WHY IT MATTERS: Digital Transformation

A SaaS company like Dropbox needs to update our systems constantly, at all levels of the stack. When it comes time to tune some piece of infrastructure, roll out a new feature, or set up an A/B test, it’s important that we can make changes and have them hit production fast.
Making a change to our code and then “simply” pushing it is not an option: completing a push to our web servers can take hours, and shipping a new mobile or desktop platform release takes even longer. In any case, a full code deployment can be dangerous because it could introduce new bugs: what we really want is a way to put some configurable “knobs” into our products, which a) give us the flexibility we need and b) can be safely tweaked in near real-time.
To satisfy this need, we built a system called Stormcrow, which allows us to edit and deploy “feature gates.” A feature gate is a configurable code path that calls out to Stormcrow to determine how to proceed.

In this post, we want to share more details of our current password storage mechanism and our reasoning behind it. Our password storage scheme relies on three different layers of cryptographic protections, as the figure below illustrates. For ease of elucidation, in the figure and below we omit any mention of binary encoding (base64).