An open-source camera that proves a photo is real using steganography

Proof of Capture: Apple Reference Image, but open source and using steganography

The author and Alex Hornstein built an open-source camera that embeds a cryptographic signature into the pixels via steganography, proving a photo was captured by a real sensor. Signing uses an ATECC608 secure element whose private key never leaves the chip. The current version signs a perceptual hash with a frequency-domain watermark that survives WhatsApp-grade compression. Apple just announced Reference Image with a similar goal but keeps the root of trust inside Private Cloud Compute and doesn't use C2PA. Hardware cost is under $100; code is open source.

Why it matters: Apple shipped Reference Image yesterday, and an open-source implementation lands today — the timing alone carries signal. The technical approach is substantive: hardware-backed signing via ATECC608, perceptual hashing with frequency-domain watermarking that survives compressio...