Stripe powers our payment process. All card numbers are encrypted on disk with AES-256. Decryption keys are stored on separate machines. None of Ulyngo and Stripe’s internal servers and daemons are able to obtain plaintext card numbers; instead, they can just request that cards be sent to a service provider on a static whitelist. Ulyngo and Stripe’s payment process infrastructure for storing, decrypting, and transmitting card numbers run in separate hosting infrastructure and doesn't share any credentials with its primary services (API, website, etc.). More information via Stripe.