What is the use of looted keys in Assassins creed brotherhood?

[Jagad]

I was playing Assassins creed brotherhood and suddenly I encountered with some bounty hunter. This bounty hunter sets up a dummy and then ambushes you. After that I just killed him and then I looted the dummy .Once I started to loot him it said that keys 1.So what does this keys do. Are those keys really useful to me? I can't find them in my inventory or any of the other menus. So please help me out on this as I am very anxious to know what they are.

[desilva]

Even I faced with the same keys and I feel that maybe it’s for those blocked off memories or a requirement for a future DLC. But some say that all of the Leonardo's dummies have keys on them too. It is because testing your skills in the back area was something that was going to implement but it left out due to time. But then what happened is that they just rushed to make the game come out more sooner rather than later. This is what actually took place.

[Common]

I was playing this game and then just finished with the last assassination mission .After that I got the keys as well but they surprisingly don’t appear in the inventory and there is nothing on the map that shows a mission or any interaction. I thought that the guide must be saying something about it. So I checked for it. But even it didn’t say anything. So probably we need to wait a while to know what exactly it is.

[Abbie]

I haven’t encountered any keys as of yet. Where do we find these keys? I am feeling very left out looking at this. Have they just dropped the idea of having the keys? This is really very weird. As far as I know I just encountered with just one key when I killed someone. Actually I don’t remember whom I killed and when did I got that key. But I am sure that it wasn’t a bounty hunter whom I killed. So I just now need to find the bounty hunter and need to kill him.

[MacIntel]

I just wonder that the keys that we got might be for all those poor forgotten locks that we had come across earlier. So I feel that those keys might be used for those forgotten locks. I am just guessing on this and I am not at all sure about it. Maybe we all need to try the next time we will play the game. This will help us to know what the keys are for actually. But to be frank even I had encountered with this issue before but didn’t give much attention to it. Now I’ll surely try for it.

[AZUL]

Even I came across with some keys. When I finished giving Maria her feathers I started running around her room and then there was a cupboard present over there. Just checked into the cupboard and saw that there was a drawer open. Then I just peeped into the drawer and there were these keys present. But even I don’t know where to use these keys. I think the better solution would be to ask UBISOFT itself and they would provide us with the proper answer.