At Station 1, we prepare a batch of particles that are correlated in a quantum way. Now we have to get some of the particles to Station 2 without destroying their correlations. Someone can intercept the particles on their way to Station 2, but once Station 1 knows the particles are at Station 2, the system is secure.
The operator at Station 1 performs a measurement on a particle there that changes the spin of that particle, as well as a measurement on a desired quantum bit that we want to transmit to Station 2. This process produces 2 classical bits of information. This process destroys the correlation between the particle pair, and affects the particle at Station 2 but in a randomized way that is useless without the operator at Station 2 possessing the two classical bits (thus it is not faster-than-light communication).
Once the laser takes the two classical bits to Station 2, at the speed of light, the operator at Station 2 can use them to decide what measurement to perform on the paired particle. Once the correct measurement is performed, the quantum bit that we measured at Station 1 appears.
The security benefit is that by completing one risky journey from Station 1 to Station 2, we can allow many future quick, secure journeys.
The propagation happens at the speed of light because the classical bits are required to understand what has been teleported. Performing the measurements is much slower than the speed of light. The correlation can only be stored for very short periods of time, currently.
The operator at Station 1 performs a measurement on a particle there that changes the spin of that particle, as well as a measurement on a desired quantum bit that we want to transmit to Station 2. This process produces 2 classical bits of information. This process destroys the correlation between the particle pair, and affects the particle at Station 2 but in a randomized way that is useless without the operator at Station 2 possessing the two classical bits (thus it is not faster-than-light communication).
Once the laser takes the two classical bits to Station 2, at the speed of light, the operator at Station 2 can use them to decide what measurement to perform on the paired particle. Once the correct measurement is performed, the quantum bit that we measured at Station 1 appears.
The security benefit is that by completing one risky journey from Station 1 to Station 2, we can allow many future quick, secure journeys.
The propagation happens at the speed of light because the classical bits are required to understand what has been teleported. Performing the measurements is much slower than the speed of light. The correlation can only be stored for very short periods of time, currently.