Tweakable Block Cipher based on Catalannumber

The present COVID pandemic has transformed a physical world to a digital world. Electronic communication has become a major part of the human life that leads to a threat to digital network. so, hiding and protecting the information against unintended persons is highly essential nowadays. This can be done by encryption process. Encryption techniques are derived from mathematical concepts like number theory, graph theory, and algebra. The present paper explains a tweakable block cipher using Catalan numbers of applied number theory. Here the Catalan number acts as a public key. A cyclic permutation is secret key between the legitimate users that acts as a tweak in encryption process.