We came across this interesting article recently, it’s about how an attacker can perform a denial-of-service attack by feeding perverse input to a system that uses weak hashing algorithms. This is referred to as a Hash DoS, and the specific target mentioned in the article is btrfs. btrfs is a next-gen filesystem that’s expected to replace ext3/4 in Linux. It’s still considered experimental but is quite usable and maturing fast. This article piqued our interest because we’re using btrfs “for reals” here at Anchor. It’s well and good to say that, but the article isn’t very exciting unless you have a background in computer science. How would you explain Hash DoS to your parents, who probably don’t have a CompSci background? This is the internet, so the answer is cats….