YubiKey is a small security device manufactured by the company Yubico. It is used to give online accounts additional protection against unauthorized access by requiring the user to use the YubiKey every time he or she logs in or initiates an action on his or her account such as withdrawing funds.
Once you enable the 2FA security feature via YubiKey on your PDAX account, you will be asked to use your YubiKey before you can proceed with logging in or withdrawing cryptocurrency from your wallet every time you perform these steps.
Please note that PDAX urges all users to enable 2FA (via OTP or YubiKey) to avoid delays when withdrawing cryptocurrencies from their PDAX accounts. If 2FA is not enabled, all cryptocurrency withdrawal requests have to be manually approved for security reasons. This can lead to longer processing time especially if the request is made over the weekend or during the holidays.