The short version is this: In its current form, Recall takes screenshots and uses OCR to grab the information on your screen; it then writes the contents of windows plus records of different user interactions in a locally stored SQLite database to track your activity. Data is stored on a per-app basis, presumably to make it easier for Microsoft’s app-exclusion feature to work. Beaumont says “several days” of data amounted to a database around 90KB in size. In our usage, screenshots taken by Recall on a PC with a 2560×1440 screen come in at 500KB or 600KB apiece (Recall saves screenshots at your PC’s native resolution, minus the taskbar area).
Recall works locally thanks to Azure AI code that runs on your device, and it works without Internet connectivity and without a Microsoft account. Data is encrypted at rest, sort of, at least insofar as your entire drive is generally encrypted when your PC is either signed into a Microsoft account or has Bitlocker turned on. But in its current form, Beaumont says Recall has “gaps you can drive a plane through” that make it trivially easy to grab and scan through a user’s Recall database if you either (1) have local access to the machine and can log into any account (not just the account of the user whose database you’re trying to see), or (2) are using a PC infected with some kind of info-stealer virus that can quickly transfer the SQLite database to another system.
↫ Andrew Cunningham at Ars Technica
It really does seem Recall is kind of a mess in the security department, and it has a certain rushed quality about it. All the screenshots are saved in an AppData folder, and data pulled from those screenshots is stored in a local SQLite database that happens to be entirely unencrypted. TotalRecall, a tool developed by Alexander Hagenah, will neatly pull the data from Recall for you without any hassle or issues.
This truly is a security nightmare. Aside from all the obvious issues this presents, such as making it even easier for law enforcement to gain access to pretty much everything you do online, something especially troubling for minorities or in countries with less-than-stellar police departments, Recall also presents a whole host of other problems. Imagine being in an abusive relationship, and the abusive partner demanding Recall be left on at all times to exert even more control. Imagine an unscrupulous employee abusing Recall to steal sensitive information from a company for a competitor. Imagine living in some backwards part of a country with controlling religious parents, and you happen to be gay. The problems here are endless.
The fact you can turn Recall off doesn’t mean much, since in the above examples, turning it off is not an option since there are controlling people involved who will demand you keep it on. Browser history and other forms of history in your computer exist as well, of course, but they’re not always as easy to parse, they’re easier to manipulate, sanitise, and temporarily hide. Recall just combines all of this and puts a neat little bow on it, ready to be abused by anyone with bad intentions.
Recall is ill-conceived, badly implemented, and a solution looking for a problem, that in an of itself creates tons of other problems. I hope Microsoft reconsiders, but in a world where “AI” makes investors go nuts, I doubt we’ll see a sudden sense of clarity coming out of Redmond.