  The concept of Public- key cryptosystem was innovated by McEliece's
cryptosystem. The public key cryptosystem based on rank codes was presented in
1991 by Gabidulin -Paramonov-Trejtakov(GPT). The use of rank codes in
cryptographic applications is advantageous since it is practically impossible
to utilize combinatoric decoding. This has enabled using public keys of a
smaller size. Respective structural attacks against this system were proposed
by Gibson and recently by Overbeck. Overbeck's attacks break many versions of
the GPT cryptosystem and are turned out to be either polynomial or exponential
depending on parameters of the cryptosystem. In this paper, we introduce a new
approach, called the Smart approach, which is based on a proper choice of the
distortion matrix X. The Smart approach allows for withstanding all known
attacks even if the column scrambler matrix P over the base field Fq.
