  Quantum bit commitment (QBC) is insecure in the standard non-relativistic
quantum cryptographic framework, essentially because Alice can exploit quantum
steering to defer making her commitment. Two assumptions in this framework are
that: (a) Alice knows the ensembles of evidence $E$ corresponding to either
commitment; and (b) system $E$ is quantum rather than classical. Here, we show
how relaxing assumption (a) or (b) can render her malicious steering operation
indeterminable or inexistent, respectively. Finally, we present a secure
protocol that relaxes both assumptions in a quantum teleportation setting.
Without appeal to an ontological framework, we argue that the protocol's
security entails the reality of the quantum state, provided retrocausality is
excluded.
