Samsung’s Personal Data Engine is a big addition to the Galaxy S25 — here’s why

Galaxy S25 Ultra Now brief
(Image credit: Tom's Guide)

Even before Samsung launched the Galaxy S25 series, it introduced the Personal Data Engine as part of the One Ui 7 software that would debut on the new flagship phones. The feature promised to deliver customized experiences while also safeguarding your privacy — a potentially winning combination.

Ideally, thanks to the Personal Data Engine on your Galaxy S25, you’ll get AI-driven searches and status updates without worrying that hackers or rogue apps might steal that data.

But how does the Personal Data Engine work — and can you trust it to keep your data safe? Let’s dive into Samsung’s technology to find out, and answer some of the burning questions you may have about this particular feature..

How Samsung’s Personal Data Engine works

Samsung Galaxy S25 review photos.

(Image credit: Future)

At its heart, the Personal Data Engine stores personalized data in a secure space, which Samsung bills as its Knox Vault. The whole thing is managed with an encryption key. This lets your phone analyze and make use of sensitive information while keeping it away from prying eyes.

Among that data you’ll find biometrics (such as your heart rate), searches, and tailored suggestions like departure times.

Crucially, Samsung is unifying content from multiple apps in a knowledge graph — effectively, a profile. Google uses a somewhat similar concept to directly answer questions in search queries rather than producing ordinary lists.

Galaxy AI can securely search your overall activity, not just individual apps. This is meant to give you a more accurate, holistic view with greater insights, even as it keeps everything in that graph private.

Samsung goes so far as to protect the engine using post-quantum cryptography. That is, it’s theoretically resistant to quantum computing hacking attempts where conventional encryption would easily collapse. This won’t be a realistic concern as full-fledged quantum computers are still years away, but it’s good to know that your protected data shouldn’t become vulnerable over the long run.

One UI 7, Samsung’s Android 15 update that underpins the Engine, helps bolster that security with Maximum Restrictions settings that limit personal data sharing in apps like Gallery and Messages, bar automatic connections to insecure Wi-Fi, and even block 2G service. There’s a dashboard to check your security status, and theft protection locks down your device if someone snatches it on the street.

You can limit app installs to authorized sources, and block USB data access while your phone is locked.

What ‘s possible with the Personal Data Engine

Now Bar scrolling between two activities

(Image credit: Tom's Guide)

The Personal Data Engine is key to some features in One UI 7, and by extension the Galaxy S25. The Now Bar, a lock screen space that provides quick access to common actions and frequently used apps, revolves around that custom info. It can help you navigate to an upcoming meeting on time, start a favorite workout, or surface apps right when you need them.

The Galaxy S25’s Now Brief feature also leans heavily on the Engine. It’s aware of how your activities and schedule mesh, and will both show relevant content as well as make timely suggestions. You might see the weather and your sleep tracking stats in the morning, a custom playlist for the evening commute, and a summary of your day as you wind down at night.

Even better, the Now Brief is supposed to become even more customized over time, as it gets to know your activities and preferences. With the Galaxy S25 shipping as recently as February, though, it’s still too early to see how this shakes out.

Natural language AI photo searches also make use of the technology, Samsung says. You’ll likewise see photo highlights from memorable days.

It’s important to note that the Now Bar and Now Brief largely rely on the knowledge graph from Samsung’s own apps. The Personal Data Engine isn’t about to tap into AccuWeather for the forecast, Apple Music for your tunes, or Notion Calendar for your itinerary. We’ve asked Samsung about app compatibility going forward, but for now you’ll have to stay within the company’s ecosystem to reap the full benefits.

Do you need Samsung’s Personal Data Engine?

Now Brief feature and Now Bar

(Image credit: Future)

The follow-up question, as you might guess, is whether or not you really need the Personal Data Engine to keep your information safe. In short: not necessarily. Depending on the app or service, your data might already be reasonably private. Many apps encrypt data and only release it under limited circumstances. Biometrics and payment info are stored in dedicated, secure chips on many phones, not just the Galaxy S25 series.

On-device AI processing is already becoming more commonplace on competing devices, for that matter. The Google Pixel 9 series processes Gemini Nano requests on the phone, and only goes to the cloud for computationally demanding AI. Apple Intelligence on iPhones uses on-device processing when possible, and a Private Cloud Compute system is designed to shield data from unwanted access (including Apple) and delete it after a given request.

As such, you don’t need to buy an S25 or even another Galaxy phone if security is your only concern.

However, that doesn’t mean Samsung is wasting its time. The Personal Data Engine is an important upgrade if you’re buying a Samsung phone and want assurances that included apps won’t expose your data to intruders or to AI models that scrape public content for training. While this doesn’t completely eliminate the possibility of identity theft or other misuses, it does minimize some of the larger risks.

The technology also helps raise the bar for AI privacy on mobile devices. Samsung joins Apple, Google, and other major manufacturers that are taking more harmonized approaches to managing your data, at least in the apps they control. You now have more choices at the store, and that should improve competition by pressuring other companies to offer equivalents to the Personal Data Engine.

In the short term, that could discourage you from switching to rival devices without such support. Still, it provides a safety net that simply didn’t exist before. It might be worth buying a Galaxy S25 or updating to One UI 7 to get AI privacy and security from an Android vendor you can trust, even if the hardware and software aren’t otherwise major draws.

More from Tom's Guide

Jon Fingas
Freelance writer

Jon is a veteran technology journalist who has written for Engadget, Android Authority, and other publications on subjects ranging from mobile to wearables — he loves emerging tech. When he's not writing, he's traveling with his family, getting fit, and indulging his passion for photography.

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