  In this work, a canonical method to compute entanglement entropy is proposed.
We show that for two-dimensional conformal theories defined in a torus, a
choice of moduli space allows the typical entropy operator of the TFD to
provide the entanglement entropy of the degrees of freedom defined in a segment
and their complement. In this procedure, it is not necessary to make an
analytic continuation from the R\'enyi entropy and the von Neumann entanglement
entropy is calculated directly from the expected value of an entanglement
entropy operator. We also propose a model for the evolution of the entanglement
entropy and show that it grows linearly with time.
