PACT, or the End of CAPTCHAs: The Real Question Is Who Holds the Pass

There is a humiliation so routine by now that we barely register it: failing, as humans, the very test meant to prove that we are human. We squint at a grid of traffic lights, hesitate over a sliver of crosswalk that spills into the next square, try again, and all the while the bots we claim to be filtering sail straight through. The CAPTCHA has reached the point of absurdity where it punishes precisely the people it should be waving in. This is the backwards machinery that a project unveiled on June 22 by Cloudflare, christened PACT, finally promises to set right. Provided we pay attention to who will be standing behind the counter tomorrow.

Every CAPTCHA Leads to the Same Dead End

The market has lined them up in every conceivable form. Google’s ubiquitous reCAPTCHA, which turned us into the unpaid annotators of its datasets before quietly grading us on a behavioral score. hCaptcha, its privacy-friendly clone, which has you labeling images for the benefit of third-party algorithms. GeeTest‘s slider, hugely popular across Asia, which studies the path your mouse traces. The 3D rotation mini-games of Arkose Labs, reserved for the high-risk traffic of banks and gaming platforms. Germany’s Friendly Captcha, which swaps the puzzle for an invisible proof-of-work and a GDPR selling point. Different philosophies, one shared destination: piling friction onto the honest user in the hope that it hampers the machine more than the human.

For a few years now I have stopped playing that game, and I deploy almost nothing but Cloudflare Turnstile. The reason comes down to a single fact: it asks nothing of me. No grid, no buses to point at, just a discreet probe that interrogates the browser environment and returns a verdict without interrupting me. For the visitor, verification becomes invisible; for the site owner, integration is trivial and free. It is, to date, the best experience I have tested, and it already sketched the way out: the good CAPTCHA is the one you never see.

The Day the Machine Got Better Than Us at the Test of Being Human

If all these systems are faltering at once, it is no accident of timing but a deep shift. Language models now read a distorted image better than most of us, and resolution farms charge a few cents per thousand puzzles solved. The visual test, which assumed a human cognitive edge, rests on an edge that no longer exists. Worse still: more than half of all web traffic is now the work of bots, and the rise of autonomous agents blurs the very line the CAPTCHA claimed to draw. When your assistant books a train ticket or does your shopping while you sleep, should it be blocked as a pest or waved through as a legitimate proxy? The old binary question, human or machine, simply no longer means anything.

PACT: An Anonymous Pass

This is where PACT comes in, short for Private Access Control Tokens. The idea is elegant. A site that already has good reason to believe you are human, typically a service where you hold an account, issues an anonymous cryptographic token. Your browser keeps it and presents it elsewhere as an attestation: there is a human in the loop. Because you cleared the test once, you no longer have to start over in every corner of the web, and because the token carries no personal data, the site receiving it has no idea where it came from.

The feat lies not in the technology, which is nothing new. PACT builds on Privacy Pass, the architecture the IETF standardized in 2024 across RFCs 9576 through 9578, whose blind RSA signatures guarantee a double blindness: the issuer does not know which site you are visiting, and the site does not know who you are. Apple has been doing exactly this since 2022 with its Private Access Tokens tucked into iOS 16 and macOS Ventura, with Cloudflare as one of its production issuers. What is new in PACT comes down to two decisive extensions. The first: instead of merely attesting that “this device is a genuine iPhone,” it attests that “there is a person behind the request,” regardless of the hardware. The second: the scheme also plans to issue tokens to authorized bots, so as to tell the mandated agent apart from the feral crawler that vacuums up the web like an industrial shop-vac. And this is no solo whim of Cloudflare’s: Mozilla Firefox, Google Chrome, Microsoft Edge, and Shopify are all at the table to carry it toward an open standard. On paper, everything to like.

The Flip Side of the Token: A Two-Tier Web

Still, every pass creates, by design, two classes of citizens. On one side, traffic equipped with its tidy token, presumed trustworthy; on the other, everything else, suspect by default. And who ends up in that everything else? The Tor user, the devotee of an offbeat browser, the tinkerer whose setup is too singular for any issuer to bother signing anything for. That person, precisely because they care about their privacy, risks becoming a second-class citizen, condemned to fill in grids while everyone else glides through frictionlessly. The promise of seamlessness has a price, and it is paid by those at the margins.

On top of this sits a question of power that my editorial line cannot ignore. Cloudflare is already the bouncer for a staggering share of the internet; handing it the job of deciding who deserves a token of humanity would enshrine a single point of control over global traffic. Mozilla’s presence in the room is a precious guarantee, that of a witness committed to keeping the standard open rather than letting a few dominant players capture it, and I am sincerely glad it is there. I would temper that reassurance all the same: Mozilla draws most of its revenue from the check Google writes it, and history has shown that even the guardians of the open web know how to bend when the infrastructure demands it, as with the DRM eventually folded into Firefox. An attentive witness, then, but not a counterweight of equal heft. And a guarantee is not an architecture. It bears repeating, because the excitement makes us forget it: PACT removes the CAPTCHA, not the surveillance. Fingerprinting, your IP address, the thousand other signals your browser scatters behind it all remain intact. We strip away the visible chore and leave the invisible tracking in place.

That is why, alongside the legitimate excitement, I keep looking toward the solutions you bring back home. A proof-of-work CAPTCHA, self-hostable and open source like ALTCHA, sells neither your clicks nor your attestation to a third party, and asks no one’s permission to exist. Let us be honest: resting on proof-of-work itself, it settles the question of the legitimate AI agent no better than the others, and the human/machine line keeps slipping through its fingers too. But that is not the ground on which to judge it, because it does not promise perfect filtering; it hands the site owner control of their own door without delegating to a centralized middleman the right to say who passes. This is not the same ambition as PACT, it is a different philosophy: sovereignty rather than a pass handed down from above.

So yes, the idea behind PACT is excellent, and I would sign on with both hands to be rid of the traffic lights for good. But for now it is only a project, with no confirmed release date and no settled standards body, and the real question it raises is not technical but political. Ridding the web of the CAPTCHA is progress. Deciding who will hold the keys to the pass is another matter entirely, and it is on that ground, not the ground of cryptography, that the rest will play out.