'We can do things now we couldn’t in 2009’: A leading cryptographer explains what blockchain offers us – and what it doesn’t

Market observers continue to debate whether blockchain is an overinflated myth or a legitimate revolution.

But someone who may be able to cut through the fog is Sharon Goldberg, Boston University cryptography professor and security startup co-founder. Having entered the field long before blockchain exploded on the scene, Goldberg has witnessed the "before and after" effect of a technology that has captured public attention.

A cryptographer by training, Goldberg tells The Block exactly what she thinks blockchain can (and can't) do, and why she's committed to seeing the space develop. The below summary has been adapted for brevity and clarity.

What got you into cryptography?

I decided to take a cryptography class during my PhD at Princeton and fell in love with the field for two reasons. First, it's precise. It gives you a way to think about security in a very, very precise way. I also went to a cryptography conference where around 30% of the attendees were women. It was wonderful to see, it was a really welcoming environment.

Why blockchain specifically?

The blockchain space is one of a small set of problems that cryptographers look at, where mutually distrusting parties are trying to accomplish some goal. With blockchain, the interesting cryptographic thing is that you don’t need to trust a third party - blockchain is there as a source of trust.

Can you summarise your take on DLT's potential? Has the hype gone too far?

People are overextending the uses of a blockchain. For instance, the question of how do I bind my identity. Even if I have a cryptographic key – how do I prove it's me and not someone else just using it? Solving it is very hard and involves [error-prone] humans. People are assuming blockchain is going to take away this problem. But mapping an identity in the real world to the digital world is very hard. You can’t just say "blockchain" and have it be the solution.

Saying that, there's a lot of stuff that we just couldn’t do before 2009 [Satoshi's whitepaper]. I like the supply chain example. For example, tracking a mango. That involves various actors, suppliers, and companies. People say we could use a database – but who’s going to run it and who’s going to maintain it? Also, their incentives are not always aligned, so they could erase or change something on a shared spreadsheet. Whereas on a blockchain, you can’t erase things. The key thing is no central party needs to be trusted; all companies involved in the movement of the mangoes would be verifying the blockchain.

What do you think the public should know about blockchain tech?

That it's a technology breakthrough. They may not like what it does in terms of its electricity and environmental cost. But we can do things we couldn't do before.

The way it impacts people's lives will depend on what's next. There are these shortcuts that people assume it can make, but it's not at all clear if those will work. Still, it will become deeply embedded in a lot of systems, maybe in ways that we don't expect.

What are the technology’s main limitations?

The complexities! And that leads to vulnerabilities. It's a very immature technology, it's not very stable. There's a lot of bugs.

What are you most excited to see in terms of its development?

I am most excited about Layer 2 technically and interoperability. I like building systems on top of other systems.

Is there a key area of consensus among cryptographers when it comes to blockchain (if any!)?

Yes, what blockchain solves is that you don't need permission to participate in protocols that allow for agreement among mutually untrusting parties. That's what cryptographers say a blockchain is.