We, the Chrome Security Team, propose that user agents (UAs) gradually change their UX to display non-secure origins as affirmatively non-secure. We intend to devise and begin deploying a transition plan for Chrome in 2015.
The goal of this proposal is to more clearly display to users that HTTP provides no data security.
We’d like to hear everyone’s thoughts on this proposal, and to discuss with the web community about how different transition plans might serve users.
We all need data communication on the web to be secure (private, authenticated, untampered). When there is no data security, the UA should explicitly display that, so users can make informed decisions about how to interact with an origin.
Roughly speaking, there are three basic transport layer security states for web origins:
We know that active tampering and surveillance attacks, as well as passive surveillance attacks, are not theoretical but are in fact commonplace on the web.
We know that people do not generally perceive the absence of a warning sign. (See e.g. The Emperor's New Security Indicators.) Yet the only situation in which web browsers are guaranteed not to warn users is precisely when there is no chance of security: when the origin is transported via HTTP. Here are screenshots of the status quo for non-secure domains in Chrome, Safari, Firefox, and Internet Explorer:
UA vendors who agree with this proposal should decide how best to phase in the UX changes given the needs of their users and their product design constraints. Generally, we suggest a phased approach to marking non-secure origins as non-secure. For example, a UA vendor might decide that in the medium term, they will represent non-secure origins in the same way that they represent Dubious origins. Then, in the long term, the vendor might decide to represent non-secure origins in the same way that they represent Bad origins.
Ultimately, we can even imagine a long term in which secure origins are so widely deployed that we can leave them unmarked (as HTTP is today), and mark only the rare non-secure origins.
There are several ways vendors might decide to transition from one phase to the next. For example, the transition plan could be time-based:
Or, vendors might set thresholds based on telemetry that measures the ratios of user interaction with secure origins vs. non-secure. Consider this strawman proposal:
The particular thresholds or transition dates are very much up for discussion. Additionally, how to define “ratios of user interaction” is also up for discussion; ideas include the ratio of secure to non-secure page loads, the ratio of secure to non-secure resource loads, or the ratio of total time spent interacting with secure vs. non-secure origins.
We’d love to hear what UA vendors, web developers, and users think. Thanks for reading! We are discussing the proposal on web standards mailing lists:
We have fielded various reasonable concerns about this proposal, but most of them have a good answer. Here is a brief selection.
(Please consider any external links to be examples, not endorsements.)