This update concerns SeedHammer source code, which is used to run the controller program for the SeedHammer engraving machine. It runs on the same hardware as the SeedSigner - Raspberry Pi Zero or Zero W, a WaveShare 1.3 inch 240x240 LCD hat and a Pi Zero compatible camera with a OV5647 sensor.
"This release contains an important security feature, improved camera scanning, easier building on macOS."
"Upgrading is strongly encouraged for the improved security."
"Before this release nearby attackers could deduce a seed phrase from the sound of the engraving needle during engraving. With this release all seed phrases will be engraved with identical sound profiles."
"SeedQRs are also being engraved with identical sound profiles but notice only the seed words and QR codes are engraved in this manner."
"The sound profile still leaks the length of your seed, the master fingerprint and the output descriptor."
"Improved camera scanning; small QRs scan better, scanning QR codes off a bright screen in a dark environment works better, and finally inverted QRs scan (bright QR on dark background - the plate to the right).