Well-deployed technologies
The first line of defense for users, and the unit of isolation for Web apps is the same-origin policy that roughly limits what a Web application can access to content and data hosted on the same origin, i.e. the combination of URL scheme, domain name and port.
For legacy reasons, this policy is not as stringent on some parts of the Web platform, exposing users to greater attack surface via cross-site scripting or cross-site request forgery. To enable Web application authors to reduce the attack surface beyond what legacy requires, the Content Security Policy offers hooks that severely limits damages that an attacker could hope to achieve. An application delivered over a secure channel with CSP enabled can assure that users receive it as it was intended to be executed.
To further strengthen the integrity of their applications, Web developers can make use of the proposed Subresource integrity mechanism that makes it possible to block man-in-the-middle attacks or compromised third-parties providers.
The Mixed Content specification helps to migrate the Web toward being secure by default, by setting clear rules as to when content that is not served over HTTPs can or cannot be loaded from an HTTPs page.
In applications that aggregate content from multiple (possibly untrusted) sources, the HTML5 iframe sandbox attribute makes it possible to restrict the kind of interactions third-party embedded content can make use of.
The Web Cryptography API provides the necessary tools to encrypt data for storage and transmission from within Web applications, with access to pre-provisioned keys via the WebCrypto Key Discovery API.
For users that wish to indicate their preferences not to be tracked across Web applications and sites, the Tracking Preference Expression (also known as Do No Track) enables browsers to communicate explicitly their wish to content providers, and to determine whether a given content provider asserts fulfilling that wish. Not all content providers honor users' expressed preferences though.
| Feature | Specification | Maturity | Current implementations |
|---|---|---|---|
| Strengthened security | Content Security Policy Level 2 |  | Shipped |
| Subresource Integrity | | Experimental Shipped | |
| Mixed Content |  | Shipped | |
| sandbox iframe attribute in HTML 5.2 | | Shipped | |
| Encryption | Web Cryptography API | | Shipped |
| WebCrypto Key Discovery |  | ||
| Tracking Protection | Tracking Preference Expression (DNT) | | N/A |
Technologies in progress
Many sensitive APIs, e.g. those that expose mobile device sensors, are gated by a request for user consent; while these requests give control to the user, they can be sometimes hard to integrate in the overall user experience without visibility on which permission has been granted or denied. The Permissions API aims at fixing this.
To facilitate the authentication of users to on-line services, the Web Application Security Working Group is proposing a Credential Management API that lets developers interact more seamless with user-agent-managed credentials.
Building on the multi-factor authentication work of the FIDO Alliance, Secure Authentication aims to standardize multi-factor authentication for the Web, using the combination of "something you have" with "something you know," so that hacking a password database is no longer sufficient to hijack user accounts.
Secure Contexts recommends that powerful features of the Web platform, including application code with access to sensitive or private data, be delivered only in secure contexts, over authenticated and confidential channels that guarantee data integrity. As the draft indicates, "delivering code securely cannot ensure that an application will always meet a user's security and privacy requirements, but it is a necessary precondition."
Web sites with a lot of existing content set up to use resources loaded over HTTP can find the task of migrating that content to HTTPs daunting. The Upgrade Insecure Requests specification helps that migration by instructing the browser to load these resources over HTTPs.
The User Interface Security and the Visibility API document proposes to eliminate clickjacking by assuring element visibility at the graphics rendering level. For instance, a developer deploying it can assure that users clicking their site's "pay" button aren't being tricked into transferring their bank balances to an imposter instead.
| Feature | Specification | Maturity | Current implementations |
|---|---|---|---|
| Identity Management | Credential Management Level 1 |  | Under consideration In development Shipped |
| Authentication | Web Authentication: An API for accessing Public Key Credentials - Level 1 | | Experimental Shipped |
| Secure contexts | Secure Contexts | | Under consideration In development Shipped |
| HTTPs adoption | Upgrade Insecure Requests | | Under consideration Shipped |
| Sandboxing | User Interface Security and the Visibility API | |
Exploratory work
Hardware Based Secure Services aims to improve the levels of assurance to which users and application providers are able to protect their online accounts and communications, by making hardware security services available to the Web.
| Feature | Specification | Group | Implementation intents |
|---|---|---|---|
| Authentication | Hardware Based Secure Services features | Hardware Based Secure Services Community Group | N/A |
Discontinued features
- HTTP request filtering
- The Entry Point Regulation specification provided another layer of strengthening security. It defined a mechanism to filter the type of HTTP requests that can be made from external sites, reducing risks of cross-site script and cross-site request forgery. Work on this specification has been discontinued for the time being.