Electrocardiogram, better known as ECG or EKG, is a method used to measure and record the electrical potential generated by the heart on the skin. ECG data is unique to a user and can be used for authentication systems such as access or financial cards or for granting access to computing devices such as mobile devices. Electrode contact on a card or device are used to received ECG data which is processed to extract features of the ECG which are compared to a template for a user.