We address the question of the implementation of long-distance
device-independent quantum key distribution (DI QKD) by proposing two
experimentally viable schemes. Those schemes only use spontaneous
parametric down-conversion (SPDC) sources and linear optics. They
achieve favorable key rate scaling proportional to the square root of
channel transmittance ηt, matching the twin-field protocol
advantage. We demonstrate positive asymptotic key rates at detector
efficiencies as low as 80%, bringing DI QKD within the reach of current
superconducting detector technology. Our security analysis employs the
Entropy Accumulation Theorem to establish rigorous finite-size bounds,
achieving finite-key rates at a detector efficiency of 89%. This work
represents a critical milestone toward device-independent security in
quantum communication networks, providing experimentalists with
practical implementation pathways while maintaining the strongest
possible security guarantees against quantum adversaries.