this post was submitted on 16 Jul 2024
311 points (95.3% liked)
Technology
59534 readers
3195 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Oh, I did a dumb. Capacitive readers use the body's natural electrical signal to form an image of your fingerprint. You can trick them by using something conductive and running the right amount of electricity through.
Dead people don't work though. Not for very long at least.
Capacitive sensors don't measure the body's signals. Capacitance is a physical property of a material. The sensor puts out a signal and measures the response.
I can use a gallon of milk to scroll my phone. Just tried.
Capacitive sensors are looking at capacitance of a material, everything has this not just living things and it certainly doesn't require putting current through the material. You can for example get capacitive sensors for sensing the presence of cardboard, and they're often used for detecting metal parts (obviously tuned to the specific material). This is also why water droplets mess up touch screens (and the biometric sensor), because it's close enough to the capacitance of a finger (we're mostly water after all) to trick it and create false triggers.