Abstract: Digital certificates are signed by a server's private key and installed at lock controllers that restrict access to physical resources. The server's public key is distributed to lock controllers and to wireless mobile devices operated by users who are given access to primary locks which secure access to physical resources, and secondary locks, which retain the primary locks within operable vicinity to the physical resources. Additionally, tertiary locks may secure access to internal components of the primary or secondary locks. When a wireless mobile device enters the vicinity of a lock controller, the digital certificate of the lock controller is used as the basis for encrypted communications between the wireless mobile device and the lock controller. Wireless mobile devices may be used to gather evidence of integrity of the locks after use. Lock controllers may be powered by energy harvesting devices.

Abstract: Digital certificates are signed by a server's private key and installed at lock controllers that restrict access to physical resources. The server's public key is distributed to lock controllers and to wireless mobile devices operated by users who are given access to primary locks which secure access to physical resources, and secondary locks, which retain the primary locks within operable vicinity to the physical resources. Additionally, tertiary locks may secure access to internal components of the primary or secondary locks. When a wireless mobile device enters the vicinity of a lock controller, the digital certificate of the lock controller is used as the basis for encrypted communications between the wireless mobile device and the lock controller. Wireless mobile devices may be used to gather evidence of integrity of the locks after use. Lock controllers may be powered by energy harvesting devices.

Abstract: Digital certificates are signed by a server's private key and installed at lock controllers that restrict access to physical resources. The server's public key is distributed to lock controllers and to wireless mobile devices operated by users who are given access to primary locks which secure access to physical resources, and secondary locks, which retain the primary locks within operable vicinity to the physical resources. Additionally, tertiary locks may secure access to internal components of the primary or secondary locks. When a wireless mobile device enters the vicinity of a lock controller, the digital certificate of the lock controller is used as the basis for encrypted communications between the wireless mobile device and the lock controller. Wireless mobile devices may be used to gather evidence of integrity of the locks after use. Lock controllers may be powered by energy harvesting devices.

Abstract: Digital certificates are signed by a server's private key and installed at lock controllers that restrict access to physical resources. The server's public key is distributed to lock controllers and to wireless mobile devices operated by users who are given access to primary locks which secure access to physical resources, and secondary locks, which retain the primary locks within operable vicinity to the physical resources. Additionally, tertiary locks may secure access to internal components of the primary or secondary locks. When a wireless mobile device enters the vicinity of a lock controller, the digital certificate of the lock controller is used as the basis for encrypted communications between the wireless mobile device and the lock controller. Wireless mobile devices may be used to gather evidence of integrity of the locks after use. Lock controllers may be powered by energy harvesting devices.

Abstract: A system and method of improving signal intelligibility over an interference signal is provided. The system includes a psychoacoustic professor having a psychoacoustic model wherein the level of a signal-of-interest is improved so as to be audible above noise and so as not to exceed a predetermined maximum output level. The system can be combined with active noise cancellation.

Abstract: A sound intelligibility enhancement (SIE) system is disclosed. The SIE system uses a psychoacoustic model and preferably an oversampled filterbank wherein the level of a signal-of-interest that falls below the environmental noise is selectively amplified as a function of the input level and frequency so that it is audible above the noise but never exceeds a predetermined maximum output level as a function of frequency. The SIE system can be combined with active noise cancellation.