Web3 changes the security model. In a traditional service, a provider may be able to reset an account, stop a transfer, or reverse an error. With a self-custodial wallet, control rests with the person or team holding the recovery phrase and signing keys. That control is powerful, but it turns a deceptive request into a potentially irreversible decision.
Most Web3 losses do not begin with someone “breaking the blockchain.” They begin with trust: a copied website, a fake support account, a malicious browser extension, a compromised team chat, a request for a secret recovery phrase, or a transaction approval that hides what it will actually do.
The first rule is absolute: never share a secret recovery phrase or private key. A recovery phrase is not a support code. It is the master credential that can recreate the wallet and control its accounts. MetaMask states that its team will never ask for it. Do not paste it into a website, send it through email or chat, photograph it for cloud storage, or reveal it to someone offering urgent support.
Store recovery material offline with a method appropriate to the value at risk. For an organisation, one person should not silently hold every key. Use documented custody, separation of duties, secure backups, and approval policies. High-value treasury activity should use hardware-backed signing and, where appropriate, multisignature controls so a single compromised device or employee cannot move everything.
Separate identities and wallets by purpose. A wallet used to explore new applications should not also hold treasury assets or control production contracts. Use distinct wallets for browsing, routine operations, administration, and long-term holdings. Apply the same principle to email accounts and browser profiles. Segmentation limits the damage when one environment is compromised.
Verify the destination before connecting. Phishing domains can reproduce a real application almost perfectly. Reach important services through a trusted bookmark, not a sponsored search result, direct message, or unexpected email. Check the entire domain, not only the logo and page design. Treat urgency, secret rewards, surprise airdrops, and “account recovery” messages as reasons to stop.
Understand what a signature authorizes. A wallet connection may reveal only a public address, but a subsequent signature or transaction can grant powerful permissions. Read the requested network, contract, asset, amount, spender, and approval scope. Avoid blind signing when the wallet cannot explain the outcome. The Ethereum Foundation’s Clear Signing initiative focuses on this structural problem: users need human-readable information at the final approval step.
Use transaction simulation and wallet security warnings when available. These tools can identify known malicious domains, suspicious addresses, or unexpected asset changes before execution. A warning is a signal to investigate, not a prompt to click through. Security tooling cannot guarantee safety, especially for new contracts, so combine it with independent verification.