On Sunday, Block CEO and Twitter co-founder Jack Dorsey launched an open source chat app called Bitchat, promising to deliver “secure” and “private” messaging without a centralized infrastructure.

The app relies on Bluetooth and end-to-end encryption, unlike traditional messaging apps that rely on the internet. By being decentralized, Bitchat has potential for being a secure app in high-risk environments where the internet is monitored or inaccessible. According to Dorsey’s white paper detailing the app’s protocols and privacy mechanisms, Bitchat’s system design “prioritizes” security.

But the claims that the app is secure, however, are already facing scrutiny by security researchers, given that the app and its code have not been reviewed or tested for security issues at all — by Dorsey’s own admission.