The safety measure of data communication is its encryption to prevent unauthorized access during transit over the Internet. Security of cryptographic keys from intrusions is among the top security concerns. To transmit secret data, data security algorithms apply cryptography techniques with suitably decided common keys in a session. The algorithms that are cryptographically secured must maintain confidentiality by using session-based common keys. This raises another issue: secure sharing of these keys among nodes. Trusted Third Party (TTP) is, therefore, the only primary solution for secure key exchange. The security of the key is ensured by continuously updating its value based on some graph nodes. The message can be securely transmitted through the graph-based key chain mechanism. This paper introduces a graph-based key chain mechanism to strengthen data transmission security. Using cyclic graph traversal and trusted third-party key exchange sharing, a proposed framework keeps updating its keys dynamically to circumvent the potential breaches. The result shows more security with less vulnerability than the traditional method. A detailed analysis of key generation for data encryption is thus closely tied to the underlying graph traversal methodology.