Yeah, it's unauthenticated encryption, but think about their threat model. It's not about protecting integrity (the code signing takes care of that), it's about protecting the code from prying eyes (aka DRM). And the tradeoff with speed is likely why they choose CTR. That has bitten them in the ass before with key reuse, but by PS4 they've had about 10 years of experience with the SELF format now. While I doubt the format is completely secure, it's likely easier to find a flaw in FreeBSD9 (which is why CTurt tried to say).