It's a contemporary suspense romance. The heroine was genius in decryption or designing software and she started to help the hero and his military team. I remember a scene when the heroine went to the hero's home to give him cookies and found him and his team discussing a message or something else on the table and it was a code and she understood the message and apologized to them that she didn't mean to see it but they were surprised that she could decode it in few seconds. She started helping them.