Our support team get asked this question a lot. Especially now with all of the media coverage surrounding the use of Signal.
Our answer? iMessage. Not Signal. Not Threema. Not WhatsApp.
Why? Most top messengers (except Telegram!) offer strong end-to-end encryption, but encryption isn’t the real battleground anymore-remote exploitation is.
Attackers don’t crack encryption; they hack the device directly using 0-click, 0-day exploits delivered via messaging apps. Then they can read all of your messages, decrypted as they sit on the device.
iMessage + Lockdown Mode = Unmatched security. When enabled, Lockdown Mode hardens iMessage (and FaceTime) against these attacks by reducing the attack surface when processing inbound, potentially malicious, messages.
Other messaging apps do NOT get these extra protections from Lockdown Mode.
To maximize security:
- Use iMessage (blue bubbles)
- Enable Lockdown Mode
- Turn on iMessage Contact Key Verification
Historically, Signal led the way in encryption, but with Apple’s iMessage encryption upgrades last year, that advantage is now gone.
Caveat: This works only if everyone in the conversation is on Apple devices, otherwise messages to Android devices will be unencrypted entirely.
Most of our government clients that are on iOS only use iMessage + Lockdown Mode for messaging for this reason and, on official devices, block all other messaging apps to reduce the attack surface. Some use in-house developed messaging apps that outsiders (and attackers) cannot easily join to make it difficult for them to even send a malicious message to a victim in the first place.
