I've never understood the origins of this argument. I'm pretty sure it's rooted in deep misunderstanding.

If I want to spam you I buy a bunch of numbers on Plivo and start sending your number messages with SMS, the existing standard. They show up in iMessage on your phone. The only difference is they're green instead of blue.

So, how do I need an iPhone to send you spam? iMessage doesn't do anything related to spam other than let you delete and report it.

But if it did work that way, then the standard could include that messages need to be signed with a device attestation key from an approved vendor or something like that. There could be a way to have your attestation keys registered like we do for CAs today so that your attestation hardware could be used. Phone manufacturers would all implement device attestation, like Apple and Google do.

Please note I’m responding to the claim that there is “absolutely no downside” to making Apple devices more interoperable. I’m not saying whether or not that is a good enough reason not to.

I know the difference between SMS and iMessage. Currently I get plenty of SMS spam. I get pretty much zero iMessage spam. I’m pretty sure that I would get more spam if iMessage was made interoperable, even if device attestation was implemented as you described. Some Googling suggests that RCS, the competing standard for messaging, does not implement device attestation.

> Please note I’m responding to the claim that there is “absolutely no downside” to making Apple devices more interoperable. I’m not saying whether or not that is a good enough reason not to.

Right, I'm just genuinely confused. How would you meaningfully distinguish between the spam? Why would there be more of it? Wouldn't it just come in blue instead of green? I'm not sure I understand how adding a 2nd avenue for spammers opens new doors when the existing avenue is totally sufficient. Perhaps if you could send messages from an email only account is what you're saying? Personally I would hope there'd be ways to control unsolicited messages in the messaging apps and report spam to the carriers. And honestly I was thinking that as an sms replacement, messages from email-only accounts would be something different carriers would want to gate/control onto the network as they see fit. Or more ideally the protocol itself could require messages to be signed with device attestation keys. Why iMessage doesn't give me better spam management options for existing SMS is the real question.

In the Messages app on iOS, how the message was sent is clearly marked. At the the top of the conversation window, above the chat bubbles, it will say “Text Message” or “iMessage”. This line will also appear between chat bubbles whenever the current thread changes how messages are being sent.

But I think I see the miscommunication. I’m assuming that iMessage gains interoperability and thus there are more people who could potentially send spam. But I think you are arguing that SMS would be replaced with the more advanced, interoperable protocol. In that case, I understand your arguments why there would be the same amount or less spam.

Spam operations have so much money that buying a bunch of iPhones is not an issue, even if they didn't, they could buy older, used iPhones for pennies.

Well then why haven't they? I get zero iMessage spam.

I don't know, I don't get any SMS spam either.

Maybe we are not that interesting?

But I do get a spam call from time to time.

I'll add some anechdata: I get frequent text spam (about 1/day at the peak, it's slowed a lot recently). I've gotten maybe 5 spam iMessage messages during the entire lifetime of my phone.

The bigger headache is the iCloud account required to send iMessages. A pain to set up, and after a few spam messages Apple will just terminate the account. And probably blacklist the phone used to do it. Sure, this isn't terribly expensive, but compared to the barrier of entry to SMS (zero), it is pretty substantial.