Editing GHZ-based Quantum Anonymous Transmission (section)

==Protocol Description==
Receiver <math>R</math> is determined before the start of the protocol. <math>S</math> holds a message qubit <math>|\psi\rangle</math>.
# Nodes run a collision detection protocol and determine a single sender <math>S</math>.
# A trusted source distributes <math>n</math>-partite GHZ state to every player, <math>|GHZ\rangle = \frac{1}{\sqrt{2}} (|0^n\rangle + |1^n\rangle)</math>.
# Anonymous entanglement:
## Sender <math>S</math> and receiver <math>R</math> do not do anything to their part of the state.
## Every player <math>j \in [n] \setminus \{S,R\}</math>:
### Applies a Hadamard transform to her qubit,
### Measures this qubit in the computational basis with outcome <math>m_j</math>,
### Broadcasts <math>m_j</math>.
## <math>S</math> picks a random bit <math>b \in_R \{ 0,1 \}</math> and broadcasts <math>b</math>.
## <math>S</math> applies a phase flip <math>Z</math> to her qubit if <math>b=1</math>.
## <math>R</math> picks a random bit <math>b' \in_R \{ 0,1 \}</math> and broadcasts <math>b'</math>.
## <math>R</math> applies a phase flip <math>Z</math> to her qubit, if <math>b \oplus \bigoplus_{j \in [n] \setminus \{S,R\}} m_j = 1</math>. </br> <math>S</math> and <math>R</math> share anonymous entanglement <math>|\Gamma\rangle_{SR} = \frac{1}{\sqrt{2}} (|00\rangle + |11\rangle)</math>.
# <math>S</math> uses the quantum teleportation circuit with input <math>|\psi\rangle</math> and anonymous entanglement <math>|\Gamma\rangle_{SR}</math>, and obtains measurement outcomes <math>m_0, m_1</math>.
# The players run a protocol to anonymously send bits <math>m_0,m_1</math> from <math>S</math> to <math>R</math> (see [[GHZ-based Quantum Anonymous Transmission #Further Information|Further Information]] for details).
# <math>R</math> applies the transformation described by <math>m_0,m_1</math> on his part of <math>|\Gamma\rangle_{SR}</math> and obtains <math>|\psi\rangle_{SR}</math>.