  An accreting supermassive blackhole, the central engine of active galactic
nucleus (AGN), is capable of exciting extreme amplitude Alfven waves whose
wavelength (wave packet) size is characterized by its clumpiness. The
pondermotive force and wakefield are driven by these Alfven waves propagating
in the AGN (blazar) jet and accelerate protons/nuclei to extreme energies
beyond Zetta-electron volt (ZeV$=10^{21}$ eV). Such acceleration is prompt,
localized, and does not suffer from the multiple scattering/bending enveloped
in the Fermi acceleration that causes excessive synchrotron radiation loss
beyond $10^{19}$ eV. The production rate of ZeV cosmic rays is found to be
consistent with the observed gamma-ray luminosity function of blazars and their
time variabilities.
