Chrome Kills Cookie Theft While AI Giants Hit Billion Users

Here's the part that should genuinely surprise you: even if you use two-factor authentication, a passkey, and a strong unique password, a hacker who steals the right browser cookie can walk right into your account anyway. No password needed. No 2FA prompt. Nothing. And this kind of attack has been quietly exploding for years.

Google's answer is called Device-Bound Session Credentials, or DBSCs, and it's now shipping in recent versions of Chrome for Windows and macOS. The core idea is elegant: instead of just storing a session cookie in your browser like a sticky note anyone can grab, Chrome now ties that cookie to a cryptographic key that lives inside your device's dedicated security chip — a TPM on Windows machines, a Secure Enclave on Apple devices.

To understand why this matters, you need to understand how session cookies work. When you log into your bank or your email, the server hands your browser a cookie that essentially says "this person already proved who they are." Every subsequent page load shows that cookie instead of asking you to log in again. It's convenient, but it also means that cookie is basically a skeleton key. Steal it, paste it into another browser, and you're in — same access, same permissions, no questions asked.

Attackers have known this forever, but the attack became far more attractive once the industry pushed hard on 2FA and passkeys. Those protections made traditional phishing dramatically less effective. So criminals pivoted. Infostealer malware — software designed to quietly vacuum up browser data — became a booming underground industry. Adversary-in-the-middle attacks, which intercept cookies in transit, followed the same logic. Both approaches are specifically optimized to grab session cookies, because that's now the most reliable path to account access.

DBSCs break this entire chain. When a compatible website sets a session cookie, Chrome now requires the browser to sign it using the private key stored in the security chip. The critical detail: the chip is designed so that key never leaves the hardware. An attacker who steals the cookie still can't do anything with it, because they can't produce a valid signature without the physical device it came from.

"The attacker can steal the cookie, but they can't answer a DBSC challenge," security researcher Scott Helme explained in a writeup on the feature. The stolen cookie becomes useless without the private key, and the private key isn't going anywhere.

The catch, for now, is availability. DBSCs are live in Chrome 147 on Windows and Chrome 150 on macOS, but they're only enabled for a subset of users while Google runs what appears to be a broader rollout test. Websites also need to explicitly support the standard before users get the protection, which means adoption will be gradual.

But the direction here is clearly right. Session cookie theft has been a known, serious problem for years, and most consumer-facing security advice does essentially nothing to address it. A hardware-backed fix that works invisibly in the background is exactly the kind of unglamorous security work that actually moves the needle. If Google rolls this out broadly and other browser vendors follow — which, given the open standard, they could — a whole category of account takeover attacks gets substantially harder overnight.

Consider what it took to get here. ChatGPT launched in late 2022 and was almost immediately labeled the fastest-growing software product in history. It took roughly two years to reach 500 million weekly users. It took just a few more months to approach a billion. And now, barely three years after launch, both ChatGPT and Google's Gemini are claiming one billion monthly users. That is not a small number. That is more people than use Instagram.

Google CEO Sundar Pichai announced this week that Gemini has crossed the billion monthly user mark, calling it Google's fastest-growing product ever — a statement that carries real weight given that Google also built Gmail, YouTube, and Chrome. OpenAI had quietly noted a few weeks earlier that ChatGPT crossed the same threshold, burying the milestone in a blog post about usage patterns rather than leading with the headline.

The contrast in how these announcements were made tells you something. OpenAI, which once happily touted every growth record, apparently decided underplaying a billion users was the right move. Google, trailing in the race and eager to demonstrate it's closing the gap, made it a proper moment.

Now for the part where the numbers get complicated. OpenAI reported 900 million weekly active users back in February, and reaching one billion monthly users five months later actually represents a meaningful slowdown compared to its earlier growth trajectory. Weekly and monthly figures aren't directly comparable — monthly numbers will always look bigger — so the headline symmetry of both platforms hitting "one billion" obscures some meaningful differences in momentum.

Gemini's trajectory, by contrast, looks steep. It went from 750 million monthly users in February to 950 million on Google's late-July earnings call to one billion just weeks later. That's a fast climb, and a lot of it appears to be driven by Android. Google noted that Gemini has over 100 million active users on iOS, which means the overwhelming majority of its user base is coming through Android phones where Gemini comes preinstalled. That built-in distribution advantage is something no standalone AI startup can replicate, and it's exactly why OpenAI has been investing seriously in its own hardware ambitions.

Meanwhile, Anthropic's Claude continues to grow rapidly by most external measures, but the company doesn't publish user numbers. Estimates put it well behind both giants in raw users, even as Claude Code became the tool of choice for a significant chunk of professional developers this year and forced OpenAI to accelerate its own coding product.

The broader picture is that the AI market looks a lot less like a monopoly than it did eighteen months ago. ChatGPT remains the most recognized brand in consumer AI, but brand recognition doesn't guarantee market share when your two largest competitors are Google — with a billion Android users as a captive distribution channel — and Anthropic, which has quietly become the default tool for people who use AI most seriously. The race has genuinely tightened, and nobody has pulled away.