Meh, they have run into difficulties right now, but they have an army of mathematicians, they will find a way.
remember how DES got cracked in the 90s? Nothing is safe forever. Techniques and computing power will improve.
hell, if I was the NSA, I’ll sneak a backdoor into the tor project through bribes and intimidation (being open source doesn’t prevent this all the time, just look at phpmyadmin). Or just replace the binary on the site with a compromised version, barely anyone compiles it themselves anyways
PS:
I’m trying to make Oct. 20 take your shirt off for the NSA day, please take your shirt off in front of the webcam, and do a quick strip tease for the hard working NSA agents.