In Swedish common translations would be (though there are other options too):
- "authentic" -> "autentisk"
- "genuine" -> "äkta"
We don't use a translated form of Bitcoin.
To help you figure out the best word to use please provide as much detail as you can. What exactly will the hologram say in english? Will there be two separate words on it ("authentic" and "bitcoin") or is it more like a sentence "(this is an) authentic bitcoin"?
This is for physical bitcoin bills:http://printcoins.com/images/gallery/compare.jpg
The hologram will have the bitcoin logo
and floating behind it on a black background it will say original in multiple languages. The hologram is tamper evident, and under it is the private key for the bill.