7 min readJul 16, 2020


In our first milestone medium post we gave you a minimal inside look what the project is all about. Today, before you read about milestone 2 we let you all know about the project and why Freighter is so an important piece of the puzzle.

The project which SKALY is an part of has been organized by TNO and Health Holland(LSH). The Dutch Life Sciences & Health (LSH) sector is one of nine “top sectors” in the Netherlands. The top sectors are designated by the Dutch Ministry of Economic Affairs and Climate Policy and are selected on their ability to contribute substantially to global societal challenges.

This project has been named Preventive Personal Health Train, in short PPHT. With several consortium partners in this project which en-holds different companies and organizations like; universities, pharmacies, medical record companies, hospitals, GP and SKALY in the form of Dennis Schouten and Peter Willemsen.

SKALY is the innovation partner in this consortium, our goal is to demonstrate that decentralized infrastructure for personal healthcare is possible where the control always stays with the actual owner of the medical history (patient/customer).

Just a short memory lane for everyone, SKALY was invited by TNO to join and demonstrate the power of decentralized healthcare possibilities.

This project will focus on exploring/evaluate how the digital world can support communities and build a decentralized gateway that will reduce the amount of redundancy, and increase the access to health data and thereby accelerate the development of solid health apps and tools. The PPHT will support citizens in a healthy lifestyle. By using the data solution support can be given that will lead to a longer, healthier life.

Within this consortium we are able to demonstrate the power of IOTA, give control back to all citizens. Security and scalability is an very important factor here, as we are preparing to send big amount of data we needed another approach to uphold the demand within an decentralized network.

That is the birth of freighter, protecting consumer health data privacy in an increasingly connected world.

The standardization of data (milestone 2)

Today we are releasing milestone 2 of the PPHT project towards creating a decentralized health data infrastructure. In this milestone we will cover the standardization of data, which are build upon the five pillars set by all project members within the consortium.

  • Privacy
  • Transparent
  • Data (re)usable
  • Open standards
  • Controlled by the individual

This milestone focuses on those pillars within the data standardization. The tooling and open data standards are developed generically (FHIR) in such that they are easily extended to other health areas. Our first proof of concept (PoC) aims at the collection, standardization and governance of health and medical data for Personal Health Vaults (Freighter).

The focus of this PoC will be the feasibility of collection, standardization and implementation of the model for both consumer health data and medical data (figure 1). The data for the standard set will be collected in a Personal Health Vault provided by the TNO project partners in which data is under control of the health consumer. The collected and controlled consumer health data will later be coupled to services that can give personal health advice.

Figure 1

This milestone includes the following updates.

The first update will be a Freighter update, the second update is the FHIR implementation for Freighter to complete the standardization of data. As we researched the open project of, we could not use the solution for the TNO project as it was written for Windows. We like the approach of our community members within very much but windows was not our cup of tea, so we started from scratch.

We would like to point out that in figure 1 SKALY application acts as the data supplier. After some good talks with Jelle from IF we are going to integrate SELV within our PoC for the this project.

This is not yet implemented but it will be demonstrated separately when we finish integrating Freighter FHIR and FRPC within SELV. We are in close collaboration with IOTA Foundation and will showcase to the health industry we (IOTA/SKALY) are the decentralized solution. A special thanks goes out to Jelle and Holger for opening SELV to us.

So without further ado we hereby present.

Freighter private channel (FRPC)

In our previous update, we showed Freighter, the fast decentralized messaging platform on top of IOTA that uses a series of cryptographic measures to download and subscribe to large amounts of data without the need to keep a local state about the channel.

FRPC Introduction video

As was previously mentioned in the first video about Freighter, channels share the same keys among participants, which means everyone was the owner, and you were only protected from those not having access to the channel.

Freighter now has a new extension called Freighter Private Channels (FRPC), where you can create a “channel address” (a public-facing static piece of text, very similar to an IOTA address) where people (or machines) can “dial” to and start a new, private channel with the owner of said address.

It’s very much like a “decentralized email platform”. At Skaly, we began to develop FRPC after the growing need for the use of private channels in our own dashboard. Before FRPC, we used IPFS’s peer-to-peer layer to negotiate a Freighter Channel key between 2 participants, and then move to IOTA from there. Eliminating the need for IPFS allowed us to shrink our app size from 6 to 2MB, heavily reducing CPU usage and code complexity.

Note that there’s nothing wrong with IPFS and what the guys are doing over there is absolutely awesome. In addition, there are many projects that use IOTA and IPFS at the same time, it was just that we only used a very tiny part of IPFS and it gave a big overhead.

If you want to get more technical understanding, we kindly forward you to our Github which has the updated readme with all the specs and tech that is being used.

To see it working instantly in your browser, go to and click “private channels”.

Freighter-FHIR PoC

When using Freighter as the health(vault) platform, and within the TNO project, we made another demo, which allows you to set up a dashboard and take the role of the care provider of tomorrow! All interacting with FHIR/HL7. Please follow this Wikipedia article for more context about FHIR.

This demo allows you to share (and withdraw consent) of (fictional) patient data. The system is built on top of FPC, and is close to what we use in SKALY in a production environment.

The FHIR PoC is unique compared to raw FRPC, because it implements (part of) the FHIR standard, which unifies sharing and storing healthcare data between different systems, showing how IOTA can be part of the adoption of this standard, and on top of that, the PoC introduces an additional layer that allows everyone to withdraw access to data. Not only will it stop people from accessing new data who you previously gave access to, but it also makes sure that any previous data you have sent will be deleted off the Tangle! Sounds impossible, doesn’t it?

It’s actually doable, by using a special kind of digital handshake where a small piece of data, crucial to read the entire channel on the Tangle, will be kept off-tangle.

The trickiest part was to get this piece of data from 1 place to another, without having this piece of data going over the Tangle…

When consent to share and show data is withdrawn, the other party scrubs this piece of data from their drive, and, given that the party is trusted until the point of withdrawal of consent, and that the key on their computer was the only copy of it, then all data is effectively “deleted”.

This in itself shows that not only IOTA is ready for health, it also shows that we can be GDPR compliant yet remain fully decentralized!

If you want to get more technical understanding, we kindly forward you to our Github which has the updated readme with all the specs and tech that is being used.

For a demo of FHIR-Freighter, you can go to for the patient demo and to Note that you need both at the same time so make sure you open them in a separate tab next to each other!

Both the FHIR PoC and FRPC are fully quantum-resistant, this software remains strong even 50 years from now…