  It is shown that the event horizon of 4D black hole or $ds^2 = 0$ surfaces of
multidimensional wormhole-like solutions reduce the amount of information
necessary for determining the whole spacetime and hence satisfy the Holography
principle. This leads to the fact that by matching two metrics on a $ds^2 = 0$
surface (an event horizon for 4D black holes) we can match only the metric
components but not their derivatives. For example, this allows us to obtain a
composite wormhole inserting a 5D wormhole-like flux tube between two
Reissner-Nordstr\"om black holes and matching them on the event horizon. Using
the Holography principle, the entropy of a black hole from the algorithm theory
is obtained.
