TL;DR
A multi-sig wallet requires multiple private keys to authorize a transaction, ensuring no single person can unilaterally move funds — commonly used for project treasuries and team wallets.
A multi-sig is configured with N total signers and a threshold M (e.g., 3-of-5). Any transaction from the wallet requires at least M signatures from the N authorized signers. If set to 3-of-5, three out of five team members must approve a transaction before it executes. This prevents single points of failure — if one key is compromised or one team member goes rogue, funds remain safe.
Squads Protocol is Solana’s leading multi-sig solution, used by hundreds of projects for treasury management, program upgrades, and team operations. Squads provides a web interface where signers review and approve transactions. It also supports program upgrade authority management — ensuring protocol upgrades require multiple team members’ approval. Other options include SPL Governance and custom multi-sig programs.
When evaluating a project’s trustworthiness, check if its treasury and program upgrade authority use a multi-sig. A project where one wallet controls millions in treasury or can upgrade the smart contract unilaterally is higher risk. Multi-sig adoption signals that the team takes security seriously and has distributed control. Look for this information in project documentation or on-chain by checking the upgrade authority of the program.