eHealth 2018 http://www.ehealth20xx.at/program-blockchain/

A BLOCKCHAIN-POWERED INTEROPERABILITY
FRAMEWORK FOR HEALTHCARE
https://www.grapevineworld.com
https://www.grapevineworldtoken.io
Massimiliano Masi
eHealth 2018, Vienna, May 9, 2018

The case for interoperability in eHealth
The blockchainS
Pitfalls for healthcare blockchain
The Grapevine project
Massimiliano Masi: Intro to Blockchain ©Grapevine World GmbH 2/30

The definition of Interoperability as an aspect of Security
ISO 27000 is the standard governing security aspects of IT systems
Healthcare Data Sharing is subject to the ISO dictates
Defines the CIA Triad: Confidentiality, Integrity, Availability
If data is not accessible because of lack of interoperability, it is not available
But interoperability is not achieved by adopting a standard: there are so many to choose
from!
Massimiliano Masi: Intro to blockchain ©Grapevine World GmbH 7/30

Highly technological (disconnected) islands
DICOM, for the communication of medical imaging information (1980)
Health Level 7, definition of EMR, administrative parts
ISO, communications
OASIS, for message content
What happens if one or more standard change version and breaks backward
compatibility?
Need governance and enterprise architectural approach

Integrating the Healthcare Enterprise
Born in 2001 to foster the coordinated adoption of standards

Integrating the Healthcare Enterprise
Enterprise Architectural Approach (similar to TOGAF, Zachman)
Integration Profiles, Actors, Transactions, to fulfil a specific clinical use case
Architecture emerges from the grouping of profiles
Example: IHE XDS

The Profile Grouping
At the core of the IHE methodology we have the profile grouping (can be formalized in
algebra)
Merges the functionalities of several profiles to achieve complex clinical use cases
Used in other domains
In Energy (the IES German/Austrian project with mappings to the SGAM)
In eGovernment (the e-SENS LSP, European Interoperability Framework)

The first concept of Blockchain was introduced by Haber et al. 3, the digital safety deposit box
Schneier et al. 4
introduced the concept of Secure Logs (avoiding attackers to gain knowledge
by accessing logs)
Vishnamurty et al. 5
where a token was used to keep p2p file trading in check, ensuring
consumers be able to make micro payments to suppliers for their services.
Szabo 6, is also a reference on the topic Bitcoin's technology completed the puzzle!
____________________
3 S. Haber, and W.S. Stornetta, How to timestamp a digital document
4 B. Schneier, J. Kelsey, Cryptographic support for Secure Logs on Untrusted Machines, in Proceedings of the 7th USENIX
5 V. Vishnamurty et al., Karma: A secure economic framework for peer-to-peer resource sharing, 2003
6 N. Szabo, Formalizing and securing relationships on public networks, 1997

In 2008, Satoshi Nakamoto 7 made public the Bitcoin Paper.
It aimed at defining a decentralized model avoiding a central timestamping authority, and a
distributed ledger where transactions from/to addresses are stored.
He proposed a solution to achieve consensus in hostile environments by adopting the Proof-
of-Work, initially from Dwork et al. 8 and from hashcash.org
____________________
7 Conspiration theory: SAmsung, TOSHIba, NAKAmichi, MOTOrola ,
8 C. Dwork, and M. Naor, Pricing via Processing or Combatting Junk Mail, Crypto 92

In the Blockchain, since we transfer value, everyone is encouraged to cheat! 
Several consensus model
Consensus in trusted environments
Consensus in hostile environments (byzantine)
Clearly, if the consensus style changes, also the deployment of the Blockchain changes.
Permissioned (Hyperledger Sawtooth, Coco framework)
Public (Bitcoin, Ethereum, EOS, Rai)

Achieving consensus is complex.
The CAP theorem
It is impossible for a distributed system to simultaneously provide Consistency, Availability, and
Partition Tolerance. A distributed system can satisfy any two of these, but not all three.
The Proof-of-Work achieves consensus in hostile environments by solving the following equation
𝐹𝑑 𝑐, 𝑥 → 𝑆𝐻𝐴256 𝑆𝐻𝐴256 𝑐 𝑥 <
2224
𝑑
where d is increasing constantly. Miners pool use specialized hardware (ASICs) to perform the PoW.

Block definition
A block is a data structure used to communicate incremental changes to the local state of a node. A
block consists of a list of transactions, a reference to a previous block and a nonce. A block lists
some transactions the block creator (the "miner") has accepted to its memory-pool since the
previous block. A node finds and broadcasts a block when it finds a valid nonce for its PoW
When a miner "closes" the block it has a reward (12,5 bitcoins now).
Blockchain
The longest path from the genesis block, i.e., the root of the tree, to a leaf is called the Blockchain. The
Blockchain acts as a consistent transaction history on which all nodes eventually agree.
____________________
10 R. Wattenhofer, The Science of the Blockchain

The Blockchain data structure is an ordered, back-linked list of blocks of transactions 9.
____________________
9 A. Antonoupoulus, Mastering Bitcoin, O'Reilly

In 2013, Vitalik Buterin proposed Ethereum, a Blockchain who is to solve some bitcoin's curses
The ASICs: since mining new blocks comes with a reward, the PoW secures condence that the
blockchain will remain canonical, and ensures the wealth of the mechanism. However it should
be open to as many people as possible, and it should not be possible to make a linear profit out of
it, especially not with a high initial barrier.
The scripting: The "smart contract" (a contract in a electronic form) has been introduced in the
50s. Since the Blockchain can be a distributed notary service, adding such functionality would be
a benefit.

Ethereum has a different execution model.
It provides a quasi-Turing language in the EVM, Ethereum Virtual Machine.
Languages can be built on top of the EVM, such as Solidity, Serpent, and LLL.
In order to avoid to consume miner's resources, and to avoid DDoS, each execution of
of a EVM instruction costs gas
https://ethgasstation.info.

What is blockchain good for?
Not for storing healthcare data: it’s inefficient, and data is publicly available (even if
is encrypted!)
Not for storing pointers to data: there is no advantage
• The benefit of transparency is reduced
• The benefit of data ownership is reduced
• Need p2p integration with the off-chain parties
• Introduce more attack vectors

The CRAB paradigm
Blockchain is immutable: the Create-Read-Update-Delete (CRUD) does not apply
CRAB: Create-Read-Append-Burn. Append transactions, burn encryption keys.
Data is anyway publicly available in encrypted form, confidential as long as the
as the algorithm is secure
Does not seem to apply to the GDPR’s right to erasure of data.
____________________
A.V. Humbeek, The Blockchain GDPR Paradox

Grapevine project
Shows two use of blockchain applied to an healthcare study
Patient monetization of clinical data
Formal achievement of provenance of clinical data

Data Provenance
Provenance is the foundation of data quality,
Usually implemented by automatically capturing the trace of data manipulation
over space and time.
In healthcare, provenance becomes critical since it encompasses both clinical
research and patient safety.

Use Case
John is feeling tired, goes to see his General Practitioner, Anna;
Anna decides to further investigate for cardio-related diseases sending John to
have two subsequent laboratory analysis, performed by Lab1 and Lab2;
Anne decides to have a consultation with a specialist, Bob, a Cardiologist
working in the Central Hospital and prepares a patient summary for John
(containing the lab results);
Bob have doubts regarding the results and could not verify its
provenance

We aim at approaching the data provenance by
• Normalizing the health data in a canonical form, inspired by real projects
using DS4P (IHE, HL7)
• For each item, expressing "chained" provenance records in W3C PROV
(international standard defining a data model for data provenance)
• Distributing the records chain using a smart contract on Hyperledger (a
blockchain implementation)
• Querying data and provenance from mobile, and from portals (IHE / FHIR)
Standards-based
Our solution is entirely based on open standards from W3C (PROV, DSG), IHE
(Sequoia, NwHIN), and HL7 (CDA, FHIR)

Blockchain as emergent technology
• Lot of enthusiasm and scepticism around
• Is its full potential really expressed?
• Beware of the adHoc implementations: immutability is forever, and forever is
a long time
• History of attacks to IT Security, not to cryptography: the IT architecture is
sovereign

Input from Attendees / Discussion

eHealth 2018 http://www.ehealth20xx.at/program-blockchain/

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à eHealth 2018 http://www.ehealth20xx.at/program-blockchain/

Similaire à eHealth 2018 http://www.ehealth20xx.at/program-blockchain/ (20)

Plus de Massimiliano Masi

Plus de Massimiliano Masi (17)

Dernier

Dernier (20)

eHealth 2018 http://www.ehealth20xx.at/program-blockchain/