The messaging world has moved from desktop to mobile, to secure mobile messengers for consumer, and to less secure messengers that work on multiple platforms for business.
The future requires a model that combines security for multi-device communication on all platforms-desktop, mobile, tablet, smart devices and wearables. Phone number-based identity is not a good foundation for this future.
All messengers on the market have made two fundamental decisions. First, do they use end-to-end encryption (E2EE) that is on by default or not, and second, are they primarily mobile focused and rely on a phone number, or do they offer a good multi-device experience that is decoupled from the phone number.
From the chart above it's clear that apps like WhatsApp and Signal are in the secure, mobile-first corner. They use a phone number as the account identifier, and require access to the phone address book to operate.
Mostly team collaboration tools like Skype for Business, Microsoft Teams, Slack, but also Facebook Messenger, are in the "not secure by default, but works equally on desktop and phone" corner. They don't offer end-to-end encryption (with the exception of FB Messenger that has it as an option only on mobile and only for 1:1 chats) and keep the content of the conversations on their servers.
Wire's goal is to combine end-to-end security that's becoming the norm in the consumer space, with the workplace must-have features like multi-device support and a great group collaboration experience. This means we've had to do things differently.
Wire needs certain data to operate its service
To provide secure chat, calls, and file sharing, and to offer a great user experience, Wire has some data about its users on the server. This data includes things like profile name, username, and profile picture, but also things like user's list of connections and conversations.