Device and Account Hygiene

12.1 The weakest link

After two chapters on scams, Mint asked a practical question. "I understand the scams now. But what should I actually do, day to day, to stay safe?"

"Think of security like hygiene," said Hash. "You don't wash your hands because you're sure you'll get sick today. You do it every day because it quietly prevents problems. Crypto security works the same way. A few simple habits, done consistently, prevent most of the disasters."

This chapter collects those habits in one place: your wallet structure, your devices, your accounts, and your own discretion.

12.2 Separate wallets for separate jobs

Chapter 2 introduced the three-wallet setup. Here's how it works in practice.

	Vault	Spending wallet	Burner wallet
Purpose	Long-term savings	Everyday use with trusted applications	Experimenting with new, unknown, or risky sites
Typical setup	Hardware wallet or multisig	Software wallet, possibly with a hardware wallet	Software wallet with its own seed phrase
Amount held	Most of your holdings	What you need for regular activity	Only what you're prepared to lose
Connects to applications	Rarely, if ever	Trusted, well-known applications	Anything new
Approvals	Avoid	Reviewed regularly	Assume compromised; check often

Money flows in one direction for safety: from the vault to the spending wallet when needed, and from the spending wallet to the burner wallet for a specific use. If you receive something valuable in the burner wallet, move it to a safer wallet.

One important detail: for real separation, the burner wallet should have its own seed phrase, not just be a second account under the same seed. If a single seed phrase is exposed, every account generated from it is exposed too.

12.3 Your devices

Your wallets are only as secure as the devices they run on.

Keep everything updated. Operating system, browser, and wallet updates often fix security vulnerabilities. Turn on automatic updates.

Install only what you need, from official sources. Every app and extension is a potential risk. Avoid pirated software, game cheats, and "cracked" tools, which are common malware carriers.

Be selective with browser extensions. Extensions can read and change the websites you visit. A malicious or compromised extension can alter what you see on a crypto site. Keep only extensions you trust and use.

Consider a dedicated browser profile for crypto, with only your wallet extension installed and only your bookmarked crypto sites. This reduces the chance of other extensions or tabs interfering.

Lock your devices with a strong PIN, password, or biometrics, and set them to lock automatically.

Don't run files or code from strangers, including "coding tests" from unsolicited job offers, as Chapter 10 warned.

Node had one more question. "Should I have a separate computer just for crypto?"

"For very large amounts, some people do," said Hash. "For most people, a dedicated browser profile, a hardware wallet for the vault, and good habits are enough."

12.4 Your accounts

Even in self-custody, your accounts matter. Your email, phone number, exchange accounts, and cloud storage can all be used against you.

Email. Your email is often the master key to everything else, because it's where password resets go. Use a strong unique password and app-based two-factor authentication or a hardware security key. Consider using a separate email address for crypto services, one that isn't publicly associated with you.

Phone number. As Module 1, Chapter 12 explained, SIM swap attacks let criminals take over your phone number and intercept SMS codes. Avoid SMS-based two-factor authentication where possible, and ask your mobile carrier whether it offers extra protection, like a port-out PIN.

Passwords. Use a unique password for every service. A password manager is a good tool for this, just not for your seed phrase, as Chapter 3 discussed.

Two-factor authentication (2FA). Use an authenticator app or hardware security key on every exchange and important account. Back up your 2FA recovery codes securely, so you don't lock yourself out.

Account	Main risk	Protection
Email	Password resets for everything else	Unique password, app or hardware key 2FA, separate crypto email
Phone number	SIM swap, intercepted SMS codes	Avoid SMS 2FA, carrier account protection
Exchange accounts	Account takeover	App or hardware key 2FA, withdrawal whitelists
Cloud storage	Stored photos or documents exposing secrets	Never store seed phrases there; strong 2FA

12.5 Your bookmarks

This habit is so simple it's easy to underestimate. Save verified bookmarks for every exchange, wallet website, and application you use. Then always use the bookmark, never search results, ads, or links in messages.

Many of the phishing attacks in Chapter 10 rely on you arriving at a site through a search or a link. Bookmarks remove that path entirely.

12.6 Your public footprint

Crypto security isn't only digital. The less people know about your holdings, the less you're a target.

Avoid posting portfolio screenshots, wallet balances, or large gains publicly. Be careful about linking your real identity to wallet addresses, for example through public profiles or domain names, since anyone can then see your holdings, as Module 1 explained. Be cautious discussing your holdings with people you don't know well. And use discretion about wearing or displaying crypto-branded merchandise in contexts where it may draw attention, such as when travelling.

Physical attacks on crypto holders, ranging from robbery to kidnapping, have increased in recent years as values have risen. They remain rare, but discretion is the simplest protection.

12.7 Regular checkups

Hash suggested a monthly routine that takes about fifteen minutes.

1. Check token approvals on each network you use and revoke anything unnecessary (Chapter 8).
2. Review connected sites in your wallet and disconnect old ones.
3. Check that your devices, browser, and wallets are updated.
4. Review your browser extensions and remove any you don't use.
5. Check your exchange accounts for unfamiliar logins or withdrawal addresses.

And a yearly routine:

1. Confirm your seed phrase backups are where you expect, readable, and match your wallets (Chapter 4).
2. Update your inheritance letter if your setup has changed.
3. Consider whether your security still matches the amount you hold.

12.8 Proportion matters

"This is a lot," said Mint.

"It's a menu, not a requirement," said Hash. "Someone holding $100 needs a well-protected seed phrase, app-based 2FA, and bookmarks. Someone holding life savings should use most of this chapter. Start with the basics, and add layers as your holdings grow."

Holdings	Sensible minimum
Small, learning amounts	Written seed phrase backup, app-based 2FA, bookmarks, burner wallet for experiments
Meaningful amounts	Add a hardware wallet vault, separate crypto email, regular approval checks, metal backup
Large amounts	Add multisig or advanced custody, multiple backup locations, inheritance planning, dedicated device or profile

12.9 Try it yourself

Do the monthly checkup from section 12.7 today. Write down how long it took and what you found. Then set a recurring calendar reminder for the same day each month.

If you don't already have one, create a burner wallet with its own seed phrase and use it the next time you try a new application.

Key takeaways from this chapter

1. Security is a set of daily habits, not a one-time setup.
2. Separate wallets by purpose: a vault, a spending wallet, and a burner wallet with its own seed phrase.
3. Keep devices updated, install software only from official sources, limit browser extensions, and consider a dedicated crypto browser profile.
4. Protect email and phone accounts carefully, since they can be used to take over other accounts. Avoid SMS-based 2FA.
5. Use verified bookmarks for every crypto site.
6. Keep a low public profile about your holdings to avoid becoming a target.
7. Run a short monthly checkup and a yearly backup review, matching your security to your holdings.