This is what you get when you have amateurs try and develop security systems. While I applaud them for at least trying, and I realize that hiring an actual security consultant is unlikely to happen, it pains me to see their security system as described.<p>A half-decent systems security architect (in the whole scheme of things) is not that expensive - I'm sure someone like @tptacek would provide a referral to someone charging less than $1000/hour who could, in a matter of two or three weeks, architect an actual secure solution, with HSMs, XofY authorization procedures and so on, that the good people at coinbase could (or not) go off and design/deploy.<p>[edit: Part of my pain at looking at this system, is seeing all the many, obvious flaws, that other industries that need security (military, banking, smart grids) have had to deal with and have solved in elegant, secure, reliable ways. I work in an industry where no one individual can be allowed to have excessive rights, privileges, or power over the system under their control. The many, many, many layers of security, audits, rights management, and AAA we have in place do so are impressive (though, ironically, one of the elements does involve acid-free 100 year paper in Safe Deposit boxes). Reading through the coinbase description though, is akin to reading about the encryption system created by someone who had never taken a cryptography course.<p>The outputs from both groups can be trivially shown to be completely flawed by those who've had the opportunity to see how it's properly done.<p>With that said, at least they are _trying_]