DeFi security

DeFi protocols fail in ways ordinary software does not: a price that can be moved for the length of one transaction, a vault share that rounds the wrong way, a loan that turns into bad debt between two oracle updates, a governance vote bought for a single block. The code can be correct line by line and the protocol still insolvent.

In this area

Publications: 7
Reading time: 60 min

Primers explain a known class of issue with illustrative code. Analyses synthesise public incidents, standards and papers, each cited.

Publications

7 publications on defi security

These publications work through the economics as well as the code: the formulas, worked numerical examples a reader can recompute, the conditions under which an attack pays, and the defences that change those conditions. They start with oracles and flash loans and continue with lending, vaults, governance and token-level risk.

DeFi Security31 October 202611 min read
Technical analysis
DeFi liquidation risk: health factors, oracle gaps and bad debt
How a lending market decides when a position can be liquidated, how much a liquidator repays and seizes, and when a price gap leaves bad debt. Worked numbers on a model market, compared with Aave v3 and Compound III.
DeFi Security31 October 202612 min read
Primer
Is this token safe? A contract checklist for ERC-20 and SPL tokens
A reproducible method for checking whether an ERC-20 or SPL token can dilute or trap holders: mint, freeze, fee, sell, upgrade and liquidity checks, a worked 99% sell-tax example, and what scanners miss.
DeFi Security31 October 202611 min read
Technical analysis
Flash loan attacks: how they work, what they cost, how to stop them
A flash loan removes the capital barrier from an attack, not the flaw behind it. How the loans work, a fully worked example of the economics, four public incidents, and the defences that change the arithmetic.
DeFi Security13 October 20266 min read
Primer
ERC-4626 vault inflation attacks, and the defences that hold
An empty tokenised vault can be manipulated so that the next depositor receives no shares. Why the arithmetic allows it, and how virtual shares, dead shares and slippage checks close the gap.
DeFi Security11 August 20267 min read
Primer
What it costs to move a price: reasoning about oracle manipulation
Every price source has a cost of manipulation. Protocols are safe only while that cost exceeds what an attacker can extract. A framework for estimating both sides.
DeFi Security14 July 20266 min read
Technical analysis
Governance attacks in DeFi
On-chain governance turns token balances into authority over code and treasuries. How that authority has been borrowed, bought, hidden in proposal payloads and routed around timelocks.
DeFi Security7 July 20267 min read
Technical analysis
Understanding oracle manipulation: designs and their failure modes
Spot prices, time-weighted averages, push feeds and pull feeds fail in different ways. A comparison of oracle designs, the assumptions each makes, and the checks a consuming contract must add.