Quality assessment of the security of sensitive information being sent over or stored in a medium is vital in the world of computing and communications. Hash-based message authentication codes (HMACs) is a tool that provides such security check using a cryptographic hash function coupled with a secret key. In this paper, an enhanced key generation algorithm of HMAC-MD5 using XOR bitwise operator and left circular shifting is proposed. Six randomness tests from the NIST statistical test suite

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... performed to the proposed method which is implemented on the existing Travel Order Management System. Results showed that the binary sequence of the generated key is random in all tests as Pvalues passed the minimum significant level. The computed P-values are as follows: Frequency (Monobit) Test = 0.503, Frequency Test within a Block = 0.349, Run Test = 0.553, Test for the Longest Run of Ones in a Block = 0.022, Approximate Entropy Test = 0.325, and Cumulative Sums Test = 1.000. This means that the generator provides unpredictable random sequence of key.