The Handoff: Learning to Build Safely

Lesson 1 opens on

Value DeFi, November 2020

Value DeFi had boasted publicly of its defenses: the day before the exploit it posted a Twitter thread highlighting its flash-loan exploit prevention methodology, an assurance made for users to read.' The bug was not novel or deep; it was the standard oracle-manipulation pattern the field already understood and had documented, in new vault code that, by the team's own post-mortem, had not been audited. What made it possible was not that the attack was clever but that the team was confident, confident enough to advertise a safety property it had not actually established, and to build on an oracle it did not fully understand.