Both texts are equally authentic.

两种文本具有同等效力。

《新英汉大辞典》

This contract is made out in Chinese and English, both versions being equally authentic.

本合同以中文及英文两种文字书就，两种文字的条款具有同等效力。

youdao

This Treaty shall be signed in a single original in the English, Arabic, Chinese, French, Russian and Spanish languages, all texts being equally authentic.

本条约签字原件应为一份，其英文、阿拉伯文、中文、法文、俄文和西班牙文各文本具有同等效力。

youdao

In its seven seasons, Bourdain has traveled to almost every corner of the globe in search of authentic cuisine, and equally-authentic cultural experiences.

FORBES: Bad Boys Die Early, Curmudgeons Get to Age

These days, authentic stone basins are scarcer than bustles, so trough- planting zealots have taken to making their own equally porous (and much lighter) containers out of hypertufa a mixture of portland cement, peat moss, perlite and fibermesh.

WSJ: Trough Gardening: A Challenger to the Terrarium Craze?