  This study proposes a simple and efficient one-out-of-two quantum oblivious
transfer (QOT) protocol based on nonorthogonal states. The nonorthogonal
property grants quantum bit immunity to some operations in order to achieve the
irreversible goal of discarding a message, resulting in a one-out-of-two
selection effect. In addition, it can also prevent entangled cheating from an
illegal agent. The resulting QOT protocol is therefore built directly on
quantum resources, rather than on a two-level structure which must first create
two classical keys using the quantum resources (all-or-nothing QOT), and then
build the one-out-of-two protocol from there. Furthermore, the proposed
protocol allows Alice to test Bob's loyalty by comparing the measurement
results. Moreover, the relationship with the no-go theorem is discussed in
detail; this relationship is often overlooked in other studies. The no-go
theorem discussion and security analysis demonstrate that the proposed protocol
does not belong to the no-go theorem constraint, and is secure against both
external and internal attacks. In addition, the efficacy analysis shows that
the proposed protocol is more efficient than other two-level structure
protocols.
