Ask HN: How do you share passwords/keys between different companies/departments?

Background: I work in Marketing and am responsible for the "corporate Google account" with which I create Recaptcha, Google Maps, andsoon keys/passwords and other senstive stuff.

Our developer team is located in another city, we collaborate through the Attlastian product portfolio. At the moment I share those keys through a specific Confluence page with my developers, but the permission management per page in Confluence is such a PITA and is becoming unbearably annoying the more I use it.

What would be a more "conveniente" and still secure way to share those senstive data with the devs? TIA.