In the summer of 2006, Fidel Castro unexpectedly announced that he was temporarily handing over power to his brother. Turns out he needed to undergo intestinal surgery. Afterward, an anchor on state-run television read a statement, said to have been written by Castro, attesting that all was well. But there were no photographs of Fidel in recovery, no nine-hour radio address from his hospital bed. Rumors flew that the longtime Cuban leader had died. Then, about two weeks after the operation, the Cuban regime released a picture of the bearded leader wearing an Adidas jacket and holding the August 12, 2006, edition of the Cuban Communist Party newspaper, Granma. He was alive, at least as of that date. Fidel Castro had been verified.

The Cuban regime was onto something. The people hadn’t believed statements that Castro was alive and well—so it found a way to offer hard-to-deny proof.

Today we are like the Cubans, circa 2006. In our case, fakery is gushing in from everywhere and we’re drowning in it. “Deepfake” videos mash up one person’s body with someone else’s face. Easy-to-use software can generate audio or video of a person saying things they never actually uttered. Even easier? Fake clicks, fake social media followers, fake statistics, fake reviews. A gaggle of bots can create the impression that there’s a lot of interest in a topic, to sway public opinion or to drive purchases.

It is even a breeze to create a fake newspaper online. On November 5, 2016, Jestin Coler, founder of the fake newspaper Denver Guardian, posted a “news story” saying an FBI agent involved in leaking Hillary Clinton’s emails was found dead in an “apparent murder-suicide.” “Everything about it was fictional: the town, the people, the sheriff, the FBI guy,” Coler told NPR. “Our social media guys kind of go out and do a little dropping it throughout Trump groups and Trump forums, and boy, it spread like wildfire.” The made-up tale went viral on Facebook before the 2016 election—and was probably seen by tens of millions. “It was so easy,” Coler told me once.

We’ve lost signals of credibility. Before the online era, you would need to shell out a lot of money to print a fake newspaper, or it would look like an obvious counterfeit. (In fact, in January a group called the Yes Men printed 25,000 copies of a parody Washington Post with anti-Trump fare; that stunt cost more than $30,000, according to one of the organizers, who was interviewed in the real Washington Post.) Scrolling through Facebook, however, there’s little distinguishing an article from The Wall Street Journal from the sham Denver Guardian. It’s easier than ever to be fooled.

Which brings me back to the picture of Castro with the newspaper. It was a crude but effective verification mechanism. We need to find digital equivalents, especially to verify the time and place of documents, photographs, and videos, as well as to authenticate individual identities. This is a daunting task that will mean developing hardware, software, and protocols, not to mention institutions to oversee the process.

How would this work? It’s harder than just showing the people an image of a print newspaper (if you can find one), because digital bits can easily be altered. But it is possible to develop schemes to approximate this. For example, the digital front page of The New York Times on the date and time a photograph was taken could be used to generate keys to “digitally sign” any photograph and its metadata. That’s a bit like making the photograph hold a copy of that moment’s New York Times, so to speak, except the “holding the paper” part is done by cryptographic digital signing. This is a simplification, and there would be many details to work out: a camera with specialized hardware, a spoof-resistant method of geolocation, a means to add a “taken before” verification (using existing methods such as trusted time stamps), and such. Blockchain databases—hyped for so much else—could actually be useful for verification.