Is decentralized identity the future of aviation?

Over a decade ago, a group of entrepreneurs explained how passports would be replaced by blockchain-enabled digital IDs. I remember being enthusiastic about the project but skeptical about the speed of progress. Imagine breezing through check-ins with a blockchain-based ID system – a dream come true, right?

Not long ago, we read reports about a crypto hacker Christopher Ellis who was developing a “world citizenship passport” on the blockchain. A decade later, Ellis is still at it – regularly updating the project – with significant technical progress and virtually no adoption.

Although Ellis’ project hasn’t made much headway, the entire decentralized identity space has made some progress.

The aviation industry has been strung along with the promise of safe, decentralized blockchain-based digital identity. With billions of dollars of venture capital and large-scale trials, we’ve moved in the direction of realising this promise. 

Ground reality

As anyone who has flown in the last decade can attest that centralized digital identity has become ubiquitous in the travel industry.

Most US States now allow domestic travel using mobile IDs; a similar project in the EU will be fully-operational by the end of 2026; and the International Air Transport Association is rolling out a global digital ID standard for air travel. 

As impressive as all of these milestones are, none of these projects are decentralized or use blockchain. 

Despite this, the technology behind decentralized identity has come a long way. Decentralized identity has made headways in other fields such as supply chain and medicine. According to a  venture capital consortium,  it was found that there were over 400 government-backed decentralized identity initiatives, but  less than 10% is targeted for air travel.

There have been some major trials which have attempted to use decentralized identity for air travel, but none have yet been deployed on a large scale. SITA partnered with Indicio, one of the largest decentralized identity providers in the world And are now working on creating a technology standard for decentralized identity for passenger air travel. 

The US Department of Homeland Security has also been trialing decentralized identity since 2021, but its implementation for domestic travel within the United States has been a challenge. Governments and airlines have carried out dozens of small scale trials using everything  from insurance to air miles, but none have been deployed at scale. 

Overcoming obstacles 

Timothy Ruff, a grandmaster on the subject, attributed the problem of adopting decentralized identity to three main reasons – 

1. Passenger decentralized identity schemes are built as platforms rather than protocols.

2. These projects lack the ability to quickly recover from attacks.

3. Passenger digital identity suffers from privacy issues.

Ruff has been there from the very beginning. In 2013, he founded Evernym, one of the earliest decentralized identity providers. He was one of the founders of Hyperledger – which is the basis for nearly all decentralized technology which currently exists.

Decentralized identity has a number of advantages that make it more desirable (on paper) than centralized identity. Blockchains and other decentralized identity projects are not “owned” by anyone – their control can be cryptographically shared between key stakeholders such as government agencies, law enforcement, airlines, airports, and international bodies. There is complete transparency – blockchains can be audited by anyone using block explorers. Lastly, they allow everyone to build their own private apps on a shared network that guarantees interoperability.

The reality is that most decentralized projects are implemented in a way that destroys the advantages of decentralization.

Blockchains become de facto platforms

If not everyone can agree to use a single blockchain, then there is no interoperability. Fragmented projects with many small blockchains means few players in each blockchain, with the end result being that small blockchains are not truly decentralized.

Blockchains are much more expensive and difficult to maintain than centralized platforms. If blockchains behave like platforms, why not just use platforms?

The air travel industry’s current solution of just creating large government-backed platforms is more efficient than using blockchains that have all of the same drawbacks as platforms.

The long term solution is to develop protocols instead of platforms. If a platform is the electrical grid itself, then a protocol is the agreement on the type of electrical socket. Protocols can be “attached” to existing platforms and blockchains, making them interoperable. Blockchains are a necessity  but not a sufficient component in the creation of a global decentralized passenger ID system.

Building resilience

Decentralized projects are more resilient against attacks when compared to non-decentralized projects. Because decentralized projects are built on a set of rigid rules that are hard to change unless the entire community agrees to change the rules.

The very same rigid rules that make decentralized communities hard to attack also makes it harder for them to recover from attacks. Ruff explained that no decentralized projects have figured out “key rotation” – the process of changing cryptographic keys to prevent or recover from an attack.

In decentralized ID projects, passenger identifiers are tied to cryptographic keys. Changing keys while ensuring that the identifier remains stable is very difficult, especially if external parties such as airlines rely on the keys for trust. The lack of a centralized authority makes it difficult to uniformly enforce key updates across the entire network. This creates many complicated trade-offs between security and usability.

Tackling privacy issues 

One of the main advantages of decentralized identity is that it gives users more privacy and anonymity.

Decentralized identity is significantly more complicated and expensive, but in many areas this is offset by its privacy advantages. In the context of industries such as the supply chain or social media, this is almost always worth the cost.

When flying, passengers have no expectation of anonymity. The issue is legal, rather than technical. In the post 9/11 world, there is a global consensus that security checkpoints are needed to protect passengers. 

Airports are antithetical to privacy, airlines, customs, and police all track passengers. There are  cameras  everywhere,  with dedicated teams to monitor passengers. 

This means that the aviation industry needs to find other benefits from decentralized identity that have nothing to do with anonymity.

In ten years… 

While decentralized identity hasn’t yet seen large-scale adoption in aviation, it has found its place in industries such as finance, supply chain, and healthcare.

The problems of platforms versus protocols, key rotation, and privacy are not unique to aviation. Projects such as the KERI protocol are solving these issues in other industries. KERI isn’t the only project which is consciously attempting to solve these issues, a new crop of contenders is currently working towards the same goal. 

As decentralized identity becomes more widespread in other industries, it will slowly (and invisibly) infiltrate passenger aviation. 

Some enthusiasts at a Bitcoin conference predicted that by now, everyone would be using decentralized identity for travel. Ten years later, I’ve become one of them, telling people that decentralized identity is the future of the next decade.