In a previous post I estimated that the Heichal Building had about 42 doors that needed keys to unlock them. A large part of this calculation assumed that the doors connecting the 38 tauim [small rooms] to each other required keys, although I could not find a direct source that this was true.
I recently came across a discussion in Ezras Kohanim (Middos 4:3 s.v. ושלשה פתחים) where he cites Piskei Tosafos §9 to Tractate Tamid who writes that there were "one hundred Amarkalin [Temple officers] holding the keys of the Courtyard." Ezras Kohanim assumes that there were 100 keys, one per officer, and he then attempts to work out which Temple doors these 100 keys opened. I was happy to see that in the course of his calculation he clearly states that many of these keys were for the doors between the tauim.