  We introduce a new fixed-length representation of fingerprint minutiae, for
use in template protection. It is similar to the `spectral minutiae'
representation of Xu et al. but is based on coordinate differences between
pairs of minutiae. Our technique has the advantage that it does not discard the
phase information of the spectral functions. We show that the fingerprint
matching performance (Equal Error Rate) is comparable to that of the original
spectral minutiae representation, while the speed is improved.
