Every internet user should have the ability to privately communicate with the people that matter to them, in a secure fashion, using the tools and protocols of their choosing.

Apple’s iMessage offers end-to-end encrypted messaging for its customers, but only if those customers want to talk to someone who also has an Apple product. When an Apple customer tries to message an Android user, the data is sent over SMS, a protocol that debuted while Wayne’s World was still in its first theatrical run. SMS is wildly insecure, but when Apple customers ask the company how to protect themselves while exchanging messages with Android users, Apple’s answer is “buy them iPhones.”

That’s an obviously false binary. Computers are all roughly equivalent, so there’s no reason that an Android device couldn’t run an app that could securely send and receive iMessage data. If Apple won’t make that app, then someone else could. 

That’s exactly what Apple did, back when Microsoft refused to make a high-quality MacOS version of Microsoft Office: Apple reverse-engineered Office and released iWork, whose Pages, Numbers and Keynote could perfectly read and write Microsoft’s Word, Excel and Powerpoint files.

Back in September, a 16 year old high school student reverse engineered iMessage and released Pypush, a free software library that reimplements iMessage so that anyone can send and receive secure iMessage data, maintaining end-to-end encryption, without the need for an Apple ID.

Last week, Beeper, a multiprotocol messaging company, released Beeper Mini, an alternative iMessage app reportedly based on the Pypush code that runs on Android, giving Android users the “blue bubble” that allows Apple customers to communicate securely with them. Beeper Mini stands out among earlier attempts at this by allowing users’ devices to directly communicate with Apple’s servers, rather than breaking end-to-end encryption by having messages decrypted and re-encrypted by servers in a data-center.

Beeper Mini is an example of “adversarial interoperability.” That’s when you make something new work with an existing product, without permission from the product’s creator.

(“Adversarial interoperability” is quite a mouthful, so we came up with “competitive compatibility” or “comcom” as an alternative term.)

Comcom is how we get third-party inkjet ink that undercuts HP’s $10,000/gallon cartridges, and it’s how we get independent repair from technicians who perform feats the manufacturer calls “impossible.” Comcom is where iMessage itself comes from: it started life as iChat, with support for existing protocols like XMPP

Beeper Mini makes life more secure for Apple users in two ways: first, it protects the security of the messages they send to people who don’t use Apple devices; and second, it makes it easier for Apple users to switch to a rival platform if Apple has a change of management direction that deprioritizes their privacy.

Apple doesn’t agree. It blocked Beeper Mini users just days after the app’s release.  Apple told The Verge’s David Pierce that they had blocked Beeper Mini users because Beeper Mini “posed significant risks to user security and privacy, including the potential for metadata exposure and enabling unwanted messages, spam, and phishing attacks.”

If Beeper Mini indeed posed those risks, then Apple has a right to take action on behalf of its users. The only reason to care about any of this is if it makes users more secure, not because it serves the commercial interests of either Apple or Beeper. 

But Apple’s account of Beeper Mini’s threats does not square with the technical information Beeper has made available. Apple didn’t provide any specifics to bolster its claims. Large tech firms who are challenged by interoperators often smear their products as privacy or security risks, even when those claims are utterly baseless.

The gold standard for security claims is technical proof, not vague accusations. EFF hasn't audited Beeper Mini and we’d welcome technical details from Apple about these claimed security issues. While Beeper hasn’t published the source code for Beeper Mini, they have offered to submit it for auditing by a third party.

Beeper Mini is back. The company released an update on Monday that restored its functionality. If Beeper Mini does turn out to have security defects, Apple should protect its customers by making it easier for them to connect securely with Android users.

One thing that won’t improve the security of Apple users is for Apple to devote its engineering resources to an arms race with Beeper and other interoperators. In a climate of stepped-up antitrust enforcement, and as regulators around the world are starting to force interoperability on tech giants, pointing at interoperable products and shouting “insecure! Insecure!” no longer cuts it. 

Apple needs to acknowledge that it isn’t the only entity that can protect Apple customers.