Light-weight secrecy system using channels with insertion errors: Cryptographic implications

A model of an encryption approach is analyzed from an information-theoretic point of view. In the model, an attacker faces the problem of observing messages through a concatenation of a binary symmetric channel and a channel with randomly inserted bits. The paper points out to a number of security related implications resulting from employing an insertion channel. It is shown that deliberate and secret-key-controlled insertions of random bits into the basic ciphertext provide a security enhancement of the resulting encryption scheme.