Suppose you have a single resource to be encrypted, and it should be accessible by multiple users. Is there a way to encrypt something such that multiple keys would work? I can't seem to find any such solution...
How do things like FileVault implement a Master Key, and multiple users? It seems like something MUST be possible... The only thing I can think of is to encrypt the resource using a shared secret, and the shared secret can be obtained by individuals either by their password or by their public/private keypair. This would actually mean you take a small resource (the shared secret) and make n-copies encrypted separately for n-individual users. It's not really using multiple keys to access the same resource; it's achieving the same end result effective only on a small scale. Is there a better way?
