How to securely erase data

Erasing data for good is more dif­fi­cult than you would think, because there are var­ious ways to delete and erase! The neces­sity of erasing data securely is how­ever demon­strated yet again by a cur­rent case which occurred in the canton of Zurich.

As reported by var­ious media, IT devices were not cor­rectly dis­posed of in the canton of Zurich. That’s how it was pos­sible to retrieve con­fi­den­tial data from sev­eral hard drives, ending up with var­ious people involved in the Zurich sex and drug scene.

This case demon­strates just how impor­tant it is to delete sen­si­tive data – which is not so dif­fi­cult at all: Data can be irrev­o­cably oblit­er­ated by phys­i­cally destroying data car­riers. A more work­able alter­na­tive though is “dele­tion by over­writing” using spe­cial soft­ware. These over­write the areas on a data car­rier con­taining data to be deleted with (random) data pat­terns – usu­ally sev­eral times. This process will erase data irretrievably.

You can find out how you can securely erase data car­riers such as hard drives, USB sticks or SD cards and smart­phones or tablets and learn about the alter­na­tives avail­able (encryp­tion) here.