  Using the QCD dipole picture of the hard BFKL pomeron, we derive the general
expressions of the elastic and inelastic components of the proton diffractive
structure functions. We obtain a good 7 parameter fit (including a secondary
reggeon contribution) to data taken at HERA by the H1 and ZEUS collaborations.
The main characteristic features of the model in reproducing the data are
discussed, namely the effective pomeron intercept, the scaling violations and
the beta dependence. A difference obtained in the separate H1 and ZEUS fits
leads us to analyse directly the differences between both measurements.
Predictions on R, the ratio of longitudinal to transverse photon cross sections
are performed and lead to very large values at high beta and large virtuality Q
which may lead to a discrimination between models.
