Hardware DISK SECURITY
Some USB drives offer embedded hardware encryption, although these cost significantly more. Microchips within the USB drive carry out automatic transparent encryption.
Hardware systems may offer additional features, such as the ability to automatically overwrite the contents of the drive if the wrong password is entered more than a certain number of times. This type of functionality cannot be provided by a software system since the encrypted data can simply be copied from the drive. However, this form of hardware security can result in data loss if activated accidentally by legitimate users, and strong encryption algorithms essentially make such functionality redundant.
As the encryption keys used in hardware encryption are typically never stored in the computer's memory, technically hardware solutions are less subject to "cold boot" attacks than software-based systems. In reality however, "cold boot" attacks pose little (if any) threat, assuming basic, rudimentary, security precautions are taken with software-based systems[5].