Private messaging app Signal has been conducting experiments for a cryptocurrency offering for users, according to a report by the technology newsletter Platformer earlier today.

Experiments for such a token project were done on MobileCoin, a privacy cryptocurrency based on Stellar, the world’s 11th largest blockchain by market cap. Signal CEO Moxie Marlinspike served as an adviser to MobileCoin.

Signal is the flagship app of the Signal Foundation, a non-profit dedicated to open-source privacy technology. The Signal app offers end-to-end message encryption to its users — meaning any transferred data can be read only by the sender and receiver, and no other service or apps on the phone can access or decipher it.

The Signal app has surged in popularity recently. After Facebook announced changes to its WhatsApp messaging app’s privacy policy earlier this month, users abandoned WhatsApp in droves and many switched to Telegram or Signal. The number of Signal users have doubled, to 40 million, since December. The crush of new users crashed Signal last week and caused a daylong outage.

According to Platformer, Signal employees say the firm is now “actively exploring” the use of a digital currency within the platform. Such an offering could be similar to the use of electronic payments on WeChat, China’s biggest messaging app, or Facebook’s pursuit of Diem, the stablecoin project formerly named Libra.

The Platformer story expressed concerns that Signal’s exploration of cryptocurrency could be risky as it could invite more bad actors onto the platform and attract more regulatory scrutiny. 

This story originally appeared in Decrypt, a Forkast.News syndication partner, and appears here with additional updates by Forkast.News.