Researchers at ETH Zurich developed a sensor chip that cryptographically signs images, video and audio inside the device the moment a signal is recorded. The digital signature links the file to a specific camera or recorder, records the capture time and indicates whether the data were altered later.
The signatures can be stored in a publicly accessible, immutable ledger such as a blockchain. Anyone can then check a file by comparing its signature with the one in the ledger. If the data are signed at capture, later manipulation leaves traces and is hard to hide.
The idea started in a bioengineering laboratory and the chip in the new paper is a working prototype. The researchers say more development is needed before commercial use; they have filed a patent application and are looking at ways to lower manufacturing costs.
Difficult words
- signature — a code that shows file origin and changessignatures
- ledger — a public record that cannot be easily changed
- immutable — not able to be changed or removed
- prototype — an early working model for testing
- manipulation — a change made to data or information
- patent — a legal right to control an invention
- capture — the act of recording a sound or image
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think signing images at capture would make people trust photos and videos more? Why or why not?
- What concerns might people have about storing signatures in a public ledger?
- How could lower manufacturing costs affect the availability of this chip?
