insecure pdf "encryption"
looks like some pdfs you find with password protection might not be that protected at all: https://v12.sh/blog/the-case-of-the-9bit-aes-key
╭──────╮╭──────╮ ║ ·─╮ ││ ╭─· ║ ║ ╭╯ · ││ · ╰╮ ║ ║ ·╰─╮ ││ ╭╯· ║ ╰─────┴╯╰┴─────╯📖
looks like some pdfs you find with password protection might not be that protected at all: https://v12.sh/blog/the-case-of-the-9bit-aes-key