**Bit concealment in GHZ states** - Anirban Roy

In an usual (k,n) threshold quantum secret sharing sceme, a secret
quantum state is divided among n parties, such that any k of them can
reconstruct the state, while any set of k-1 or fewer parties cannot. Here we
propose a bit concealment idea in a set of GHZ states where unless all
parties collaborate, they cannot learn the bit even with LOCC.