Peter Gutmann

Security

Generally considered to be the most secure named algorithm, the Peter Gutmann method involves overwriting data on the storage device 35 times. This results in very high security, meaning that even highly capable data recovery professionals may not be able to recover even the slightest piece of previous data.

Time

As with all software erasure methods, there must be a compromise between security and speed. Therefore due to the high security invloved in the Peter Gutmann method, it can take an extremely long time to erase data. For instance, to erase a modern hard drive would probably take over 24 hours. Time also varies depending on factors such as device speed.