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. 2022 Sep 6;22(18):6741. doi: 10.3390/s22186741
Step1: Communication over the quantum channel
King: Generate multi-stream of bits a, b, and c, and each bitstream length of n
FOR every bit from a multi-bit source S
  select randomly from (a,b,c) resulting base S {a[i], b[i], c[i]}
END FOR
FOR every bit from a multi-bit source S
Produce a photon
IF S[aibici] = 000 and base[i] = RL1 polarize the photon state is either 0° or 180°
IF S[aibici] = 001 and base[i] = RL2 polarize the photon state is either 30° or 210°
IF S[aibici] = 010 and base[i] = SRL1 polarize the photon state is either 45° or 225°
IF S[aibici] = 011 and base[i] = SRL2 polarize the photon state is either 60° or 240°
IF S[aibici] = 100 and base[i] = LOG1 polarize the photon state is either 90° or 270°
IF S[aibici] = 101 and base[i] = SLOG1 polarize the photon state is either 120° or 300°
IF S[aibici] = 110 and base[i] = ROG2 polarize the photon state is either 135° or 315°
IF S[aibici] = 111 and base[i] = SROG2 polarize the photon state is either 150° or 330°
transmit raw bit stream raw[aibici] to Sing
END FOR
Sing:
FOR every raw bit stream raw[aibici] obtained
generate RANDOM (raw[aibici]) results base1[i]
measure raw bit stream raw1[aibici] with corresponding base1[i]
finally obtained bit stream is result 1[i]
END FOR
Step 2: Communication over the classical channel
    2.1: Transmission
      FOR every bit stream of result 1[i]
         transmit base 1[i] to King
      END FOR
    2.2: Key generation from raw bit stream
      King:
      FOR each bit result 1[i]
         IF base[i] != base1[i]
           discard bit result[i] from string S
         END IF
      END FOR
      Sing:
      FOR each bit result 1[i]
         IF base 1[i] != base[i]
           discard bit result 1[i] from string S
         END IF
      END FOR
Step 3: Fault-tolerant valuation to predict the level of security
    King and Sing:
      FOR a group of bits selected randomly from the bit stream S
         IF result 1[i] = result[i] and base[i] = base 1[i]
              No or less error rate and snooping
                discard result1[i] and result[i]
         END IF
         ELSE
              Major error rate and snooping
              discard the entire bit stream and retransmit
         END ELSE
      END FOR
Step 4: Final key production
  Finally filtered bits from the bit streams result 1[i] and result[i] after successful execution of IF block of Fault-tolerant valuation is our resultant key.