Is Your Phone Line Secure?

Your iPhone may be secure, with 7-digit passcode, biometric lock, and Apple’s strong on-device encryption. However is your SIM card secure as well?

If someone stole your iPhone, it may well be they can’t access your data. Thanks to activation lock, they probably won’t be able to re-sell the device as it is – best case is to make use of its screen, battery, and enclosure as spare parts.

But if the stolen iPhone has an unlocked SIM card, it may well be significantly more valuable than the iPhone itself. How? By stealing your identity.

You see, nowadays a cellular phone number is often used as a secondary authentication method for financial transactions, among other things. A SIM card is functionally equivalent to its mobile phone number. Therefore, a perpetrator having an unlocked SIM card would have the opportunity to impersonate that SIM card owner as far as SMS are concerned.

What’s worse is that the identity thief doesn’t really need to steal the SIM card, per se. He/she would just need to “borrow” it – either to temporarily gain access to your identity to perform some undesired transactions, or outright copy the SIM card. Unsolicited borrowing is even better as far as identity theft is concerned, since you don’t know about it and won’t call your telco to invalidate that SIM card.

This is what happened to Emma Franks when she found out that her SIM card was swapped at three days after the event, and lost £1500 in the process. On a totally separate event, a similar modus operandi happened to a senior bank executive and had an unwanted $30K loan made under his name.

You wouldn’t want this to happen to you, would you?

Remember to set a PIN code to your SIM card to lock it. This would prevent unsolicited borrowing, hence would close another attack vector for identity theft.

Here is how you can lock a SIM card on an iOS device:

1. Open the Settings app.
2. Select Mobile Data.
3. Select SIM PIN.
4. Move the toggle in SIM PIN to enabled status.
5. Enter a secure PIN code.

Until next time. Stay safe.