Security guide
Crypto Security Guide
A practical crypto security guide: what a blockchain wallet is, how to secure it, how to spot scam wallets and vet counterparties, and how projects stop Sybil attacks.
What is a blockchain wallet?
A blockchain wallet does not hold coins. It holds the private key that proves you control an address on the chain. Anyone with that key, or the seed phrase that creates it, controls the funds.
Hot wallets (browser and phone apps) are always online and convenient. Cold wallets (hardware devices) keep the key offline and are safer for larger amounts.
How to secure your crypto wallet
Most losses come from leaked seed phrases, malicious approvals and fake sites, not from broken cryptography.
- Write the seed phrase on paper or metal. Never type it into a website, chat or screenshot.
- Use a hardware wallet for savings and a separate hot wallet for daily use.
- Bookmark the real sites you use and open them only from the bookmark.
- Review and revoke old token approvals regularly.
- Read what you sign. A signature request can move assets just like a transfer.
- Keep an encrypted backup and a tested recovery plan.
How to spot scam wallets and fake airdrops
Scam wallets often have a short history, receive funds from many fresh addresses and move them out fast. Fake airdrops ask you to connect and sign before showing anything real.
A reputation check is a signal, not a guarantee: when there is not enough history, the honest answer is “insufficient data”.
Trading safely with people you don't know
Before a P2P trade or OTC deal, check the other wallet's history, ask for a signed message proving ownership, and start with a small amount.
What is a Sybil attack?
A Sybil attack is when one person runs many fake identities to look like a crowd — to farm airdrops (“sybilling”), swing DAO votes or drain grant rounds.
Sybil resistance mixes signals: wallet history, graph clustering, proof of personhood and peer vouching. No single signal is perfect.
For projects: Sybil-proof airdrops and funding
Set eligibility rules before the snapshot, combine several signals, and give real users a way to appeal.
Proof of personhood
Proof of personhood shows an account belongs to a unique human without exposing who that human is.
FAQ
What is the most secure crypto wallet setup?
A hardware wallet for savings, a separate hot wallet for daily use, an offline seed phrase backup, and regular approval reviews.
Can a wallet score prove someone is honest?
No. It is a heuristic based on public on-chain activity. Use it as one signal, and treat “insufficient data” as unknown, not safe.
How do I prevent a Sybil attack on my airdrop?
Combine wallet history, cluster analysis and a personhood or vouching signal, publish the rules before the snapshot, and offer an appeal path.
Check a wallet before you trust it
See a wallet's public reputation signals on TrustLayer.
Open the wallet checker →