Machine shredding is the process of using a shredding machine to physically destroy the media and make the data unrecoverable. This is more effective than software formatting, which only erases the data logically and may leave traces that can be recovered by special tools1. Encrypting and destroying keys may prevent unauthorized access to the data, but it does not erase the data from the media. Wiping and rewriting three times is unnecessary and may reduce the lifespan of the media, especially for solid state drives2. Machine shredding is also recommended by various security standards and guidelines for media disposal345.