Abstract: Described are a self-protecting storage device and method that can be used to monitor attempts to access protected information. Access is allowed for authorized host systems and devices while unauthorized access is prevented. Authorization use includes inserting a watermark into access commands, such as I/O requests, sent to the storage device. The access commands are verified before access is permitted. In one embodiment, block addresses in I/O requests are encrypted at the host device and decrypted at the self-protecting storage device. Decrypted block addresses are compared to an expected referencing pattern. If a sufficient match is determined, access to the stored information is provided. Self-protection can be provided to a range of storage devices including, for example, SD flash memory, USB thumb drives, computer hard drives and network storage devices. A variety of host devices can be used with the self-protecting storage devices, such as cell phones and digital cameras.