Twitter co-founder launches offline messaging app

Bitchat — the new messenger from Twitter and Block founder Jack Dorsey — is now available for download in the iOS App Store. The app works over Bluetooth networks without cellular or Wi-Fi, but it's already drawing security concerns.

TechCrunch writes about it.

What Bitchat can do and why there are comments about it

Dorsey said he coded the basic version of the app in a single weekend in early July. Bitchat uses Bluetooth mesh, allowing users to send messages to anyone within Bluetooth range (usually about 100 meters), even without network or Wi-Fi coverage.

The interface is intentionally minimalist. There's no login system: upon launch, an instant messaging window opens immediately, showing posts from people nearby (if any), and the display name can be set and changed at any time.

The demand for such apps is not new: Bluetooth messengers are often useful at large festivals with congested connections or after natural disasters when the internet is down.

At the beta launch this month, Dorsey pitched Bitchat as a secure and private platform. However, security researcher Alex Radochea noted in a blog post that it's easy to impersonate someone else on Bitchat, which casts doubt on the claimed level of security.

"In cryptography, details matter. A protocol that has the right vibes can have fundamental substance flaws that compromise everything it claims to protect," he noted.

Dorsey later admitted that the program has not yet been externally audited for security, so it may still have vulnerabilities.

The problem with spoofing also affects app stores. Bitchat is currently available for iOS via the App Store, and on Android, it can be installed from the GitHub page. At the same time, several applications that pretend to be Bitchat have appeared on Google Play, and they have already collected thousands of downloads. Dorsey did not comment directly on this, but he shared another user's post on X with a warning that Bitchat is not yet on Google Play and that you should "beware of fakes."

As a reminder, the Signal messenger is deservedly considered one of the most secure — it encrypts not only messages, but also calls. However, even the best technologies do not guarantee complete security without the correct user settings.