Removes blinding using ephemeral key @rInv on (intermediate result) 
    @y \in Gt.

def deblind(rInv,y):
    """
    Removes blinding using ephemeral key @rInv on (intermediate result) 
    @y \in Gt.
    """
    # Verify types, then deblind using the values provided.
    assertScalarType(rInv)
    assertType(y, GtElement)
    return y ** rInv