The use of cryptography systems in cyber security domain has become a primary focus to maintain data confidentiality. Several cryptography solutions exist for protecting data against confidentiality attack. Due to the advancement of computing infrastructure, there is always a need for novel security solution to protect data and introduce more complexity to the intruder. In this paper, a novel graph-based crypto-system is proposed to provide data confidentiality during communication between users and devices. The proposed crypto-system uses a set of graphs of order n along with an operation defined over it to form a group algebraic structure. Using this group, plaintext, ciphertext, and secret key are represented as a graph. The encryption and decryption processes are performed over the graphs using the operation defined in the group. It is then demonstrated that the proposed crypto-system is valid, and for a large n value, brute-forcing attempts to derive the key from plaintext or ciphertext is computationally infeasible. © 2018 IEEE.