Formal verification on the XRP Ledger's lending code.

On June 9, Ripple and a research firm called Common Prefix said they are formally verifying XRPL's planned native lending protocol before validators can turn it on.

Standard testing checks the cases a developer expected. Formal verification builds a mathematical model of how the code should behave and proves it cannot reach a broken state. The review already caught rounding errors that compound across loans.

The lending lives inside the base network, not in a separate contract on top. One flaw there reaches every application built on it, so a small accounting error carries a wide blast radius.

Proving a class of bugs cannot happen is stronger than passing the tested cases. It still cannot guarantee the code is flawless, since each proof only covers the model it was given.