I recently found out about Quark here: https://en.bitcoinwiki.org/wiki/Quark_Algorithm
Apparently it is a proof-of-work algorithm used by several cryptocurrencies and is based on a single-level hash function, which consists of 9 different levels of encryption by six cryptographic algorithms. It also says that Quark provides a "64-bit" protection against hackers.
Isn't 64-bits of protection considered rather insecure? I'm sure a hacker with sufficient computing power can break 64-bits of security given enough time and money. Or am I missing something?