Table 2 Post-processing of raw key in the sifting step. Bob flips his bits to ensure correct correlation with Alice’s bit.

From: Measurement device-independent quantum key distribution with vector vortex modes under diverse weather conditions

Alice and Bob

Charlie’s measurement results

\(|\Psi \rangle ^{+}\)

\(|\Psi \rangle ^{-}\)

Vector basis

Bit flip

Bit flip

Scalar basis

Bit flip

Bit flip