  We study a simple graph-based classical secret sharing scheme: every player's
share consists of a random key together with the encryption of the secret with
the keys of his neighbours. A characterisation of the authorised and forbidden
sets of players is given. Moreover, we show that this protocol is equivalent to
the graph state quantum secret sharing (GS-QSS) schemes when the secret is
classical. When the secret is an arbitrary quantum state, a set of players is
authorised for a GS-QSS scheme if and only if, for the corresponding simple
classical graph-based protocol, the set is authorised and its complement set is
not.
