I went to the DMV last week and the visit unfolded as you'd expect: A lot of filling out paper forms and waiting on wooden benches. The place is a technology time warp and perhaps that's not a big deal--after all, you only have to go there every 5 years if you want to drive a car.

The trouble is we use our drivers license for many other things, from boarding a plane to entering a bar. Our license is a powerful document that tells the world who we are. And yet, the gatekeeper to this identity system is a goofy motor vehicle agency that has a fetish for clipboards.

That’s why the idea of blockchain for identity is so intriguing. In theory, it will soon be possible to store our personal data on the blockchain, using biometrics to grant access only to those who ask for permission to see it. This could mean a day will come when we no longer need to rely on credit agencies like Equifax to collect and store troves of our personal information. More ambitious visions of identity--backed by the likes of Accenture and Microsoft--envision using blockchain as a way to help refugees and the world’s poor obtain citizenship and immigration records. Best of all, the security features of blockchain could mean hacking and identity theft will become much harder.

All of this sounds wonderful but horribly complicated. That’s because a viable blockchain ID system would entail coordination among not just businesses and individuals, but also governments--which still possess the ultimate authority to define our official identity. Unfortunately, as my trip to DMV underscored, governments are terrible at technology. This means the dream of “self sovereign identity” could be a long way off.

Surprisingly, one person who agrees is Vinny Lingham, who heads the buzzy blockchain ID startup, Civic. In an interview with Fortune, Lingham acknowledged it could take years for government and industry to agree on a common blockchain standard for identity. And while a startup, uPort, has signed up the Swiss city of Zug to implement a blockchain ID system, he says such examples are outlier cases in the same way Estonia is an outlier when it comes to digital government. It will be much harder for blockchain ID to get traction on a larger scale.

“We looked at blockchain voting, and realized it will take any government of a reasonable size years to implement it. We won’t see elections on the blockchain in the U.S. for at least two more cycles,” said Lingham, adding that using blockchain to help the world’s poor is an admirable but mostly out-of-reach idea for now.

Lingham says adoption of blockchain ID systems is instead going to start with more humble projects, such as vending machines and website log-ins. After that it will spread to applications like social media and dating sites, he predicts. In the meantime, though, it’s going to be slow-going.

“It’s a grind to be honest. Every week we're signing up dozens of users. Hopefully it'll soon be hundreds or thousands a week,” Lingham said, adding blockchain ID projects need to find daily and weekly use cases to be viable.

The bottom line is blockchain-for-identity is more than a pie-in-the-sky vision but, for the foreseeable future, our driver’s license is going to remain our primary form of ID.

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