Future Samsung smartwatch could use your veins for identity verification

"A wearable device comprising: a sensor configured to capture a vein image of a user; and a processor configured to: in response to a function or an application being selected by the user, control the sensor to capture the vein image of the user wearing the wearable device; identify the user by comparing the captured vein image with at least one registered vein image; and in response to determining that the identified user has an execution authority for the selected function or application, execute the function or the application."-Samsung patent filing
The patent, titled "Wearable Device And Method Of Operating The Same," was originally filed in July of last year. If the technology is as impressive as hoped, it could lead to the future use of heart beats as a way to verify identification.
source: USPTO via FastCompany, Phandroid