@article{PDM_2010_4_a1,
     author = {P. A. Pautov},
     title = {Authentication in multi-tier systems using proxy signatures},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {18--22},
     publisher = {mathdoc},
     number = {4},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2010_4_a1/}
}