Decrypted Data will be an important resource for all Guardians in Destiny 2 Season of the Splicer. It can be used to unlocked new upgrades for your Splicer Gauntlet, or you can use it to focus Umbral Engrams in the Prismatic Recaster. It is this last usage that is giving players the idea that they can farm the resource somewhere, and they are correct.
The first place that players can get Decrypted Data is by completing the weekly seasonal challenges. Just like the previous season, different seasonal challenges give different rewards, and some of them will give Decrypted Data, usual large amounts of it. By complete these challenges this season, players will earn a reasonable amount of the resource overall.
The second source is through the Season Pass. At Ranks 2, 12, and 32, layers will get one-time rewards of Decrypted Data. This will take a while, depending on how much the player plays the game. The third and final method is the most interesting one, for those looking to farm the resource for Engrams.
By completing an Override activity, and using a Key Code to open a Conflux Chest, players will have a chance to get some Decrypted Data. It is not guaranteed, and the amount can vary, so prepare to do a lot of farming. This would appear to be the only activity in the game that will reward this resource, outside of the challenges and season pass.
Players will need to farm up Ether by completing activities, then create a Key Code in the Quests tab by clicking on the Splicer Gauntlet and going in the items menu. They can then load into Override and finish the event, opening the special Conflux Chest at the end, at which point they may get a Decrypted Data drop.