[Cross-posted on the Google Online Security Blog]

We work hard to keep you safe online. In Chrome, for instance, we warn users against malware and phishing and offer rewards for finding security bugs. Due in part to our collaboration with the research community, we’ve squashed more than 700 Chrome security bugs and have rewarded more than $1.25 million through our bug reward program. But as Chrome has become more secure, it’s gotten even harder to find and exploit security bugs.

This is a good problem to have! In recognition of the extra effort it takes to uncover vulnerabilities in Chrome, we’re increasing our reward levels. We’re also making some changes to be more transparent with researchers reporting a bug.

First, we’re increasing our usual reward pricing range to $500-$15,000 per bug, up from a previous published maximum of $5,000. This is accompanied with a clear breakdown of likely reward amounts by bug type. As always, we reserve the right to reward above these levels for particularly great reports. (For example, last month we awarded $30,000 for a very impressive report.)

Second, we’ll pay at the higher end of the range when researchers can provide an exploit to demonstrate a specific attack path against our users. Researchers now have an option to submit the vulnerability first and follow up with an exploit later. We believe that this a win-win situation for security and researchers: we get to patch bugs earlier and our contributors get to lay claim to the bugs sooner, lowering the chances of submitting a duplicate report.

Third, Chrome reward recipients will be listed in the Google Hall of Fame, so you’ve got something to print out and hang on the fridge.

As a special treat, we’re going to back-pay valid submissions from July 1, 2014 at the increased reward levels we’re announcing today. Good times.

We’ve also answered some new FAQs on our rules page, including questions about our new Trusted Researcher program and a bit about our philosophy and alternative markets for zero-day bugs.

Happy bug hunting!

Posted by Tim Willis, Hacker Philanthropist, Chrome Security Team

In January, we told you about Chrome Apps for Mobile, a project based on Apache Cordova to run your Chrome Apps on both Android and iOS. The project provides a native application wrapper around your Chrome App, allowing you to distribute it via the Google Play Store and the Apple App Store. Cordova plugins give your App access to a wide range of APIs, including many of the core Chrome APIs. The newest version of Chrome Apps for Mobile includes Chrome APIs for identity, Google Cloud Messaging (GCM) and rich notifications, as well as an improved developer workflow and modern WebView capabilities extended to older versions of Android.

The developer workflow for Chrome Apps for Mobile is now significantly faster and simpler with the new live deploy feature. With live deploy, you can instantly preview the Chrome App you’re editing, running right on your Android or iOS device. When you make a change to the code, you will be able to see it straight away. Live deploy is available in both Chrome Dev Editor (CDE) and the Chrome Apps for Mobile command line tool.

Chrome Apps are at their best when they leverage the powerful functionality and performance of the latest Chromium WebView. The introduction of an updated WebView into Android KitKat paved the way for advanced features such as WebRTC, WebAudio and Accelerated 2D Canvas, and we will continue to see improvements with each new Android release. However, now you have a way to leverage the latest Chromium WebView on any device running Android versions back to Ice Cream Sandwich by bundling your Chrome App with an embeddable Chromium WebView, provided by the Crosswalk open source project.

To show Crosswalk in action, we have taken the Topeka Polymer Web App released at I/O and packaged it as a Chrome App for Mobile, available for you to try out on Android.


The Topeka Android app uses an embedded Crosswalk WebView to achieve smooth performance even on older versions of Android, enabling a full fidelity material design UI with fluid animations and no polyfills. Crosswalk is now readily available through the Chrome Apps for Mobile tooling and should be used with an understanding of its advantages and tradeoffs.

Using Chrome Apps, you can now build performant and capable applications that target desktop, Android, and iOS devices. To get started, take a look at our documentation. As always, we welcome your feedback on Stack Overflow and our G+ Developers page.

Posted by Michal Mocny, Chrome Apps for Mobile Engineer and Mobile Magic Maker

We all develop websites on our desktop and laptop machines, so we tend to initially develop for the desktop experience. But that's increasingly out of sync with our users who, more and more, consume the web on mobile. To deliver a great experience for the web, we need to accurately experience it on mobile. Chrome DevTools has had mobile emulation features for awhile, but it's still too disconnected from real device conditions and requires too much trial and error. Chrome 38 Beta includes a new Device Mode that puts you one click away from emulating mobile devices, inspecting media queries, and emulating flaky network conditions.

Every media query gets represented visually, so you can correlate your breakpoints with the viewport. Clicking one resizes the viewport, making it easier to iterate on your associated styles. If you want to edit the media queries themselves, right-click and jump to the line of CSS where it's defined.

Lastly, device emulation needs to accurately represent the connectivity of your mobile users. For example, a 3G connection significantly limits the experience of your website compared to your speedy office WiFi. The DevTools can now help you emulate the network conditions (both throughput and latency) of connectivity like EDGE, 3G, 4G – and even go offline.

The SHA-1 cryptographic hash algorithm has been known to be considerably weaker than it was designed to be since at least 2005 — 9 years ago. Collision attacks against SHA-1 are too affordable for us to consider it safe for the public web PKI. We can only expect that attacks will get cheaper.

That’s why Chrome will start the process of sunsetting SHA-1 (as used in certificate signatures for HTTPS) with Chrome 39 in November. HTTPS sites whose certificate chains use SHA-1 and are valid past 1 January 2017 will no longer appear to be fully trustworthy in Chrome’s user interface.

SHA-1's use on the Internet has been deprecated since 2011, when the CA/Browser Forum, an industry group of leading web browsers and certificate authorities (CAs) working together to establish basic security requirements for SSL certificates, published their Baseline Requirements for SSL. These Requirements recommended that all CAs transition away from SHA-1 as soon as possible, and followed similar events in other industries and sectors, such as NIST deprecating SHA-1 for government use in 2010.

We have seen this type of weakness turn into a practical attack before, with the MD5 hash algorithm. We need to ensure that by the time an attack against SHA-1 is demonstrated publicly, the web has already moved away from it. Unfortunately, this can be quite challenging. For example, when Chrome disabled MD5, a number of enterprises, schools, and small businesses were affected when their proxy software — from leading vendors — continued to use the insecure algorithms, and were left scrambling for updates. Users who used personal firewall software were also affected.

We plan to surface, in the HTTPS security indicator in Chrome, the fact that SHA-1 does not meet its design guarantee. We are taking a measured approach, gradually ratcheting down the security indicator and gradually moving the timetable up (keep in mind that we release stable versions of Chrome about 6 – 8 weeks after their branch point):

Chrome 39 (Branch point 26 September 2014)

Sites with end-entity (“leaf”) certificates that expire on or after 1 January 2017, and which include a SHA-1-based signature as part of the certificate chain, will be treated as “secure, but with minor errors”.

The current visual display for “secure, but with minor errors” is a lock with a yellow triangle, and is used to highlight other deprecated and insecure practices, such as passive mixed content.



Chrome 40 (Branch point 7 November 2014; Stable after holiday season)

Sites with end-entity certificates that expire between 1 June 2016 to 31 December 2016 (inclusive), and which include a SHA-1-based signature as part of the certificate chain, will be treated as “secure, but with minor errors”.

Sites with end-entity certificates that expire on or after 1 January 2017, and which include a SHA-1-based signature as part of the certificate chain, will be treated as “neutral, lacking security”.

The current visual display for “neutral, lacking security” is a blank page icon, and is used in other situations, such as HTTP.



Chrome 41 (Branch point in Q1 2015)

Sites with end-entity certificates that expire between 1 January 2016 and 31 December 2016 (inclusive), and which include a SHA-1-based signature as part of the certificate chain, will be treated as “secure, but with minor errors”.

Sites with end-entity certificates that expire on or after 1 January 2017, and which include a SHA-1-based signature as part of the certificate chain, will be treated as “affirmatively insecure”. Subresources from such domain will be treated as “active mixed content”.

The current visual display for “affirmatively insecure” is a lock with a red X, and a red strike-through text treatment in the URL scheme.



Note: SHA-1-based signatures for trusted root certificates are not a problem because TLS clients trust them by their identity, rather than by the signature of their hash.

In April we released chrome.gcm, an API that allows Chrome apps and extensions to use the Google Cloud Messaging (GCM) service to interact with their server-side components via push messaging. Since the new API offers significant improvements and has been used for push messaging in Chrome apps and extensions since May 2014, we are now deprecating the legacy chrome.pushMessaging API.

Developers will start to see a deprecation message in the console if they use chrome.pushMessaging, and no new Chrome apps and extensions will be accepted to the Chrome Web Store if they use the deprecated API. Beginning in mid-January 2015, Chrome apps and extensions that continue to use chrome.pushMessaging will be delisted in the Chrome Web Store. When upgraded to use chrome.gcm, these apps will once again be discoverable via searching and browsing the Web Store. In early March, the chrome.pushMessaging API will be removed and all Chrome apps and extensions that continue to reference it will be automatically disabled. They can be enabled once again when upgraded to use chrome.gcm.

For a high level overview of how an app or extension can leverage chrome.gcm, check out our Google I/O Bytes video. Learn how to upgrade your Chrome apps and extensions by consulting the chrome.gcm API documentation and following this tutorial. Lastly, subscribe to the GCM for Chrome Feedback group to ask questions, get help, and learn more about the transition.

Posted by Jake Leichtling and Filip Gorski, Product Manager and Software Engineer