‘Delete’ does not wipe out data

Research has shown that less than 40 per cent of memory cards sold through second-hand auction sites such as eBay and Gumtree have been adequately wiped to stop personal information from being recovered.

Memory cards in mobile phones and tablet computers can often contain SMS conversations, photographs, resumes, banking and legal documents, not to mention user names and passwords for online services.

In some instances, memory cards have to be handed over to the police for further investigation of suspected illegal content.

To complicate matters further, we are increasingly using our own mobile devices to access important data at work.

This confidential data may leave the organisation via our electronic device and we may subsequently sell the device or its memory card when it is no longer required.

Specialised computer forensic software can be used to extract the confidential data from memory cards.

However, in many cases the extraction process is simple because no genuine attempt to remove data permanently was made.

In many instances, second-hand memory cards are bought for only a few dollars yet the value of the data contained is often significantly more.

People can misinterpret the function of ‘delete’ or ‘format’ as an action that permanently removes data. Unfortunately, this is not entirely accurate, and data that has been deleted or formatted can still be recovered.

Software that removes data permanently is available. It overwrites existing data with 1s or 0s. When selecting a tool, it is best to use one that meets a government security standard.

If you are not willing to go to the effort of using software tools, physically destroying the memory card with a hammer is the next safest option.

Therefore, we should ask ourselves are we willing to risk being the next victim of cyber crime by selling our data for only a few dollars on second-hand auction sites.