Ask HN: What are some good resources on encoded/encrypted search?

I'm interested in learning more about the "encoded/encrypted search" domain (searching encrypted data without having to decrypt it). Looking for some good resources to learn more about it.

I've obviously already asked the AI overlords, but wanted to see what suggestions I get here. Thanks in advance!

Things I'm curious about: - current methods used - challenges to be solved - use cases, markets, and current products - really anything else that's applicable