Related News

Personal Computing

Remove Data before Recycling or Disposing Handheld Devices

by by Joe Chow
 
Handheld devices such as smart phones and tablets are so popular nowadays that their daily use frequently touch on sensitive and personal data such as email messages, conversational records, contacts, calendar events and even bank transactions. Many people replace their old devices but do not know how to prevent the stored data from exposure to people who should not have it. In this article, we shall discuss ways to clean up the data inside some common handheld devices to make them safe for recycle use or disposal.
 
Physically Destroy the Device?
 
Yes, it is possible to use this method to render the data in a handheld device unrecoverable. To physically destroy a device, some heavy destruction tools can be employed to mechanically cut or shred a device into very small fragments. Depending on the machinery used, devices can be shredded into tiny pieces such that no one can distinguish even the original shape of the devices. This effectively will “destroy” the data inside, but this also destroy the device altogether. If you plan to recycle the device for other use, other data erasing methods for handheld devices should be employed instead.
 
Use “Factory Reset” to Remove Data
 
Alternatively, you can choose data erasing methods to safely remove the data without destroying the device. This is usually done by performing a “factory reset” on the device. A “factory reset” deletes all data/files/programs stored in a device and erases all user identity/options/preferences, then restores the device to its initial state. Please follow the links below to learn how to perform a “factory reset” on some commonly used devices: 
For iOS, please refer to:
 
For Android, please refer to:
 
For Windows, please refer to:
 
Due to the diversity of Android and Windows devices, please refer to the respective manufacturer of your device’s brand/model.  
To increase the effectiveness of data removal via a “factory reset”, it is advised that you encrypt the device before resetting it. Encryption is by default turned on in some brands of device, however, some will require you to explicitly turn it on. The option to turn encryption on/off is available on most devices and is usually found within the Settings menu.
 
In most cases, encryption followed by a “factory reset” is usually good enough for secure data removal. However, if you want to do more so as to make it even harder for anyone else to retrieve data from your discarded device, you may consider using a device wiping method. A common way to wipe data in a device is to refill the memory/storage with dummy data whereby ensuring any trace of data that might be left after a “factory reset” be totally overwritten. The time required for wiping will depend on the size of the internal memory/storage of the device, e.g. a 128GB iPhone may take over 2 hours. Device wiping (with different dummy content each time, if desired) can be performed as many times as you wish. Please note that device wiping involve complex procedures and may not be necessary for average users.
 
Require Assistance?
 
For devices owned by the University, the Computing Services Centre (CSC) can offer advice on the “factory reset” and the wiping of devices. Due to data security reason, this has to be performed by the device owner with on-site assistance by a CSC staff. Due to the diversity of device brand/model, the CSC can only provide support to our best efforts.
 
In addition, there are also outside service providers which can provide professional data removal services. They are able to offer a list of data removal services for many different types of handheld devices. If you decide to use their service, please do not initiate any work until you have totally understood the underlying terms and conditions so as to prevent any unnecessary argument in the future. The CSC will try its best to provide some advice and please feel free to contact us via our Help Desk.