In this paper, the authors encompass the study of security issues connected with existing ATMs and other electronic fund transfer mechanism. As the matter of fact that hackers are committing uninterrupted crimes; thus emphasis is given here to use Rijndael algorithm for matured cryptography techniques in order to combat such unethical attempts. Few endeavors have been reported so far to design the Rijndael hardware that attracted researchers worldwide. But most of them are based on conventional CMOS technology. Here, their novel approach is to improvise the Rijndael using one highly advanced technology called Single Electron Transistor (SET) Technology which is one most dominating successor in post CMOS era.