[Stripe Developer] [edited for clarification]

I appreciate your interest in the security of Stripe, I think we definitely share the same goals here (making everything as secure as possible). However, I think there's some misunderstanding in some posts (and in the blog post):

> [...] the Stripe.js code is instantiated within the user browser by an HTTP response from the server infrastructure owned by the merchant When Stripe.js is included within the user's browser by a (mandated https, not http) request, it comes directly from Stripe's servers, not from "the server infrastructure owned by the merchant."

Stripe.js isn't served from the merchant. It comes directly from Stripe. Stripe.js helps keep payment card data away from a merchants own servers.

Keeping card data away from someone's machines doesn't mean that they don't need to comply with the Payment Card Industry Data Security Standards, but it does make things quite a bit simpler.

In most cases it means that they're eligible for one of the light-weight self-assessment questionnaires.

PCI compliance, of course, shouldn't be where people stop thinking about security though. You're absolutely right that if the pointer on the merchant's site is changed to a malicious site, that's where the payment data will go. The merchant needs to keep that pointer safe in the same way that if you're redirecting to a hosted payment form or elsewhere, you need to make sure that isn't tampered with either. (A hosted form has the advantage that at least a customer can view the SSL cert but if they don't recognize the domain (or if the domain is obscure anyway), that's not much good.)

Being compliant with the PCI standards is important but it doesn't cover all of the very, very important points of web security.

We do take security very seriously, and if you happen to find a valid security issue with our service, we pay bounties[1] for properly disclosed vulnerabilities.

If you have any other questions, or would like to wax poetic about security or PCI please don't hesitate to send the security team an email at security@stripe.com or to email me personally at alex@stripe.com.

[1] https://stripe.com/help/security#rewards