is a level causing no harm in any environment nor electromagnetic interference to sensitive may occur, i.e. interference with medical devices may be neglected. Wireless locking offers best robustness against de-authentication attacks. Continuous connection based encrypted key exchange between active token and receiver dongle provides a sufficient security level prepared for certification under ISO/IEC 15408 common criteria specification. Initially connection based encrypted key exchange serves for a lower security level which appears sufficient for most requirements. Disadvantages All known approaches for wireless locking are either proprietary or just industrial standard, as e.g. ZigBee, ANT or other communication platforms, hence requiring special pairing of token and receiver/transmitter resp. Adherence to wireless air interface standards and wireless communications protocols compensates for such top level standardisation gap. Unidirectional communication between beaconing token and receiver dongle may be hacked with Man-in-the-middle attack. However, connection based challenge–response initialisation serves a much higher security level. Clear specification of battery wear is not published with all known vendors' offerings. See also Transmission concepts Bluetooth Bluetooth low energy Near Field Communication Wireless PAN Public Key Infrastructure Smart key WBAN WLAN IEEE 802.11 IEEE 802.15.1 IEEE 802.16 References Radio-frequency identification Tracking Ubiquitous computing Wireless locating