BB84 Quantum Key Distribution: Difference between revisions

**<math>n</math> number of total rounds of the protocol.

**<math>\ell</math> size of the secret key.

**<math>X_i, Y_i</math> bits of input of Sender and Receiver, respectively, that define the measurement basis.

**<math>A_i,B_i</math> bits of output of Sender and Receiver, respectively.

**<math>K_A,K_B</math> final key of Sender and Receiver, respectively.

**<math>Q_X</math> is the quantum bit error rate QBER in the <math>X</math> basis.

**<math>Q_Z</math> is the quantum bit error rate QBER in the <math>Z</math> basis estimated prior to the protocol.

**<math>H</math> is the Hadamard gate. <math>H^{0} = I, H^{1} = H</math>.

**<math>\gamma</math> is the probability that Sender (Receiver) prepares (measures) a qubit in the <math>X</math> basis.

**<math>\epsilon_{\rm EC}</math>, <math>\epsilon'_{\rm EC}</math> are the error probabilities of the error correction protocol.

**<math>\epsilon_{\rm PA}</math> is the error probability of the privacy amplification protocol.

**<math>\epsilon_{\rm PE}</math> is the error probability of the parameter estimation.