What is the Contact key verification?

iMessage Contact Key Verification is an additional security feature designed to enhance the safety of your iMessage conversations. Here’s how it works:

End-to-End Encryption: When you use iMessage, your messages are end-to-end encrypted, ensuring that only you and the intended recipient can read them during transit between devices. Not even Apple has access to the content.

Contact Key Verification: This feature further protects your iMessage conversations by automatically verifying that you’re messaging with the intended person. If there’s an error in this verification process (for example, due to a sophisticated attacker), you’ll receive an alert.

Manual Verification: You can also manually verify contacts by comparing verification codes. When you manually verify a contact, the system ensures that the saved code matches the one provided by iMessage servers for that contact. If the verification code changes, you’ll be notified.

Requirements:

1.iOS 17.2, watchOS 9.2, and macOS 14.2 on all devices where you’re signed in to iMessage with your Apple ID.

2.iCloud Keychain enabled on all devices.

3.Two-factor authentication for your Apple ID.

4.A passcode or password for all your devices.

5.Note that Managed Apple IDs are not supported.

6.How to Enable:

Open the Settings app (or System Settings on Mac).

Select your name.

Scroll down and tap Contact Key Verification.

Turn on Verification in iMessage and tap Continue.