What is your perception of fingerprints phone unlock and the dead? do you think it is possible to use a dead person’s fingerprint to unlock his phone?
In March 2020, Yuri Vinogradov a Belarusian posted a video showing how he used a broken thumb to successfully unlock a fingerprint-protected smartphone.
Of course, he didn’t cut off his fingers deliberately. The fingers were accidentally sawn off by his father when he was operating the circular saw two months ago.
The broken fingers happened to be the ones his father usually used to unlock the phone, and it was kept frozen. Vinogradov said that he often sees in the movie the bridge segment where the other party’s fingerprints are successfully decrypted, so he wants to verify whether it is feasible.
Can A Severed Finger Be Used to Unlock A Phone?
He put his severed finger in hot water and used it to unlock his phone smoothly. For the records, the severed finger was heated to room temperature.
So he concluded that it is completely feasible to unlock the smartphone with a severed finger. However, I think this experiment is accidental and cannot represent all smartphones.
However, this event reminds me of a topic that was once hotly discussed on the Internet: after death, can fingerprints unlock mobile phones?
Apparently, both the severed finger and the corpse have stopped normal cell activity and blood transmission, and have lost their biological activity.
If the severed finger can successfully unlock the fingerprint lock, does it mean that the corpse is also OK?
If you want to know whether your fingerprint can unlock your phone after death, you need to understand the principle of fingerprint unlocking.
Let’s get to know the Principle of Fingerprints Unlocking
Fingerprints are a kind of magical existence. As you can see from the images above, there are only three types: skip pattern, bucket pattern, and bow pattern.
Interestingly, there are almost no two fingerprints that are exactly the same in the world. Even if they are identical twins, their patterns are highly similar, but the details and features are different.
Everyone’s fingerprints will remain the same from birth to death. Because of its uniqueness and singularity, fingerprints have always been used to assist criminal investigations, replace signatures and seals, or divination. After the development of smartphones, fingerprints were used to unlock the phone.
Types of Fingerprints
The first fingerprint unlocking phone is a push fingerprint unlocking smartphone released by Motorola Atrix which uses an optical sensor technology. The phone is unlocked by scanning your finger once or multiple times.
However, this phone does not really scan fingerprints but scans by fingers. Number of times to unlock.
The first fingerprint to unlock a smartphone
So How Does the Real Fingerprint Unlocking Work?
Fingerprint unlocking has a set of fingerprint recognition algorithms, through acquisition, image preprocessing, data feature extraction, feature matching, to complete the unlocking.
Step 1: Collect Fingerprints
When we get a new mobile phone with a fingerprint unlocking function, we will start to enroll/enlist fingerprints first.
At this time, the mobile phone will collect your fingerprint information. In terms of collection methods, there are mainly “sliding types” and “pressing types”.
Although the sliding type is low in cost, the collection success rate is also low. It requires continuous and standardized sliding motions to successfully collect the data.
So the most common collection method is the push type. The push-type is to press the finger to unlock the part on the sensor several times, and piece together a large area of the fingerprint pattern.
Step 2: Image Preprocessing
After the fingerprints are collected, the quality of the image will be evaluated. In addition, the images will be enhanced and refined to deal with interferences such as removing burrs, breaks, and the likes.
Step 3: Extract Features
After obtaining a clear image, the features should then be extracted. Technically, the pre-processed image will have a large number of false feature points, which will affect the fingerprint recognition performance and cause the false rejection rate and the false recognition rate to increase.
After the false feature points are removed, the extracted feature data will be stored.
Step 4: Feature Matching
The quality of the feature matching algorithm directly affects the performance, speed, and efficiency of recognition. The point matching algorithm based on fingerprint structure features is used to match the calibrated point set.
Comparatively, the fingerprint identification method currently used is mainly different from the image acquisition method.
How can we differentiate the various fingerprint technologies of capacitive fingerprint identification, ultrasonic fingerprint identification, and image optical fingerprint identification?
Principles of Commonly Used Fingerprint Recognition Technology
Capacitive Fingerprint Unlock
Capacitive fingerprint recognition technology is the most commonly used fingerprint recognition method on mobile phones.
Human cell activities will generate a weak current, and the fingerprint lines are uneven microscopically, so the contact between the silicon wafer and the electrolyte of the skin can form an electric field.
At this time, the sensor can collect the shape of the fingerprint and obtain the image. This will later be used to unlock. Through this principle, we can understand that when there is sweat or water on the hand, the phone lock with capacitive recognition technology cannot be unlocked.
Similarly, the under-screen fingerprint scanner will also not work due to complex electric field conditions. Hence, this method is more common in the home button unlocking and The rear is unlocked.
Ultrasonic Fingerprint Recognition
Ultrasonic fingerprint recognition can penetrate different materials. After scanning the finger with a specific frequency, the fingerprint ridges and valleys can be distinguished according to the generated echoes, and the corresponding images can be established.
Ultrasonic fingerprint recognition can penetrate metal, glass, and other materials, and can realize fingerprint recognition under the screen. At the same time, ultrasonic fingerprint recognition is basically not affected by dirt, water, etc. on the surface of the finger.
Optical fingerprint Recognition
Optical recognition is an earlier fingerprint recognition technology. It is usually composed of a light source and a triangular prism photosensitive component.
The light emitted by the light source passes through a prism and then irradiates the finger surface. The light reflected from the finger surface carries fingerprint information and is projected onto the photosensitive component through the prism again.
After the sensory component recognizes the fingerprint information, the unlock is realized. Traditional optical technology is mainly used in attendance machines, access control, and security inspection systems. Optical recognition can also be used for under-screen fingerprint unlocking on a full screen.
However, regardless of whether the body itself has electricity or not, capacitive fingerprint recognition technology seems to be prone to bypass.
Fingerprints Phone Unlock and the Dead
On April 8, 2020, an intelligence agency named Talos used 3D printing technology to forge fingerprints and unlocked 8 different types of fingerprint unlocking devices with a success rate of 80%.
The materials they used for printing were resin, clay for carving, etc., and they made more than 50 molds.
They solved the problem of the clarity of the fingerprint image and the conductivity of the material, and the sensor was successfully activated and unlocked.
In conclusion, even if the human body loses biological activity and the fingers become “lifeless”, and electricity is applied to the deceased’s fingerprint before the deceased’s fingerprint is deformed, there will be an electric current flowing through the deceased’s fingers.
It is therefore possible to unlock on the phone through the fingerprint. Of course, this is just a theoretical guess.