Facebook will increasingly shift its focus away from public posts to encrypted, ephemeral communications on its trio of messaging apps, CEO Mark Zuckerberg said today in a significant new blog post. In a 3,200-word missive, Zuckerberg says that encryption will be one of the keys to Facebook’s future — and that the company is willing to be banned in countries that refuse to let it operate as a result.

“As I think about the future of the internet, I believe a privacy-focused communications platform will become even more important than today’s open platforms,” Zuckerberg writes. “Today we already see that private messaging, ephemeral stories, and small groups are by far the fastest growing areas of online communication.”

“I believe the future of communication will increasingly shift to private, encrypted services”

Public social networks have their place, Zuckerberg adds, but he sees a large future opportunity built on “a simpler platform that’s focused on privacy first.” That would mark a sharp reversal for Facebook, which has grown into one of the world’s wealthiest companies by inventing exotic new methods of personal data collection and allowing brands to sell advertising against it. Facebook has spent the past two years mired in scandals around data privacy, starting with last year’s revelations around Cambridge Analytica and continuing through the biggest data breach in company history.

“I believe the future of communication will increasingly shift to private, encrypted services where people can be confident what they say to each other stays secure and their messages and content won’t stick around forever,” Zuckerberg says. “This is the future I hope we will help bring about.“

To achieve his goal, Zuckerberg says Facebook’s messaging platforms will evolve to more closely resemble WhatsApp. End-to-end encryption will become standard across Facebook’s suite of messaging apps — a feat enabled by the unification of the back-end technology that powers them, a move first reported by The New York Times earlier this year.

News of that move spurred criticism that it represented one more massive data-collection play from Facebook, which once promised European regulators that it would keep WhatsApp user data separate from its other services. Zuckerberg is now using the promise of encryption to sweeten the deal — and attempt to reverse years of reputational damage by proclaiming a near-religious belief in the power of privacy.

It could also represent a business opportunity. In his post, Zuckerberg says private, encrypted messaging tools will also create room for new business tools — especially ones around payments and commerce, the company’s current pet obsessions. The services will eventually become “a platform for many other kinds of private services,” he writes.

In addition to making messaging more private, Zuckerberg also plans to make messaging interoperable. That will start by allowing you to message between Facebook services, but Facebook eventually wants to make Instagram Direct, WhatsApp, and Messenger interoperable with SMS. (The Android version of Messenger already allows you to send and receive SMS messages.)

To achieve his privacy goals, Zuckerberg says Facebook will not “store sensitive data in countries with weak records on human rights like privacy and freedom of expression.” Countries including Russia and Vietnam are increasingly demanding that tech platforms store user data locally, where it is more easily intercepted by law enforcement agencies. The move would also seem to make less likely the possibility that Facebook will be able to open in China, one of Zuckerberg’s most cherished goals.

“Upholding this principle may mean that our services will get blocked in some countries”

“Upholding this principle may mean that our services will get blocked in some countries, or that we won’t be able to enter others anytime soon,” Zuckerberg writes. “That’s a tradeoff we’re willing to make. We do not believe storing people’s data in some countries is a secure enough foundation to build such important internet infrastructure on.”

Zuckerberg did not offer a firm time frame for achieving his vision, beyond saying it would take place “over the next few years.” He noted that building the services he described will involve many tradeoffs, and is likely to incur the wrath of law enforcement.

“We have a responsibility to work with law enforcement and to help prevent these wherever we can,” Zuckerberg writes. “We are working to improve our ability to identify and stop bad actors across our apps by detecting patterns of activity or through other means, even when we can’t see the content of the messages, and we will continue to invest in this work. But we face an inherent tradeoff because we will never find all of the potential harm we do today when our security systems can see the messages themselves.”

Facebook will also invest in making messages more ephemeral, he says. The company will consider deleting messages by default after a month or a year, allowing the user to opt out if they wish. And the company will likely let you set individual messages to expire after “a few seconds or minutes.” Moreover, Facebook will reduce the amount of time it stores metadata about messages, he says.

Of course, it’s one thing to promise a newer, more private Facebook — and another thing to deliver it. The company has a history of announcing and promoting privacy-forward features, such as anonymous login tools and a “clear history” button to reduce what advertisers know about you, and slow-rolling or canceling their actual introduction. Facebook has the worst reputation on privacy of any major tech company, and a 3,200-word blog post doesn’t do much by itself to dig the company out.

Still, Facebook has at least gone on record saying that its future will emphasize privacy in concrete ways — and that it is prepared to be blocked in many countries as a result. As more governments warm to the idea of real-time surveillance of their citizens using Facebook’s tools, it would mark a welcome shift.