Signal and Threema Decline WhatsApp Interoperability
According to new EU legislation, Meta* is required to make its messaging apps compatible with other services by March 2024. However, the popular messengers Signal and Threema have announced that they do not plan to connect to WhatsApp’s third-party chat feature, citing the need to maintain a high level of user privacy and security.
EU’s Digital Markets Act and Meta’s Response
Under the Digital Markets Act (DMA), Meta must “be ready to ensure interoperability with other services within three months of receiving a request.” The company itself notes that the actual public rollout of interoperability features may take longer.
In the first year of the DMA’s implementation, only personal third-party chats—including file, image, video, and voice message exchanges—are required to be supported. Later, this support must extend to group chats and calls as well.
Previously, Meta stated that developers of third-party messengers would need to sign an agreement to interact with Messenger and WhatsApp before jointly implementing interoperability features.
Encryption Standards and Privacy Concerns
Meta is asking other providers to use the WhatsApp Signal encryption protocol but says it is also willing to work with other protocols if they meet the same security standards. Meta promises to provide end-to-end encryption (E2EE) regardless of the chosen protocol.
However, the two leading secure messaging platforms—Signal and Threema—have made it clear that they are not interested in interoperability with WhatsApp. They emphasized that user privacy and security are their top priorities, even if it means missing out on expanding their user base through compatibility with WhatsApp.
Signal President Meredith Whittaker stated: “Our privacy standards are extremely high, and not only will we not lower them, but we want to continue raising them. Currently, working with Facebook* Messenger, iMessage, WhatsApp, or even the Matrix service would mean lowering our data protection standards.”
A Threema representative expressed a similar view: “The main reason is that our security and privacy standards are incompatible with theirs. We cannot and will not deviate from these standards—that’s the whole point of Threema.”
Metadata and Open Source Issues
Although WhatsApp chats are fully encrypted using the same Signal protocol as Signal and Threema, WhatsApp does not offer advanced protection for metadata. While metadata does not contain message content, it is still valuable and potentially sensitive, as it reveals who is communicating with whom and when. Since WhatsApp’s source code is closed, Signal and Threema argue that developers cannot know what else might happen to their users’ data once it enters WhatsApp’s ecosystem.
Global Interoperability and Telegram’s Position
It also remains unclear whether WhatsApp will open interoperability to competitors worldwide or restrict it to EU countries only, as Apple did with a special version of iOS 17.4 that allows alternative app stores exclusively in the EU.
As of now, one of the world’s most popular messengers—Telegram, whose user base exceeds the combined audience of Signal and Threema—has not released an official statement about its plans for chat compatibility with WhatsApp.
* Meta and its products are designated as extremist and their activities are banned in Russia.