Secure messaging app developer Signal says its US operation hangs in the balance due to a proposed law in America.

In a blog post on Thursday, the non-profit said it will have to shut down it stateside presence should the EARN IT Act be passed and signed into law. Legal and liability concerns would make it impossible to operate in the US, it claims. However, that isn't to say Signal would close down entirely, or not offer a service in America, just that its operations in the country would need to move elsewhere.

"Some large tech behemoths could hypothetically shoulder the enormous financial burden of handling hundreds of new lawsuits if they suddenly became responsible for the random things their users say, but it would not be possible for a small nonprofit like Signal to continue to operate within the United States," Signal's Joshua Lund said.

"Tech companies and organizations may be forced to relocate, and new startups may choose to begin in other countries instead."

Pitched as a measure to stop the spread of child sex abuse imagery online, the EARN IT Act proposes stripping websites and the like of their Section 230 free-speech exemption under the 1996 Communications Decency Act. This would leave them open to lawsuits should they fail to adhere to a number of yet-to-be-determined best practices, the most likely being either allowing law enforcement the ability to decrypt select conversations or requiring providers to screen all messages.

This is the rub for Signal and digital rights groups who oppose the bill. They believe that it will be impossible to be able to screen all messages on the service without compromising the security of the entire platform. After all, secure end-to-end encryption means exactly that: conversations are protected at all steps between the sender and recipient, and not even Signal can access the contents.

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"You can’t have an Internet where messages are screened en masse, and also have end-to-end encryption any more than you can create backdoors that can only be used by the good guys. The two are mutually exclusive," argued Joe Mullin at the Electronic Frontier Foundation, another opponent of the bill.

"Concepts like 'client-side scanning' aren’t a clever route around this; such scanning is just another way to break end-to-end encryption. Either the message remains private to everyone but its' recipients, or it’s available to others."

Signal notes that, in its case, use of end-to-end encryption is the fundamental draw of the platform, and its benefits are widely recognized by some of the same people who want to torpedo the Section 230 protections.

"For a political body that devotes a lot of attention to national security, the implicit threat of revoking Section 230 protection from organizations that implement end-to-end encryption is both troubling and confusing," Lund said.

"Signal is recommended by the United States military. It is routinely used by senators and their staff. American allies in the EU Commission are Signal users too. End-to-end encryption is fundamental to the safety, security, and privacy of conversations worldwide."

Meanwhile, the EARN IT Act remains in its early phases, having yet to see any vote in the House or Senate. ®