The decryption challenge Fortbyte #17 is located far north of the map, in the hot springs in the middle of the jungle. Head to the pond where there is a wooden fish building, and you will find the chip in the fish tail.
Written by Augustin "TheGreatReview" Héliot. Translated from French by Millenium.us.org.
The challenges and Fortbyte locations of the Fortnite Season 9 decryption challenge, as well as the complete list of Fortbytes, are to be found in this article.
