Common methods of cracking a fingerprint sensor include creating a rubber model of a finger, copying a fingerprint onto a piece of tape, or getting a real finger from a person. Recently, we have found a combination of a fingerprint sensor and a heart rate sensor in several of the latest smartphones, which is expected to avoid this type of attack. In general, a smartphone fingerprint sensor maps a fingerprint to an on-chip capacitor matrix that is large enough to cover a finger. Next, the observed fingerprint pattern is compared to the stored pattern recorded during training by a software algorithm, taking into account some variations caused by finger placement, rotation, and pressure. The heart rate sensor operates on a different principle, sending an LED light source through human soft tissue reflected from the bone and receiving it by a sensor located near the LED. The amount of light received depends primarily on the amount of moisture (blood) in the soft tissue. When the heart is relaxed, the venous blood is less, and when the heart contracts, it expands significantly and produces a pulse. The combination of a capacitive fingerprint sensor and a heart rate sensor eliminates the need for separate contacts for each function, which is the approach taken by Samsung's Galaxy Note 8 and S9 phones. It also adds security to confirm the unlocking of the phone with a living finger. Goodix is ​​equipped with this type of sensor in several smartphones currently shipping. This combined sensor is actually smaller than the size of the fingerprint sensor alone. It adds a small chip to the capacitive fingerprint sensor chip to implement a small optical sensor array with only a small increase in chip cost. The added cost of this combined sensor comes primarily from external LEDs, as well as the addition of light-transmissive windows in the package (the cost of allowing the LED source to dissipate and allow reflected light to enter. Goodix does not recommend heart rate detection sensors because simple heart rate sensors may be less accurate, but they must be responsible for monitoring heart rate. For the sake of safety, the exact heart rate number is not important – the key is pulse. Therefore, the main advantage of the combination of fingerprint sensor and heart rate sensor is to make fingerprint recognition more secure and reliable. Next, we expect to add another temperature sensor to this type of fingerprint sensor combination to further ensure that the fingerprints are indeed from a lively blood. Solar home energy storage power supply SHENZHEN CHONDEKUAI TECHNOLOGY CO.LTD , https://www.szfourinone.com
Fingerprint sensors are quickly becoming the standard for unlocking and protecting smartphones. Their convenience and speed make them more popular than passwords, face recognition, iris recognition or user input.