I was wondering if interleaving the resulting crypted data with dummy bytes placed at random positions but known in advance by the peers could improve security (no matter the algorithm and strength used, this is just baby step theory here) or do the contrary (and why).
after Thomas answer, I realized that my question was not clear where the dummy bytes would go.
So I am interested in adding dummies in the ciphertext. After all encryption of the real text occurred. The net result is to make the ciphertext longer and not logical anymore.