Protecting Against SIM Swap Attacks

How a SIM swap attack works

A SIM swap attack tricks or social-engineers a mobile carrier into transferring a victim's phone number to a SIM card the attacker controls, letting the attacker intercept SMS messages and calls — including SMS-based two-factor authentication codes.

Why this specifically threatens crypto accounts

If an account uses SMS-based 2FA or phone-based account recovery, a successful SIM swap can let an attacker bypass that protection entirely and potentially take over the account.

Practical protections

• Use an authenticator app or hardware security key instead of SMS-based 2FA wherever possible.
• Set up a carrier-side PIN or additional verification requirement specifically for SIM changes, if your carrier offers one.
• Avoid publicly sharing your phone number in contexts that link it to your crypto holdings or identity.

What to remember

• A SIM swap attack transfers a victim's phone number to an attacker-controlled SIM.
• This can let an attacker intercept SMS-based 2FA codes and account recovery messages.
• Using authenticator apps or hardware keys instead of SMS-based 2FA is a practical protection.
• A carrier-side PIN for SIM changes adds an additional protective layer where available.