Lending Protocol
A lending protocol is a DeFi application that lets users supply assets to earn interest and borrow assets against collateral, with solvency enforced by smart contract invariants and liquidation mechanisms.
In Depth
Lending protocols like Aave and Compound form the backbone of DeFi. Users deposit collateral and borrow against it, earning interest from borrowers. Smart contracts manage the whole process without intermediaries. These protocols must maintain strict solvency invariants: total collateral value must always exceed total debt, and liquidations must fire before positions go underwater. The attack surface is wide. Oracle manipulation can distort collateral valuations, and rounding errors in interest accrual can leak value over time. Flash loan attacks can also exploit liquidation logic. Testing lending protocols requires verifying solvency properties across millions of borrow, repay, and price-change sequences. That's exactly what invariant testing does best. Recon's DeFi security audit services cover lending-specific threat models including bad debt accumulation and interest rate manipulation.
Frequently Asked Questions
What is a lending protocol?
A lending protocol is a DeFi application where users deposit crypto assets to earn interest, and borrowers take loans by posting collateral. Smart contracts handle deposits, withdrawals, and liquidations automatically. Aave and Compound are the most widely used examples.
What security risks do lending protocols face?
Lending protocols face oracle manipulation that distorts collateral prices and bad debt from failed or delayed liquidations. Flash loan exploits can bypass solvency checks, and rounding bugs leak value over time. Invariant testing can verify that solvency properties hold across all possible transaction sequences.