As an important resource of the quantum information engineering, to explore its' possible
applications and limits in the field of the secure communication is very necessary. In the paper we
analyse the problem of the security of quantum secret sharing with Smolin bound entangled states as
the channel quantum state. An intercept-resend strategy of the inner of the legal communicators is
proposed to attack the security without be detected by the checking procedure with comparing the
results of single-qubit measurement. A conclusion that quantum secret sharing only with Smolin bound
entangled states as the channel quantum state isnot unconditionally secure is attained, and a general
proof in terms of the quantum correlation is given.
We propose a scheme for generating entangled states of light fields. This scheme only requires the cross-Kerr
nonlinear interaction between coherent light-beams, followed by a homodyne detection. Therefore, this scheme is
within the reach of current technology. We study in detail the generation of the entangled states between two modes,
and that among three modes. In addition to the Bell states between two modes and the W states among three modes,
we find plentiful new kinds of entangled states. Finally, the scheme can be extend to generate the entangled states
among more than three modes.