Bio-hexacrypt, or biohexacrypt code, was an incredibly secure form of code encryption, developed by Kupohans.
Used during the New Republic era and most prominently by the First Order, bio-hexacrypt was used to secure valuable data, such as data networks and clearance codes. Notably, the Supremacys clearance codes were bio-hexaencrypted, and re-scrambled every hour; leading Finn and Rose Tico to seek out the Master Codebreaker to gain access.
DJ was capable of handcrafting custom computer spikes and bypass keys capable of befuddling bio-hexacryption, albeit only temporarily.
The Master Codebreaker kept his real identity a secret, but posted his personal data on a public access node wrapped in a quantum-spread bio-hexacrypt code. Anyone capable of cracking the code was welcome to claim his title of Master Codebreaker; though, as of the Mission to Canto Bight, no one had even come close.