Open Letter to the British Government Regarding the Online Safety Bill

In addition to the EU’s so-called “chat control,” there’s another European draft legislation that uses child protection as a pretext for full-scale surveillance of chat communication without probable cause: the UK’s Online Safety Bill. Together with other messaging services, we take a firm stand against this legislative proposal.

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Threema 5.0 for iOS: Fresh, Fast, Modern

Just like you occasionally replace old photos on the wall with new ones, apps also need a fresh touch every once in a while. Now, Threema’s iOS app presents itself in a new look: since the 4.8 update, the user interface has been renewed step by step. With Threema 5.0 for iOS, the complete rewrite of the chat view has now received its finishing stroke.

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New Merch Collection in Celebration of Data Privacy Day

Today is Data Privacy Day, an international event held annually on January 28. Its purpose is to raise the public’s awareness for data protection on the Internet.

To celebrate the occasion, we have launched a collection of privacy-themed apparel and accessories. Here’s a small selection:

Join the movement, and show your support for data protection and privacy with statements like “Regain privacy” or “My data is nobody’s business.” To discover the entire merch collection, please follow this link:

Merch shop


Data Protection Is More Than Just Encryption

Online services have started to realize that more and more users care about privacy. As a result, many put an emphasis on privacy protection in their marketing. More often than not, however, privacy protection is confused with security or, specifically, encryption. While encryption of user content is necessary for comprehensive privacy protection, it is by no means sufficient. If, for example, a chat service end-to-end encrypts the messages users exchange but at same time requires personally identifiable information and collects metadata for marketing purposes, that’s nowhere near comprehensive privacy protection.

Useful, Secure, and Versatile Notes in the Threema App

A group chat with you as the only member? What might sound useless at first is a handy feature in Threema: this “group” can be used as a versatile chat for personal notes. Find out in this blog post in what situations this empty group chat is particularly useful.

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Statement on ETH Findings

Last year, a student at the Department of Computer Science at ETH Zurich wrote his master’s thesis on Threema’s communication protocol. ETH Zurich has now published his work as a paper/preprint. The presented findings have been addressed or no longer apply to Threema’s current communication protocol “Ibex.” None of them ever had any considerable real-world impact.

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A Decade of Seriously Secure Messaging

Exactly ten years ago today, on 12/12/2012, the first ever Threema version was published in Apple’s App Store. We celebrate the tenth anniversary of this historic moment with three birthday presents: a humorous short film recounting Threema’s origin story, a 50% discount on the app, and our extended protocol suite that future-proofs the system for the next decade and further solidifies Threema’s security with the new communication protocol “Ibex.”

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Threema for iOS: Preview of Upcoming Multi-Device Functionality

With the desktop app and the web client, it has been possible to use Threema on the computer for a while now. At the moment, the desktop app and the web client require an active (end-to-end encrypted) connection to the mobile device. To send and receive Threema messages on the desktop even when the mobile phone is turned off, a multi-device solution is in development.

Starting today, a tech preview of Threema 2.0 for desktop is available, which allows iOS users to test the upcoming multi-device functionality ahead of time. To use the responsive new desktop application, which was redesigned from the ground up and is based on a totally new architecture, you will need the multi-device beta version of the iOS app.

Test the multi-device functionality now

At the moment, the tech preview of Threema 2.0 for desktop is only available for iOS, not for Android. In the future, support for multiple linked devices, including tablets and Android devices, is planned.

New Communication Protocol “Ibex” and Extended Protocol Suite

Just in time for the tenth anniversary, Threema introduces “Ibex,” a new cryptographic communication protocol that further solidifies Threema’s time-tested security and future-proofs the overall system. On top of that, the overhauled protocol suite receives additional key components that lay the groundwork for forthcoming features.

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Agree/Disagree Feature for Groups

In a conversation, you nod or shake your head to let others know what you think. In a messenger chat, the thumbs-up or thumbs-down icons are used instead. Threema was the first messenger to introduce the agree/disagree functionality, which allows users to react to incoming messages with approval (thumbs up) or disapproval (thumbs down) without triggering a push notification on the chat partner’s end.

This unobtrusive form of interaction is very popular among many users, and in certain situations, it is the most appropriate form of communication. It also allows those who have deactivated read receipts to acknowledge the receipt of individual messages.

As of now, the popular feature is also available in group chats, where it unfolds its full potential. If every member of a large group were to state their (dis)approval of some message by replying to it, things would get out of hand quickly. Using the agree/disagree feature, however, the group chat stays tidy, and it’s evident at a glance how the group members feel about the message. To see who (dis)agrees with a message, simply tap and hold it, and press “(i)” (on Android) or “Details” (on iOS).

The agree/disagree feature is available starting with Threema 5.0 for Android and Threema 4.8.5 for iOS.

Update/download Threema

Threema for Android Introduces Group Calls

When Threema was first released almost ten years ago, it was a chat-only app. These days, however, many users have come to rely on it for secure and privacy-compliant phone calls, which don’t require to disclose a phone number. Expanding Threema’s feature set further, the 5.0 update allows Android users to conduct audio/video group calls of up to 16 participants.

Just like 1:1 calls, group calls are end-to-end encrypted and meet the regular Threema call’s high level of security. Also in terms of quality, users don’t have to give up what they’re used to: group calls offer the same crystal-clear voice quality and brilliant video quality regular calls are known for.

To initiate a group call, simply tap on the camera icon in the top right corner of the desired group chat. All group members (who use the Android app) will receive a push notification that informs them about the call, and they can join by opening the notification, via the group chat, or from the chat overview.

Besides other changes and additions, the 5.0 update also provides the option to activate “Perfect Forward Secrecy” for messages. More information can be found in this FAQ entry.

Update/download Threema for Android

Threema for iOS will support group calls at a later date.

Plenty of New Features for Threema’s iOS App

A breath of fresh air in Threema’s iOS app: With a host of new features and numerous improvements, the extensive 4.8 update offers even more privacy options and provides better handling of the chat overview. You can now mark chats as private to protect them from prying eyes, set read receipts per contact, and tidy up your chat overview with the new archive feature.

If you use the web client or the desktop app on a regular basis, please read the notice at the end of this post.

Read on…

The Privacy Pledge: An Alternative Vision to Big Tech’s Internet

As demonstrated by our recent candid-camera experiment, people still have a strong desire for privacy. In general, we’re not comfortable disclosing personal information about ourselves and our friends if third parties request it without having a compelling reason.

On the Internet, however, we are often unaware of the extent to which our personal data is collected and the exact purposes it is used for.

Companies that offer their online services free of charge and are funded by selling targeted ads go to great lengths to obscure the fact that user data is systematically collected, compiled into comprehensive user profiles, and, in some cases, shared with third parties. On the websites of such companies, these practices go unmentioned, and in their privacy policies, the relevant clauses are deliberately scattered across several paragraphs and written in incomprehensible language full of cryptic jargon. What’s more, some companies even have the audacity to advertise their services as particularly privacy-friendly.

There Is Another Way

To take a stand against this widespread surveillance capitalism, which is already accepted as a necessary evil by some, we’ve joined forces with Proton, Brave, the Tor Project, and a couple of other Internet services to launch the Privacy Pledge initiative.

For one thing, the Privacy Pledge aims to show that there are indeed ways to provide online services without undermining the users’ privacy. For another thing, it proposes a set of standards every online service should adhere to in order to give users control over their data and properly protect their privacy. To learn more, please visit the Privacy Pledge website:

privacy-pledge.com →

Threema Libre: Full Independence from Google Services

After the recent introduction of Threema Push, which allows Threema to be used without Google’s push service, we now go a step further by introducing Threema Libre. By design, this Threema version for Android is completely free of proprietary dependencies, and it is available exclusively via the alternative app store F-Droid.

In Threema Libre, there’s no single line of code that would require a proprietary software library from Google or any other third party. Push notifications, for example, will only be delivered using Threema Push, and a fallback to Google’s push service is ruled out from the outset. Since Threema Libre also supports reproducible builds, it’s comparatively easy to verify that the installed app cannot leak any data to Google. And because the whole code including all components is open source, the app can be audited in its entirety.

Users of de-googled Android variants are now able to install Threema without worries via F-Droid and keep the app up to date with the store’s update management.

In order to download Threema Libre via F-Droid, it’s required to add Threema’s F-Droid repository. For details, please refer to this FAQ article.

Candid Camera: Ice Cream in Exchange for Your Data

What year were you born? What’s your phone number? And what’s your best friend’s name? – Would you answer personal questions like these in exchange for a free ice cream on a hot summer day? On Zurich’s largest square, we have put to the test how much personal information passersby are ready to disclose to get a free ice cream. The result is as funny as it is insightful:

The vast majority of the protagonists was clearly confused by the personal questions, and almost no one answered them straight off. At the same time, however, countless Internet users readily disclose the same personal information to tech companies in order to use their online services.

Yet, as the famous saying goes, if you’re not paying for a product, you are the product. This is to say that tech companies use the collected data to create detailed user profiles and generate revenue by selling targeted ads – a lucrative business because user data is much more valuable than it seems to the casual eye. Therefore, data protection and privacy comes at a price that’s worth paying for.

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Threema Push for Android

Threema Push is the new answer to the old question of how to use Threema for Android without Google’s proprietary push service. Even though the vast majority of users might not be too concerned with this question, Threema Push is a major breakthrough for users of de-googled Android variants such as /e/OS, and it allows anyone to steer clear of Google’s push service while maintaining Threema’s full functionality and usability.

By default, Google’s pre-installed (and privileged) push service is used to notify Threema for Android about incoming messages while the app is in the background. Although the notification payload is empty and no contact or message details are transferred over this channel, the so-called “push token” (a unique identifier that points to the destination app on the appropriate device) could hypothetically be used to establish a link between a given Threema user and their Google account. Therefore, it has always been possible to resort to Threema’s Polling feature instead of using Google’s push service.

With Polling enabled, Threema for Android would periodically connect to the Threema server while the app was in the background. This way, users could still receive new messages without having to open Threema. Most of the time, however, the messages would arrive with several minutes of delay, and answering calls was basically not possible unless the app was in the foreground.

Thanks to Threema Push, these inconveniences are now a thing of the past. With Threema Push, which replaces Polling, a connection to the Threema server remains open in the background, allowing new messages to arrive instantly on the phone and enabling users to answer calls no matter whether the app is open or closed. In short, privacy-conscious users no longer have to skip the “instant” part in “instant messaging.”

Find out how to activate Threema Push and learn what to consider when using it in the FAQs. More information about Threema 4.7 for Android can be found in the changelog.