Toby Sharp joined Brink engineers to present Hornet, an executable specification for Bitcoin consensus.

In his presentation, he discussed:

• “The code is the spec”
• How Hornet differs from libbitcoinkernel
• Properties of a good specification
• The 35 semantic rules that define block validity
• A declarative C++ implementation of the rules
• A custom UTXO database designed for Bitcoin
• Approaches to block validation
• Ideas of a domain specific language (DSL) for consensus
• Differential and adversarial testing
• Q&A with the audience