What an ECG password actually reads
An electrocardiogram records the tiny electrical changes produced as the heart contracts and resets. Sensors on a wearable or another device can capture that signal as a repeating waveform. An authentication system turns features of the waveform—such as the shape and spacing of its peaks—into a template and compares a fresh reading with it.
That makes the method different from checking a pulse. A pulse sensor measures blood flow; an ECG sensor detects electrical activity. The resulting pattern can help distinguish one person from another, much as a fingerprint’s ridges do, without requiring the person to remember a code.
The hard part is matching a living signal
A fingerprint is relatively stable, but an ECG is not a perfectly fixed stamp. Its appearance can shift with movement, sensor placement, and changes in the body. A system therefore has to tolerate ordinary variation while still rejecting someone else’s signal. Too strict, and it may lock out the legitimate user; too loose, and it may accept the wrong one.
The sensor also has to make reliable contact and capture a clear reading. That can make ECG authentication useful in devices already worn against the skin, but less convenient when a person simply wants to unlock a phone held in the hand.
A biometric is not a replaceable secret
A heartbeat pattern can serve as one layer of identity checking, but it is not a magic password. Biometric data must be protected, and a person cannot readily replace a compromised heart pattern the way they can change a PIN. The practical promise is convenience: a body signal can help confirm who is holding a device, provided the system can read it consistently and safeguards the data it stores.
