A drawback to the small size of flash drives is that they are easily misplaced or otherwise lost. This is a particular problem if they contain sensitive data (see data security). As a consequence, some manufacturers have added encryption hardware to their drives, although software encryption systems which can be used in conjunction with any mass storage medium will achieve the same result. Most drives can be attached to keychains or lanyards. The USB plug is usually retractable or fitted with a removable protective cap.
M-Systems, an Israeli company, were granted a US patent on November 14, 2000, titled "Architecture for a [USB]-based Flash Disk", and crediting the invention to Amir Ban, Dov Moran and Oron Ogdan, all M-Systems employees at the time. The patent application was filed by M-Systems in April 1999.[6][1][7] Later in 1999, IBM filed an invention disclosure by one of its employees.[1] Flash drives were sold initially by Trek 2000 International, a company in Singapore, which began selling in early 2000. IBM became the first to sell USB flash drives in the United States in 2000.[1] The initial storage capacity of a flash drive was 8 MB.[7] Another version of the flash drive, described as a pen drive, was also developed. Pua Khein-Seng from Malaysia has been credited with this invention.[8] Patent disputes have arisen over the years, with competing companies including Singaporean company Trek Technology and Chinese company Netac Technology, attempting to enforce their patents.[9] Trek won a suit in Singapore,[10][11] but has lost battles in other countries.[12] Netac Technology has brought lawsuits against PNY Technologies,[13] Lenovo,[14] aigo,[15] Sony,[16][17][18] and Taiwan's Acer and Tai Guen Enterprise Co.[18]
Some manufacturers deploy physical authentication tokens in the form of a flash drive. These are used to control access to a sensitive system by containing encryption keys or, more commonly, communicating with security software on the target machine. The system is designed so the target machine will not operate except when the flash drive device is plugged into it. Some of these "PC lock" devices also function as normal flash drives when plugged into other machines.
The 32GB capacity of this SanDisk Ultra SDCZ48-032G-A46 flash drive provides ample room to store photos, music, videos and other files. The USB 3.0 interface and up to 80MB/sec. read speed make it easy to transfer files to and from your computer. (Ten times faster than USB 2.0 drives. Write speeds up to 10 times faster than Cruzer USB 2.0 drive.)* *USB 3.0 port required. Based on internal testing; performance may be lower depending upon host device.
_{Inside the plastic casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs).[citation needed] Typically, one of these ICs provides an interface between the USB connector and the onboard memory, while the other is the flash memory. Drives typically use the USB mass storage device class to communicate with the host.[28]}
A USB flash drive[note 1] is a data storage device that includes flash memory with an integrated USB interface. It is typically removable, rewritable and much smaller than an optical disc. Most weigh less than 30 g (1 oz). Since first appearing on the market in late 2000, as with virtually all other computer memory devices, storage capacities have risen while prices have dropped. As of March 2016, flash drives with anywhere from 8 to 256 GB were frequently sold, while 512 GB and 1 TB units were less frequent.[2][3] As of 2018, 2 TB flash drives were the largest available in terms of storage capacity.[4] Some allow up to 100,000 write/erase cycles, depending on the exact type of memory chip used, and are thought to last between 10 and 100 years under normal circumstances (shelf storage time[5]).

The various writable and re-writable forms of CD and DVD are portable storage media supported by the vast majority of computers as of 2008. CD-R, DVD-R, and DVD+R can be written to only once, RW varieties up to about 1,000 erase/write cycles, while modern NAND-based flash drives often last for 500,000 or more erase/write cycles. DVD-RAM discs are the most suitable optical discs for data storage involving much rewriting.

Also, HP has introduced a USB floppy drive key, which is an ordinary USB flash drive with additional possilibility for performing floppy drive emulation, allowing its usage for updating system firmware where direct usage of USB flash drives is not supported. Desired mode of operation (either regular USB mass storage device or of floppy drive emulation) is made selectable by a sliding switch on the device's housing.[51][52]
Some organizations forbid the use of flash drives, and some computers are configured to disable the mounting of USB mass storage devices by users other than administrators; others use third-party software to control USB usage. The use of software allows the administrator to not only provide a USB lock but also control the use of CD-RW, SD cards and other memory devices. This enables companies with policies forbidding the use of USB flash drives in the workplace to enforce these policies. In a lower-tech security solution, some organizations disconnect USB ports inside the computer or fill the USB sockets with epoxy.
The New York-based Human Rights Foundation collaborated with Forum 280 and USB Memory Direct to launch the "Flash Drives for Freedom" program.[80][81] The program was created in 2016 to smuggle flash drives with American and South Korean movies and television shows, as well as a copy of the Korean Wikipedia, into North Korea to spread pro-Western sentiment.[82][83]
The U3 company works with drive makers (parent company SanDisk as well as others) to deliver custom versions of applications designed for Microsoft Windows from a special flash drive; U3-compatible devices are designed to autoload a menu when plugged into a computer running Windows. Applications must be modified for the U3 platform not to leave any data on the host machine. U3 also provides a software framework for independent software vendors interested in their platform.
As highly portable media, USB flash drives are easily lost or stolen. All USB flash drives can have their contents encrypted using third-party disk encryption software, which can often be run directly from the USB drive without installation (for example, FreeOTFE), although some, such as BitLocker, require the user to have administrative rights on every computer it is run on.
The New York-based Human Rights Foundation collaborated with Forum 280 and USB Memory Direct to launch the "Flash Drives for Freedom" program.[80][81] The program was created in 2016 to smuggle flash drives with American and South Korean movies and television shows, as well as a copy of the Korean Wikipedia, into North Korea to spread pro-Western sentiment.[82][83]
USB flash drives are only limited by the cost of the storage space and the physical constraints of the drive. Some of the cheaper flash drives can store less than a gigabyte, but modern high-end flash drives can store as much as 1TB of data, about equivalent to a typical hard drive. A standard external USB drive can store or backup around 64GB, 128GB, 256GB, or 512GB of data. As storage space increases, USB flash drives have become proficient at storing massive files such as ultra high-definition videos that display at 4K or even 8K resolution.

A minority of flash drives support biometric fingerprinting to confirm the user's identity. As of mid-2005,[needs update] this was an expensive alternative to standard password protection offered on many new USB flash storage devices. Most fingerprint scanning drives rely upon the host operating system to validate the fingerprint via a software driver, often restricting the drive to Microsoft Windows computers. However, there are USB drives with fingerprint scanners which use controllers that allow access to protected data without any authentication.[70]

You are eligible for a full refund if no ShippingPass-eligible orders have been placed. You cannot receive a refund if you have placed a ShippingPass-eligible order. In this case, the Customer Care team will remove your account from auto-renewal to ensure you are not charged for an additional year and you can continue to use the subscription until the end of your subscription term.