An anonymous-style blog by a former cryptographer on crypto mistakes, UUID security, bots, and why he left cryptography.
HN links it for its warning that UUIDs should not be used as authentication tokens, and one commenter who worked with the author vouches for him.
From https://littlemaninmyhead.wordpress.com/2015/11/22/cautionary-note-uuids-should-generally-not-be-used-for-authentication-tokens/
> Do not assume that UUIDs are hard to guess; they should not be used as security capabilities (identifiers whose mere possession grants access), for example.
HN discussion: https://news.ycombinator.com/item?id=10631806
This is the author: https://scholar.google.com.au/citations?user=9gs9StcAAAAJ&hl=en&oi=ao
Not a shill. Source: worked with him.
This post of his is an interesting read and might give a bit more background to the what you saw: https://littlemaninmyhead.wordpress.com/2017/10/23/why-i-left-cryptography/