Top 10 Polymarket Trading Strategies (With Examples)

Solving Damn Vulnerable DeFi V4: Level 4- Side Entrance

A walkthrough of the Side Entrance challenge from Damn Vulnerable DeFi V4, where the goal is to drain a lending pool. The vulnerability is a business logic flaw: the flash loan contract only checks that the pool balance is restored after the loan, but doesn't verify whether funds were returned via deposit (which credits the attacker's balance) rather than a direct transfer. The exploit takes a flash loan, repays it via the deposit function to gain an internal balance, then withdraws and sends funds to a recovery address. A working Solidity proof-of-concept contract and test function are provided.

The AI Agent Can Act On-Chain. Who Defines Its Authority?

When an AI agent can submit state-changing blockchain transactions without per-action human approval, the critical question shifts from capability to authority. The post argues that DAO governance provides the right framework for defining, enforcing, and revoking agent permissions when multiple parties share economic risk. It outlines a minimal authorization layer composed of four elements: explicit machine-readable permission scopes ratified by governance, hard contract-enforced limits that reject out-of-scope actions, fast-path multisig revocation bypassing governance timelocks, and a public on-chain authorization record with action logs. Real-world asset (RWA) tokenization exposes the boundary clearly — a DAO can govern on-chain exposure but cannot control off-chain issuer redemption. Existing standards (ERC-4337, EIP-7702, ERC-7579, ERC-8004) provide infrastructure pieces but no complete mandate. Major protocols like Aave, Arbitrum, and Uniswap have governance machinery that could be extended, but none currently publish a complete agent authorization process. The authorization record can prove what was permitted and logged, but cannot validate oracle integrity, custodian reserves, or legal compliance.

I Watched a Contract Rob Itself of $50M. Nobody Hacked It.

Smart contracts are blind — they rely entirely on external price oracles to make financial decisions. This creates a critical attack vector: oracle manipulation. By combining flash loans with spot-price oracle reads, an attacker can borrow millions, artificially inflate a token's price in an AMM pool within a single atomic transaction, drain a lending protocol's treasury using the fake price as collateral, then repay the flash loan — all without breaking any rules. The contract robs itself. TWAP oracles slow this attack but don't eliminate it on low-liquidity tokens. Real defenses require decentralized oracle networks aggregating many sources, circuit breakers that halt on abnormal price deviations, and cross-checking two independent oracles so an attacker must corrupt multiple data sources simultaneously.

The Ledger Unmasked: The Role of Blockchain Explorers in Cryptocurrency Investigations

Blockchain explorers are far more than simple transaction lookup tools — they serve as the primary forensic interface for cryptocurrency investigations. This deep-dive covers how explorers index raw blockchain data, the differences between UTXO (Bitcoin) and account-based (Ethereum) forensic paradigms, transaction graphing and hopping analysis to trace illicit funds, de-anonymization via behavioral heuristics and temporal metadata, smart contract and DeFi exploit auditing, cross-chain capital flow tracing across bridge infrastructure, and how explorer data integrates into enterprise forensics and legal frameworks as immutable evidence.

The First Thing I Check When I See Division in Solidity

Khi kiểm toán hợp đồng thông minh Solidity, việc đầu tiên cần xem xét là phép chia nguyên (integer division) vì nó tự động cắt bỏ phần dư, dẫn đến lỗi chính xác có thể ảnh hưởng đến lợi ích người dùng. Các mẫu dễ bị tấn công thường gặp trong tính toán phần thưởng hoặc tỷ lệ chia sẻ, và giải pháp thường là sắp xếp phép nhân trước phép chia.

Một lập trình viên nên đọc bài này để tránh các lỗi precision không mong muốn trong các tính toán chia nguyên số trong Solidity, đặc biệt khi thiết kế hệ thống phân phối thưởng, lợi nhuận hoặc các giao dịch quy mô lớn.