IrisCode is a digitized, normalized, compact encoding of the unique texture visible in the iris of an eye, for purposes of automated biometric identification. The IrisCode is mapped between the inner and outer boundaries of the iris, so it is size-invariant, distance-invariant, and also invariant to changes in pupil dilation. This intrinsic normalization facilitates the searching and matching operations. In the standard format (called “iris2pi”) used in public deployments of iris recognition, the IrisCode is based on a phase encoding by Gabor wavelets, and it also incorporates masking bits signifying the detection of eyelids, eyelashes, reflections, or other noise. Standard code lengths are 512 or 1,024 bytes. The IrisCode enables simple parallel logical operators XOR (Exclusive-OR) and AND to generate Hamming Distance scores for similarity between IrisCodes, at speeds of typically 1 million complete IrisCode comparisons per second.