Cryptographic security is of great importance. Biometrics play a vital role in modern authentication systems. Among all emerging biometrics, heart-based biometrics are promising because they are unique and hard to counterfeit. The current solutions on cardiac motion detection are either obtrusive or incapable of providing comprehensive cardiac motion information. To this end, we present Non-contact Cardiac Motion Sensing (NCMS), an end-to-end hardware and software solution, to sense and characterize the cardiac motion in a continuous, unobtrusive and user-friendly manner. We evaluate the performance of NCMS and compare the cardiac motion cycle on human subjects. Experimental results indicate the feasibility of NCMS to detect the cardiac motion and show the concept of a new modality in emerging heart-based biometrics.