Secure inductively-coupled communications systems

摘要

Security in inductively coupled communications systems, such as near field communications (NFC), may be improved by restricting signals carrying user data to an authorized data transmission region. Security may be particularly important when the NFC carries financial transaction information or authorization credentials. Scramble signals may be transmitted along with data signals carrying the user data and designed to overshadow the data signals outside of the authorized data transmission region. The scramble signal transceiver may be designed to have a slower decay rate with distance from the transceiver than the data signal. By adjusting the power levels of the scramble signal and the data signal, the authorized data transmission region may be adjusted. Scramble signals may not be required if the data signal strength outside the authorized data transmission region is below the minimum threshold value required by eavesdropping receivers.

主权项

1. A method, comprising:
transmitting a data signal with a data field distribution having a first decay rate, in which the data signal carries user data; transmitting one or more scramble signals with one or more scramble field distributions corresponding to the one or more scramble signals having a second decay rate different from the first decay rate, in which the scramble signal does not carry user data; and adjusting the data field distribution and the scramble field distributions such that one or more of the scramble signals overshadow the data signal in all but selected regions.