Data Recovery Digest

A factory reset of your phone is when you reverse it back to how it was when it, well, left the factory! This means that all of the data on your internal storage is completely wiped out. When you turn the phone back on you’ll have to go through the same setup steps that you did back when you first purchased it.

A factory reset of your phone can be performed for a number of reasons. Perhaps your phone has suffered a critical error that can’t be fixed; perhaps you’re giving the phone to a friend; perhaps you’re selling it on eBay. Whatever the reason, a factory reset can be very handy.

Company Avast carried out a test recently where they purchased 20 used Android smartphones online and tried to see whether user data could be recovered from the devices. All of these devices had been factory reset by the user selling them so that – in theory - the data should be long gone. The thing they discovered, however, is that a factory reset isn’t enough to permanently delete data.

Avast just used common data recovery tools that are available online, some of them for free. Across all the devices, Avast found over 40000 photos that had been stored on the phones previously. These pictures included those of children and of adults – the company reported of women in “various stages of undress” and many “male nude selfies”. They were also able to drag up old Google searches, emails and texts.

Overall, Avast were able to correctly identify four of the original smartphone owners using the data they discovered. It’s bad enough the original data being discovered, but to then have it attributed to you is potentially even worse.

Of course, it’s always worth taking stories like this with a little pinch of salt. Avast work in the security software business and they put out research like this to drive sales. Additionally, Google don’t claim that a factory reset is going to stop your data ever being accessed.

You might be wondering why the data can still be accessed even after a factory reset. This is because data is only ever truly deleted once it has been overwritten by new data. There’s no way of knowing what your new data is overwriting, however. As such, a full rewrite of the drive multiple times is the only way to be sure that data won’t be recovered from it.

It shouldn’t come as much surprise that Avast offer such a tool to permanently delete device data, although there are similar products like theirs on the market too.

“You'll notice that the Avast story is about 20 Android phones, not iPhones,” says Chris Bross, CTO of Drivesavers, a service that specialises in data recovery. “The recovery of data from an iPhone vs. an Android device is more challenging because of the protections that Apple puts in the security stack. Apple does a better job in their secure-wipe routine than what appears to happen with third-party apps on Android.”