Smart Contracts

Discover how smart contracts work, the most common token standards, and real-world use cases that power decentralized application

Hash Functions in Web3 (SHA-256, Keccak-256, Merkle Trees)

Smart Contracts, DeFi & Staking /

Hash Functions in Web3 (SHA-256, Keccak-256, Merkle Trees) Preimage resistance, collisions, avalanche, and how hashes secure blocks, addresses, storage, logs, and proofs across modern chains. TL;DR: A cryptographic hash maps arbitrary data to a fixed-size digest while resisting preimage, second-preimage, and collision attacks. Bitcoin standardizes on SHA-256 (often applied twice), while the EVM stack uses […]

Hash Functions in Web3 (SHA-256, Keccak-256, Merkle Trees) Read More »

Interoperability Protocols (Polkadot, Cosmos/IBC, Wormhole)

DeFi & Staking, Smart Contracts /

Interoperability Protocols: Polkadot, Cosmos (IBC), and Wormhole From shared security and cross-consensus messaging to guardian-signed messages across heterogeneous chains. What each model guarantees, where it is strong, where it fails, and how to build safely on top. TL;DR: Interoperability stacks differ mainly in how they verify foreign state and who bears security. Polkadot couples chains

Interoperability Protocols (Polkadot, Cosmos/IBC, Wormhole) Read More »

Bridges and Cross-Chain Swaps (How Value Moves Between Chains)

DeFi & Staking, Smart Contracts /

Bridges and Cross-Chain Swaps: Lock and Mint, Burn and Redeem, Liquidity Routers How assets and messages travel between chains, what is actually verified, and how swap aggregators compose routes across bridges and DEXs while controlling risk, fees, and finality. TL;DR: Bridges come in two flavors: asset movement and message passing. Asset bridges use lock and

Bridges and Cross-Chain Swaps (How Value Moves Between Chains) Read More »

Multi-sig Wallets (Safe/Gnosis) and MPC Overview

DeFi & Staking, Nodes, L1/L2, Rollups, Security & Best Practices, Smart Contracts /

Multi-sig Wallets and MPC: Shared Control, Fewer Single Points of Failure Set m-of-n approvals for treasury moves, upgrade rights, or personal vault safety. Compare on-chain multisig and MPC, design pragmatic policies, and avoid common operational mistakes. TL;DR: A multisig is a smart-contract account that executes only after m-of-n owner approvals; policy is transparent and enforceable

Multi-sig Wallets (Safe/Gnosis) and MPC Overview Read More »

Decentralized ID (DID) and Verifiable Credentials (VCs)

Smart Contracts, Security & Best Practices /

Decentralized Identifiers (DID) and Verifiable Credentials User controlled identifiers plus portable, signed claims. How DIDs resolve, how credentials are issued and verified, and how these building blocks fit with wallets, apps, security, and compliance. Quick navigation: Introduction • DIDs: formats and methods • Verifiable credentials: model and formats • Issuance flows (wallet and server) •

Decentralized ID (DID) and Verifiable Credentials (VCs) Read More »

Soulbound Tokens (SBTs) Explained

Smart Contracts /

Soulbound Tokens (SBTs): Non-Transferable Credentials for Web3 Identity Degrees, memberships, KYC indicators, and achievements that stick to a wallet. This lesson explains what SBTs are, when they shine, how to design for consent and revocation, and how to pair them with private verifiable credentials for safer real-world uses. Quick navigation: Introduction • Model and motivation

Soulbound Tokens (SBTs) Explained Read More »

Auditing and Testing (Foundry/Hardhat, fuzzing, static analysis)

DeFi & Staking, Security & Best Practices, Smart Contracts /

Auditing & Testing: From Unit Tests to Fuzzing & Invariants Ship with confidence: rigorous tests, automated checks, and structured reviews before mainnet. TL;DR: Use Foundry or Hardhat for unit/integration tests, add fuzzing/invariant tests, run static analysis (Slither), measure coverage, and follow an audit checklist with clear threat models. In this lesson Tooling Stack Foundry Example

Auditing and Testing (Foundry/Hardhat, fuzzing, static analysis) Read More »

Smart Contract Risks Re entrancy, oracle-manipulation

Smart Contracts, Blockchain Basics, Crypto Wallets, Security & Best Practices /

Smart Contract Risks: Re-entrancy, Oracles, Access Control & More Recognize top vulnerability classes and the standard defenses used in production. TL;DR: Most exploits are preventable. Use CEI, ReentrancyGuard, strict access control, safe math by default (>=0.8), and robust oracle design. Test, fuzz, and audit before mainnet. In this lesson Re-entrancy Oracle Manipulation Access Control Math/Overflow

Smart Contract Risks Re entrancy, oracle-manipulation Read More »