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Presentation: Blockchain Introduction: Peering Through the Hype

Track: Practical Cryptography & Blockchains: Beyond the Hype

Location: Mountbatten, 6th flr.

Day of week:

Slides: Download Slides

Level: Intermediate

Persona: Developer

What You’ll Learn

  • Understand the data structure that makes a blockchain a blockchain
  • See whether or not blockchain technology is appropriate for what you are doing or the application that you want
  • Learn about the purpose behind bitcoins mining and how all the different aspects of blockchain work together to improve data security


Will answer the questions: what is a blockchain, why all the hype, what makes a blockchain secure, what can be built on top of blockchains, what are some real-world use-cases?


QCon: What are smart contracts?


We use smart contracts as computer executable code that performs the tasks and provisions that would be described in a real world legal contract. The intention is that it runs in an auditable place to ensure the integrity of this software contract.


QCon: Does it have to have an exchange or can it run peer to peer?


It can run peer to peer but then it requires that the counterparties trust each other not to alter the contract in some way. Smart contracts can be running at thousands of nodes all over the world so you want to be sure that the code that is intended to run is indeed the code that is running.


QCon: What will your talk at QCon be about?


Blockchains received a lot of hype. They’ve been proposed to solve problems like financial and storing data. The focus of my talk is to explain what blockchain technology is and why the evolved into bitcoin and distributed currency.

I want the audience to understand whether or not this technology is actually appropriate for what they are doing or the application that they want.


QCon: Can you give an example of the perfect use case for the blockchain, and what isn’t?


Bitcoin is a basic use case where blockchain was invented; it’s a way to record the transaction history of everyone who has ever sent bitcoins from one person to another person. As they are stored on thousands of nodes all over the world there’s a permanent record of the transaction history which makes it a currency.

One bad use case that I’ve seen is trying to track supply chains. For example a manufacturing company might want to track a product through manufacturing, shipping and distribution and they want to make sure that the items location is known at every point in time. It’s a bad application because you are relying on someone accurately transcribing information, on the human sphere onto the blockchain. If you are trusting humans to transcribe information then you might as well have them use their own database.


QCon: How would you rate the level of this talk?


It will be introductory enough so that anyone with a general understanding of how computer systems work would be able to understand it.

Speaker: Elaine Ou

Security Engineer @GlobalFinancialAccess & Co-Creator of Sand Hill Exchange

Elaine is an engineer at Global Financial Access, a company that works on cryptographic integrity for smart contracts. She is a core developer for Ethereum Classic and contributor at Bloomberg View. Previously she was co-founder of Sand Hill Exchange, a Bitcoin bucket shop.

Find Elaine Ou at

Preliminary tracks

Discover some of the topics you will see at QCon London. *The schedule is subject to change

Event-Based Architectures: The Hard Parts

Architectures You've Always Wondered About

Building High Performing Teams

Scaling Security, from Device to Cloud

From Remote to Hybrid Teams: Return to Office?

Performance/Mechanical Sympathy

Next Generation Microservices: Building Distributed Systems the Right Way

Modern Data Pipelines & Streams

The Cloud Operating Model

Chaos and Resilience: Architecting for Success

Scaling Frontend

Modern JVM Innovations

MLOps: Implementing ML Across the Enterprise

Architecting a Modern Financial Institution

Crafting the Developer Experience