discoverable, in a secure environment, when necessary to establish new connections. Maximum PIN length Using the minimum 4 character PIN makes it easier for a hacker to intercept. This vulnerability can be eliminated by using PINs of at least 8 characters and preferably of the maximum allowed length. Make sure no devices are using a default PIN. Security mode Use authentication and encryption (Security Mode 3) for any confidential communications. In a multiple hop link, ensure that all links in the communication chain are using the required security mode. Anti-virus software Anti-virus software can be installed on many Bluetooth and security updates devices in the same way as on a personal computer. Anti-virus software, as well as device operating software, should be kept up to date with manufacturers' revisions and security updates. Software downloads Only download or install software from trusted sources. Careful attention should be given to any security warning during software installation. Unpair from lost If a Bluetooth device is lost or stolen, it should be unpaired devices with all devices it was previously paired with, by deleting the lost device from the list of paired devices on these devices. Failure to do this will make these devices vulnerable to attack by the previously paired device. Wireless USB Security The goal of wireless USB security is to provide the same level of confidence that the user has when making a wired USB connection, namely that the devices connected are only those that the user wants to be connected and that the transmitted data is protected from unwanted external observation or modification. Chapter Eleven Table 11-7: Fixed Symmetric Key Authentication Steps Authentication step Description Device distributes its FSK This key may be either printed on the device or included to the user in the installation software. User transfers the FSK User confirms trust of the device carrying this FSK and to the host instructs the host to allow this new connection. Host confirms to device that 