In the new light quest step "Escalation Protocol: Conquer and Acquire" it states:
[i]Defeat the final wave in Escalation Protocol with a fully charged Encrypted Cache Key to open the final chest and retrieve your reward.
Rasputin Key Fragments drop occasionally during Nightfall strikes. Collect 7 Key Fragments and trade them to Ana Bray for an Encrypted Cache Key. Charge your Cache Key by completing rounds of Escalation Protocol.[/i]
This is now misleading as the cache keys and key fragments are no longer in the game.