authentic as in conforming to fact and therefore worthy of belief

• "an authentic account by an eyewitness"
• "reliable information"

Synonyms

• reliableworthy of reliance or trust; worthy of being depended on; conforming to fact and therefore worthy of belief

authentic as in not counterfeit or copied

• "an authentic signature"
• "a bona fide manuscript"
• "an unquestionable antique"
• "photographs taken in a veritable bull ring"

Synonyms

• bona fideundertaken in good faith; not counterfeit or copied
• unquestionableincapable of being questioned; not counterfeit or copied; not open to question
• veritableoften used as intensifiers; not counterfeit or copied