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# System prepended metadata

title: Meeting Minutes
tags: [Meetup]

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Meeting Minutes
===


:::spoiler Document Usage
This document is used for all minutes of the WoT CG. 
After the meeting, the contents will be copied to the GitHub with a PR.

===

###### tags: `Meetup`

:::spoiler Document Usage
This document is used for all minutes of the WoT CG. 
After the meeting, the contents will be copied to GitHub with a PR.
For one week, changes can be requested and then the PR will be merged.
After the PR is merged, the content here can be deleted.

Document Access:
- Everyone has read and commenting access
- Cristiano Aguzzi and Ege Korkan can edit the document
- Other people can request write access for a meeting
- The scribe of the meeting will have write access

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:::info

:date: **Date:** 15 December 2025

### :bust_in_silhouette: Participants

<!-- This list will copied over from the meeting tool -->
- Ege Korkan
- Cristiano Aguzzi
- 


:writing_hand: **Scribe:** Ege

----


### Welcome

Ege: Welcome Everyone! we are at Meetup 32! All slide are public
Ege: you can find us in different places on the web

### News

Ege: 


### Meetup Presentation

Ivan: I will share some of our research results. The intersection point between WoT and Blockchain. To enable zero-trust oracles.

Ivan: In IoT Prism Lab, we work on different verticals.

Ivan: This work is of course possible thanks to collaboration with my colleagues Federico and Lorenzo.

Ivan: We want to enable a decentralized IoT Global Market. We did not arrive there with the IoT we have today.

Ivan: There are some challenges ahead of this. Centralization and lack of transparency is what we see first but actually getting data is not enough since we cannot trust it. We can trust bigger amounts of data though.

Ivan: Interoperability is solved with WoT so let's see the other ones.

Ivan: We see a trend where the users want the data of something like the temperature in a location but doesn't matter who provides it, as long as they can trust it.

Ivan: How can be we decouple the data request and the provider.

Ivan: Why WoT? We are familiar, it is standardized interface for things and directories, it has semantic description

Ivan: When it comes to blockchain, we can say that it is a ledger where the nodes are linked to each other. So it is like a distributed database but without an admin.

Ivan: Smart Contracts are leveraging blockchain's properties. So they are immutabile, transparent, secure, permissionless.

Ivan: However, smart contracts can only work on the data that exists in the blockchain network.

Ivan: Oracles come into play here. They are able to access the outside data.

Ivan: Here are some use cases. A farmer can get money if there is less than a threshold of rain.

Ivan: Without IoT, it is just one's word against the other. If we use some sensors, that data cannot be trusted since they are easy to tamper.

Ivan: We can put smart contracts in there. The oracle can read data from multiple sensors and the payout would be automated. Every step is also auditable.

Ivan: Now with an oracle, you are having a single point of failure or trust. This is called the oracle problem. We propose using multiple oracles, like using multiple sources of data.

Ivan: This is a hot topic in the academia. but it is always centralized approaches.

Ivan: So we propose Zonia. (lists the properties of Zonia and shows the architecture diagram)

Ivan: We see that we can pay the data producers, we can manage metadata via directories as well.

Ivan: Now that we see the different actors, let's get into how it works. Let's start with the example of CO2 level in NYC.

Ivan: We select a subset of oracle based on reputation and randomness.

Ivan: They can get TDs from TDD, go to the devices.

Ivan: Once one read flow is done, we can update the reputation of the oracles.

Ivan: So how do we use WoT? We use TDD and we have used Zion, an open-source TDD.

Ivan: (explains how an indexer is rewarded)

Ivan: So here is our real-life scenario. We have weather stations etc. on the field.

Ivan: So the contract is paying out if the temperature is more than 50C for 5 consecutive queries.

Ivan: Also, we do an evluation where anyone can enter the network with virtual sources.

Ivan: The results show that the attacks are not succesful if we have more and more of zonia

Ivan: We also see a strong correlation with reputation decreasing and faking the data.

Ivan: We also see the performance evaluation

Ivan: Also we have some impressive results for the cost.

Ivan: We have some future work

Ivan: 

Ivan: 

## Q&A


Ege: what is the minimum nb of oracles and data sources? 

Ivan: it is a difficult question for distributed systems in general. You also need different owners of oracles and nodes.

Ege: What if the sensor nodes write to the network? More delay but should be ok?

Ivan: We have a fast resolution in seconds. It is not economically sustainable. No body is paying for the data. If the requested data is delivered, we can charge the requester. 

Ivan: That is also one the reason that people say that IoT and blockchain cannot be done.

Ege: What if the initial contract is made on the premise of long term data recording?

Ivan: Maybe yes but we want ZONIA to be a generic platform. That way, it would be rather specific.

Ege: how does the oracle know which Thing to use? Via JSON Path? You say data type. what do you mean?

Ivan: You use JSON Path of the TDD spec. For geolocation, it is all sensors in that area.

Ege: Would it not mean that you hard code the query strings?

Ivan: You can actually adapt your TD to match the queries as they are open source. It is an incentive.

Ege: Pain points or feature requests about the WoT standards?

Ivan: We used standard out of the box. Geolocation queries would be nice. We have used postgis extension of postgres database.

Cris: You can also use live location. We have experimented with it by using a property for it.

Cris: It would be also nice to have tags defined for specific properties, like tagging for temperature or atmospheric. 

Cris: We also need to be able to get a part of a TD, not the whole TD.

Ege: Ok I see. Like a property scoped and maybe a link to the full TD.

Ege: Also it seems your needs are more on the Discovery spec.

## :ballot_box_with_check: Resolutions



## :exclamation: Action Items


## :envelope_with_arrow: Feedbacks



## Presentation Summary


- 