6 Feb 2014

How to keep your data safe when you sell an old phone

Restoring your phone to factory settings does not always get rid of your data, Channel 4 News can reveal. So how can you keep your personal information safe when you sell on your old phone?

Video: SensePost’s Glenn Wilkinson tells Reporter Sarah Smith how data can be protected

A Channel 4 News Data Baby investigation has revealed that two of the UK’s largest pawn shop chains are selling second-hand phones which still contain swathes of deeply personal information from their previous owners.

Cash Converters said that all phones are wiped “to a standard level” by restoring them to factory settings. But Channel 4 News found that this does not permanently delete old data, and it can still be retrieved using specialist software.

If you’re worried about other people getting hold of any data that may be stored on your old phone, there are a few options you can use to keep it secure when you pass it on for someone else to use.

If you want to sell your phone to a second-hand shop you could consider overwriting your data using specialist software, the Information Commissioners Office (ICO) advises.

“You might want to consider using specialist deletion software, either by installing the software on your desktop or laptop computer and connecting the phone via USB, or by installing an app from a trusted developer and downloaded from a trusted app store,” said the ICO.

There are various options available that work on different devices and this will ensure that your data can’t be accessed – even after a factory reset.

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Encrypting your data

Security experts also advise encrypting your data, twice, so it can’t be accessed after an old phone has been passed on to be used by someone else, or even if it is lost or stolen.

An iPhone 4S device, or a newer Apple model, will encrypt data automatically. With android phones, the default behaviour is the opposite, said Mr Wilkinson – but you can change the settings on your device to enable data encryption. It might run slightly slower, he adds, but it will protect your data.

It is still difficult to retrieve data from older iPhones, but to be absolutely sure, apps can be downloaded from the Apple store, to overwrite the phone’s free space and securely remove the data.

Of course security should start long before you get rid of a phone. The National Mobile Phone Crime Unit recommends using a pincode lock to deter thieves from accessing your phone as soon as you get it.

Read more advice from the ICO on mobile phone security here.

SensePost experts will be taking part in a live Twitter Q&A from 7pm – follow @DataBabyC4 or #datababy to take part