Patent ID: 8145236

Claim:
A secure localization system, comprising: user devices; at least one secure message transmitter (SMT) for transmitting secure messages (SMs) using multiple transmission power levels, the SMs comprising a set of identifiers comprising identifiers for the SMT transmitting the message and power level used for transmission, and an identifier for each SM itself; a plurality of reference points (RPs) deployed at known locations; and a localization controller configured to instruct each SMT to transmit SMs at specific power levels for receipt at the RPs, wherein each RP is configured to receive SMs and report the received SMs to the localization controller, each report containing an identifier for the RP in addition to the SM received by it, the localization controller being further configured to determine location of at least one of the user devices by comparing reports from said at least one of the user devices with the reports received from the RPs for the same set of transmitted SMs.