Methods and apparatus for converting original data into a plurality of sub-bands using wavelet decomposition; encrypting at least one of the sub-bands using a key to produce encrypted sub-band data; and transmitting the encrypted sub-band data to a recipient separately from the other sub-bands....http://www.google.fr/patents/US7864959?utm_source=gb-gplus-shareBrevet US7864959 - Methods and apparatus for multi-level dynamic security system
Methods and apparatus for multi-level dynamic security system
