How Block is building AI-powered security with OpenAI technology

At Block, the company behind Square, Cash App, and Afterpay, the security team leverages the OpenAI Defense Factory: where AI handles vulnerability discovery, detection, and response at a scale that no human team could keep up with. With AI systems including OpenAI Daybreak, Block is taking just hours to do work that used to take weeks.

“AI is compressing the time from human intent to action. For a while, it was assumed that there was an attacker advantage since they’re faster and more nimble. But with things like Daybreak and the advancements in OpenAI’s tooling, defenders are able to fight fire with fire and keep up with the rapid pace of AI adoption.”

—James Nettesheim, Chief Information Security Officer, Block

Block’s security team has been focused on responsibly adopting AI across workflows, whether that’s code generation or security operations. “What it’s really centered on is having a new teammate that you can scale with,” James Nettesheim, Chief Information Security Officer, says. “It’s not like a more traditional automation where you had to go step by step. You can prompt it with a fairly bespoke, ambiguous problem and work through it together.”

Projects like reviewing a software bug or parsing a log would take days or weeks to complete. Now the team can complete those projects in a fraction of the time, with a human still validating every result.

For example, for detection tuning, every investigation stores its raw query evidence, so the team can now replay a proposed detection change against seven months of production telemetry in under an hour. That work used to mean requerying hundreds of old cases by hand, and often it rarely happened in practice since it was so time-consuming.