Player terminology is confused

[bennetyee]

oasis-core/secret-sharing/src/churp/player.rs

Line 16 in 6dcf9d8

impl Player {

In secret sharing schemes, the terminology traditionally is that the shareholders are the players of a (cryptographic) game. There is sometimes a single honest dealer who shares out the initial secret; sometimes there are T+1 untrusted dealers who cooperatively create a secret sharing polynomial with a constant term no single dealer could determine/control. The "game" between the dealer(s) and players involve the initial distribution / setup of the shares, including verification (if verifiable secret sharing). After the initial setup, the dealer is no longer necessary for the reconstruction of the secret, or for generating derived keys (as in the KDC case), or for proactivization (since the zero-holed polynomial is done VSS style).

The Player here is what would be called the client in a client/server setup in a key distribution scheme. In secret sharing based key distribution, instead of a single trusted server, we have instead have a set of servers -- the players of the cryptographic game earlier -- among which we believe, as a security assumption, the adversary could not have compromised more than a threshold number. Clients could be compromised too: they're authorized to obtain their key and when compromised, their key becomes exposed but no master keys.