Created attachment 108065 [details]
Sorry, we don't do certification. Besides, what could we certify about you? We can't certify the quality of your Hungarian translations. You can point people to your translations on www.g.o and let them judge for themselves. You can point them to http://www.gentoo.org/doc/hu/overview.xml where you are named.
If you started working on the GDP quiz to be recruited, you'd get an @gentoo.org email and an official Gentoo translator status. Would that qualify as certification?
If you need something more official, you might want to look at lpi.org
Not gentoo-specific, not cheap, but affordable. They often offer discounts on their tests on Linux/FLOSS fairs like fosdem, linux world...
FYI, we all do Gentoo stuff in our spare time and only very few lucky ones have managed to involve Gentoo in one way or another in their professional life.