Presentation: Practical Blockchains: Building on Bitcoin



1:40pm - 2:30pm

Day of week:



Key Takeaways

  • Gain deeper insight into blockchain technology
  • Learn a simple framework to evaluate blockchain products for fit to your use case
  • Understand how blockchain/bitcoin can be applied in your day to day development


Talk will answer the questions:

  • Why use Bitcoin over other blockchains
  • What are safe, future proof ways to peg data to Bitcoin's blockchain
  • What is Bitcoin script, and how can it be used?


Can you tell me about the work you’re doing today?

I’m a bitcoin core developer, but, really, the type of work I’m really focused on these days is somewhere between research and education. What’s interesting about the combination of research and education is that it’s sort of like UI/UX design for programmers.

What do I mean by that? One of the big challenges in making use of blockchain tech is figuring out ways to get people to work with it (to interact with and use it). That is essentially a UI/UX problem. It’s very similar to how programming language design is also a UI/UX problem.

What is the fundamental thing blockchain tech does for us?

Blockchain helps us answer questions like: what are you trying to prove, and what are you trying to disprove. In some cases (not all cases), you can use the bitcoin blockchain to prove facts about other datasets.

A typical thing you might want to prove is the fact that there’s only one version of this dataset. The fundamental thing that blockchain tech does that is unique in encrypto is it makes things unique and globally consistent.

It’s kind of like selling your house. I can give you the contract and all the contracts leading up to it (including the chain of people who sold it prior to the last one). What cryptography can do is verify each one of the contracts by itself is valid, but what cryptography (by itself) doesn't tell you is was the house ever sold twice? Did I simultaneous make another contract while making a contract with you? So it’s not enough to show that the rules were followed, you also have to show that this version of history (or series of events) are unique.

Blockchains can do exactly this because they are methods of leveraging consensus.

What’s the goal for your talk in London?

I think I’d really like to focus on demystifying the blockchain. From there, I’d like to focus on how bitcoin is one way of providing an additional leg of security (it’s certainly not the only way), but it’s probably the most common one used right now. My goal would be to help developers understand how blockchain tech can apply to their day to day.

You talk about a framework for evaluating blockchain products. What does that look like?

It’s easier than people might realize. The purpose of most software is to let you do things. The purpose of Photoshop is to let you do great things with images. Security software is all about preventing bad things from happening.

Yes, security software let’s you do something, but the thing that makes it different than normal software is what it stops. So you’re evaluation process for any solution has got to start with: what am I trying to allow to happen, and what am I trying to prevent from happening?

Once you're clear on that then you can look at the proposed solution and start talking about capabilities. You can ask yourself does it prevent the things I want prevented. It’s really as easy as that.

What do you want the audience to leave with?

I think the big thing I want them to leave with is I want them to be able to evaluate potential blockchain solutions. If someone presents ethereum or bitcoin for applications. I’d like the audience members to ask the right questions to evaluate it. What a blockchain needs and how it relates to your problems. If I can do that, I think the talk is a successful talk.

Speaker: Peter Todd

Bitcoin Core Developer & @Coinkite Advisor

Peter is an independent applied cryptography consultant - what the cool kids call "blockchain tech" - known for his research and educational work on better understanding and making use of "blockchain" technology, with a particular focus on scalability. He's also a long time contribution to Bitcoin Core, as well as maintainer of the python-bitcoinlib and OpenTimestamps projects. He brings to this field a very diverse background, including a fine arts degree, and a stint doing analog electronics design for a geophysics startup.

Find Peter Todd at

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