One-way distillable entanglement, a key measure of bipartite entanglement, has been notoriously difficult to compute due to its complex definition involving many copies and adaptive protocols. Researchers have made a breakthrough by discovering single-letter one-way distillable entanglement for non-degradable states, simplifying the computation process1. This advancement is significant as it provides a more efficient method for quantifying the optimal rate at which maximally entangled pairs can be extracted. The one-way distillable entanglement is crucial in understanding the operational capabilities of entanglement, a fundamental resource in quantum information processing. By simplifying the computation, researchers can better analyze and utilize entanglement in various quantum applications. This matters to practitioners as it enables the development of more efficient quantum protocols and algorithms, ultimately enhancing the security and capabilities of quantum systems, which is critical in the face of emerging geopolitical threats in the quantum realm.