The quest for perfect quantum oblivious transfer (QOT) with informationâtheoretic security remains a challenge, necessitating the exploration of computationally secure QOT as a viable alternative. Unlike the unconditionally secure quantum key distribution (QKD), the computationally secure QOT relies on specific quantumâsafe computational hardness assumptions, such as the postâquantum hardness of learning with errors (LWE) problem and quantumâhard oneâway functions. This raises an intriguing question: Are there additional efficient quantum hardness assumptions that are suitable for QOT? In this work, leveraging the dihedral coset state derived from the dihedral coset problem (DCP), a basic variant of OT, known as the allâorânothing OT, is studied in the semiâquantum setting. Specifically, the DCP originates from the dihedral hidden subgroup problem (DHSP), conjectured to be challenging for any quantum polynomialâtime algorithms. First, a computationally secure quantum protocol is presented for allâorânothing OT, which is then simplified into a semiâquantum OT protocol with minimal quantumness, where the interaction needs merely classical communication. To efficiently instantiate the dihedral coset state, a powerful cryptographic tool called the LWEâbased noisy trapdoor clawâfree functions (NTCFs) is used. The construction requires only a threeâmessage interaction and ensures perfect statistical privacy for the receiver and computational privacy for the sender.