Match drop rate of strongboxes = 20%-30. No salvage boxes from missions, only keys small chance of getting a key mission, maybe 5%. Keys = rare salvage from games, rarity of a pack of two keys = to rarity of getting an officer weapon. Rarity of a single key slightly less than the rarity of getting (normal) salvage from pubs. Special super rare strongbox that only opens up to hacked keys (from the market) requires 5x keys to open and provides 10x normal keys, this strongbox is rare and is the only strongbox that can be acquired through mission, very low chance.

Speaking of which, all keys from missions and salvage are just strongbox keys.

Aurum keys are hacked strongbox keys which provide a 20% bonus to recieve rare salvage, and a 25% bonus to duplicate the salvage.

Aurum keys = better and more salvage

Login rewards

Every day you login you get ONE key, every 7 days you have a 25% chance of getting a aurum key. Statistically you can get one aurum key per month.

This provides a slight over-saturation of the strongbox to key ratio, but provides a steady stream of keys for normal play along with an incentive to buy aurum keys.

When using aurum keys you also get a treasure Hunter bonus which increases the chance of rare salvage to 100% after every 10 keys used.