Patent ID: 8588406

Claim:
A semiconductor integrated circuit comprising: a mask generator configured to generate a mask for obfuscating input data, the mask generator including: an attribute memory configured to store an attribute value associated with the input data as an attribute bitfield; a plurality of primary randomizing units, each primary randomizing unit arranged to receive a subset of bits of the attribute bitfield as an input, and to output a bitfield as a function of the input; a plurality of secondary randomizing units, at least one of the secondary randomizing units arranged to receive an input derived from the output of at least two of the primary randomizing units, and arranged to output a bitfield as a function of the input of the at least one of the secondary randomizing units; and a mask deriving unit arranged to derive the mask from the output of the at least one of the secondary randomizing units; a mask memory configured to store the mask; and a masking unit configured to receive the input data at a first input, to receive the mask at a second input, and to obfuscate the input data by combining bits of the input data with bits of the mask.