"Signal is Expensive”, from CEO @Mer__edith, is very good. The transparency around infrastructure costs had me hooked from the start, but the ways they've rearchitected ubiquitous features (profile pictures, GIF sharing, finding contacts) to protect user privacy, that’s really stunning.
@JoshuaACNewman @donmccurdy @techghoul
It trusts SGX: https://signal.org/blog/private-contact-discovery/
So, it is sending contact lists in such a way that they cannot be extracted without a collusion between Signal and Intel.