Hidden iPhone setting that lets you see if someone is spying on your messages

There's a hidden iPhone setting that lets you see if someone is spying on your messages.

Apple has built a security feature into iPhones that can help detect if someone is intercepting your private iMessage conversations, but most users don't know it exists.

Known as Contact Key Verification, the feature works by generating unique security codes that you can compare with your messaging contacts.

If the codes don't match, it could indicate that your messages are being intercepted – or more innocently, that your contact recently changed phones or reinstalled the messaging app.

iPhones have a security feature that can help detect if someone is intercepting your private iMessages. (hocus-focus/Getty)

How to enable Contact Key Verification

To activate this security feature, open Settings, tap your name at the top, and scroll down to 'Contact Key Verification,' under Settings and Apple ID.

Switch on 'Verification in iMessage,' and tap 'Continue'.

"When you use iMessage, your messages are end-to-end encrypted so that nobody other than you and the person that you're messaging with, not even Apple, can read them while they're in transit between devices," Apple shared.

How to verify contacts

Apple offers two options for verifying that you're messaging the right person.

To do so manually, both you and your saved contact can generate codes simultaneously in your conversation. Open the iMessage thread, tap the contact's name to access Conversation Details, where both parties can generate and compare codes in real-time.

If the codes are the same, you can tap 'Mark As Verified,' which saves the code to that person's contact card.

Someone could be spying on your private messages. (iiievgeniy/Getty)

According to Apple: "When you manually verify a contact, iMessage Contact Key Verification verifies that the code you have saved matches the one provided by the iMessage servers for that contact and notifies you if the verification code changes."

The tech giant added: "iMessage Contact Key Verification further protects your iMessage conversations and helps verify that you're messaging only with the people that you intend."

Another option is to use a Public Verification Code. This allows you to share a verification code that contains no private information, making it safe to post on social media or other public platforms where your contacts can find it.

Once you have their Public Verification Code, you can copy and paste it into their Contact Card.

To do so, open the iMessage conversation and tap the contact's name, or select them from the Contacts app. Then, tap Info and select Edit. In the 'verification code' field, type or paste the relevant Public Verification Code.

If you don't see this field, tap the Add (+) button, choose More Fields, and select 'verification code.'

If the code matches and is verified by iMessage Contact Key Verification, a checkmark will appear on their Contact Card and next to their name in iMessage conversations. This confirms you're messaging the intended person securely.

If no checkmark appears, the code doesn't match or isn't verified. Apple suggests users double-check the code or confirm they're messaging the correct person before continuing any conversations.