 places there isn’t room for many people. It’s possible we will have more room, but unclear at this point, so we prefer being conservative with the number of attendees.

Unfortunate to hear and thanks for letting us know.


I’ve been exploring solutions to the fair exchange problem where party A wants to atomically swap payment with party B for a verifiable digital good (i.e. some data that might’ve also transformed by some costly computation) - past research/literature includes zero-knowledge contingent payments and this post Fair exchange without a trusted third party. I can talk about some of the general ideas here, how this problem manifests specifically in the context of paying for something like video processing and what some promising directions for further exploration might be. This topic is a slightly different flavor of the data availability problem that is commonly discussed in the context of layer 2 scalability solutions, but it still exhibits some of the same types of headaches like speaker/listener fault equivalence so perhaps people would be up for discussing and maybe there is some overlap with the research on verification games that @nginnever is doing as well.


As @fraetz won’t make it, @pmizel can change places with him. Hope that’s fine.

Best regards,


Do we have an exact time for the gathering?


Not sure if I’ll be able to make it, don’t want to take up a space from someone. Sorry for the last minute notice.


@gluk64 We have the place from 1pm to 6pm, so what about starting around 13h30?