Resolved!
The issue was related to conversion to string. I used the following function for conversion now.
Private Function ByteArrayToString(ByVal arrInput() As Byte) As String
Dim i As Integer
Dim sOutput As New StringBuilder(arrInput.Length)
For i = 0 To arrInput.Length - 1
sOutput.Append(arrInput(i).ToString("X2"))
Next
Return sOutput.ToString()
End Function