Did we think AirDrop was anonymous? https://www.macrumors.com/2024/01/09/airdrop-cracked-chinese-authorities/
With that said, the details of this one look kind of exciting. Unfortunately the technical details are in Chinese and aren’t translating well for me.
Ok I found the TU Darmstadt paper that initially disclosed the flaws. TL;DR user hashing to implement a (bad) private set intersection protocol, and its trivially vulnerable to brute-force dictionary attacks.
Apple has known since 2019 and didn’t fix it! https://www.usenix.org/system/files/sec21-heinrich.pdf
