Building the most private app store
Posted on June 2, 2016
| Hans-Christoph Steiner
App stores can work well without any tracking at all
Attackers are increasingly seeing app stores as a prime attack vector, whether it is aimed at the masses like XCodeGhost or very targeted like in FBI vs Apple. When we install software from an app store, we are placing a lot of trust in a lot of different parties involved in getting the source code from the original developer delivered to our device in a useful form.
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PanicKit: making your whole phone respond to a panic button
Posted on January 12, 2016
| Hans-Christoph Steiner
Our mobile devices do so many things for us, making it easy to communicate with people in all manners while giving us access to all sorts of information wherever we are. But in times of anxiety and panic, it is difficult to quickly use them. Will you be too shaky to type in your PIN or lock pattern? Will you have enough time to find your trusted contacts and send them a message?
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How to Migrate Your Android App’s Signing Key
Posted on December 29, 2015
| Abel Luck
It is time to update to a stronger signing key for your Android app! The old default RSA 1024-bit key is weak and officially deprecated.
What? The Android OS requires that every application installed be signed by a digital key. The purpose behind this signature is to identify the author of the application, allow this author and this author alone to make updates to the app, as well as provide a mechanism to establish inter-application trust.
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CipherKit reproducible builds
Posted on September 21, 2015
| Hans-Christoph Steiner
We have been on a kick recently with making our build process support “reproducible builds” aka “deterministic builds”. What is this reproducible thing? Basically, what that means is that you can run a script and end up with the exact same binary file as our official releases, be it a APK, JAR, AAR, whatever. That lets anyone verify that our releases are produced only from the source in git, without including anything else, whether deliberately or accidentally (like malware).
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Building a trustworthy app store that respects privacy
Posted on June 2, 2015
| Hans-Christoph Steiner
One core piece of our approach is thinking about very high risk situations, like Ai Weiwei or Edward Snowden, then making the tools for operating under that pressure as easy to use as possible. That means that we might occasionally come across as a little paranoid. It is important to dive into the depths of what might be possible. That is an essential step in evaluating what the risks and defenses are, and how to prioritize them.
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Phishing for developers
Posted on February 24, 2015
| Hans-Christoph Steiner
I recently received a very interesting phishing email directed at developers with apps in Google Play. One open question is, how targeted it was: did anyone else get this?
It turns out that Google has been recently stepping up enforcement of certain terms, so it looks like some people are taking advantage of that. It is a pretty sophisticated or manually targeted phishing email since they got the name of the app, email address, and project name all correct.
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Complete, reproducible app distribution achieved!
Posted on February 11, 2015
| Hans-Christoph Steiner
With F-Droid, we have been working towards getting a complete app distribution channel that is able to reproducibly build each Android app from source. while this may sound like a mundane detail, it does provide lots of tangible benefits. First, it means that anyone can verify that the app that they are using is 100% built from the source code, with nothing else added. That verifies that the app is indeed 100% free, open source software.
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First working test of IOCipher for Obj-C
Posted on January 26, 2015
| Hans-Christoph Steiner
Every so often, we revisit our core libraries in the process of improving our existing apps, and creating new ones. IOCipher has become a standard part of our apps since it provides a really easy way to include encrypted file storage in Android apps. And we are now working on spreading it to iOS as well, headed up by Chris Ballinger, with the first preliminary tests of IOCipher for Obj-C. Testing and contributions are most welcome!
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CipherKit updates: IOCipher and CacheWord
Posted on September 26, 2014
| Hans-Christoph Steiner
We’ve been on a big kick recently, updating the newest members of our CipherKit family of frameworks: IOCipher and CacheWord. There also are is a little news about the original CipherKit framework: SQLCipher-for-Android.
IOCipher v0.2 IOCipher is a library for storing files in an encrypted virtual disk. It’s API is the exact same as java.io for working with files, and it does not need root access. That makes it the sibling of SQLCipher-for-Android, both are native Android APIs that wrap the SQLCipher database.
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ChatSecure 13.2: Important Beta!
Posted on August 5, 2014
| n8fr8
Today is the first public beta of ChatSecure v13.2, an important update of the user interface, networking code, and overall stability. We’ve spent the last six months tracking down crashes, memory leaks and performance issues, and have reached a stable, functional point which we want to share for public use. Reliability and simplicity our the goals, as we move towards v14 in the next few months.
This beta also features a new account setup wizard that we are eager for feedback on.
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Introducing TrustedIntents for Android
Posted on July 30, 2014
| Hans-Christoph Steiner
Following up on our research on secure Intent interactions, we are now announcing the first working version of the TrustedIntents library for Android. It provides methods for checking any Intent for whether the sending and receiving app matches a specified set of trusted app providers. It does this by “pinning” to the signing certificate of the APKs. The developer includes this “pin” in the app, which includes the signing certificate to trust, then TrustedIntents checks Intents against the configured certificate pins.
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New Official Guardian Project app repo for FDroid!
Posted on June 30, 2014
| Hans-Christoph Steiner
We now have an official FDroid app repository that is available via three separate methods, to guarantee access to a trusted distribution channel throughout the world! To start with, you must have FDroid installed. Right now, I recommend using the latest test release since it has support for Tor and .onion addresses (earlier versions should work for non-onion addresses):
https://f-droid.org/repo/org.fdroid.fdroid_710.apk
In order to add this repo to your FDroid config, you can either click directly on these links on your devices and FDroid will recognize them, or you can click on them on your desktop, and you will be presented with a QR Code to scan.
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Our first deterministic build: Lil’ Debi 0.4.7
Posted on June 9, 2014
| Hans-Christoph Steiner
We just released Lil’ Debi 0.4.7 into the Play Store and f-droid.org. It is not really different than the 0.4.6 release except in has a new, important property: the APK contents can be reproduced on other machines to the extent that the APK signature can be swapped between the official build and builds that other people have made from source, and this will still be installable. This is known as a “deterministic build” or “reproducible build”: the build process is deterministic, meaning it runs the same way each time, and that results in an APK that is reproducible by others using only the source code.
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Tweaking HTTPS for Better Security
Posted on February 12, 2014
| Hans-Christoph Steiner
The HTTPS protocol is based on TLS and SSL, which are standard ways to negotiate encrypted connections. There is a lot of complexity in the protocols and lots of config options, but luckily most of the config options can be ignored since the defaults are fine. But there are some things worth tweaking to ensure that as many connections as possible are using reliable encryption ciphers while providing forward secrecy. A connection with forward secrecy provides protection to past transactions even if the server’s HTTPS private key/certificate is stolen or compromised.
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Keys, signatures, certificates, verifications, etc. What are all these for?
Posted on December 12, 2013
| Hans-Christoph Steiner
For the past two years, we have been thinking about how to make it easier for anyone to achieve private communications. One particular focus has been on the “security tokens” that are required to make private communications systems work. This research area is called internally Portable Shared Security Tokens aka PSST. All of the privacy tools that we are working on require “keys” and “signatures”, to use the language of cryptography, and these are the core of what “security tokens” are.
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Getting keys into your keyring with Gnu Privacy Guard for Android
Posted on December 6, 2013
| Hans-Christoph Steiner
Now that you can have a full GnuPG on your Android device with Gnu Privacy Guard for Android, the next step is getting keys you need onto your device and included in Gnu Privacy Guard. We have tried to make it as easy as possible without compromising privacy, and have implemented a few approaches, while working on others. There are a few ways to get this done right now.
Gnu Privacy Guard registered itself with Android as a handler of all the standard OpenPGP MIME types (application/pgp-keys, application/pgp-encrypted, application/pgp-signature), as well as all of the OpenPGP and GnuPG file extensions (.
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Issues when distributing software
Posted on October 31, 2013
| Hans-Christoph Steiner
There is currently a discussion underway on the Debian-security list about adding TLS and Tor functionality to the official repositories (repos) of Debian packages that is highlighting how we need to update how we think about the risks when distributing software. Mostly, we are used to thinking about making sure that the software that the user is installing is the same exact software that has been posted for distribution. This is generally handled by signing the software package, then verifying that signature on the user’s machine.
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Keeping data private means it must be truly deletable!
Posted on August 23, 2013
| Hans-Christoph Steiner
There are lots of apps these days that promise to keep your data secure, and even some that promise to wipe away private information mere seconds or minutes after it has been received. It is one thing to keep data out of view from people you don’t want seeing it, it is also important to be able to truly delete information. Unfortunately computers make it very difficult to make data truly disappear.
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Our Newest App: PixelKnot
Posted on July 18, 2013
| mark
Have you ever hidden in plain sight? Worn camouflage in the woods or an invisibility cloak in a narrow crooked alley? It’s really hard to do properly. We’re hoping that all changes with PixelKnot.
PixelKnot is an app for hiding secret messages in pictures. Sort of like invisible ink on the back of a painting, updated to the present. The ancient art known as steganography, now updated for the 21st century and requiring a more rigorous set of safety standards.
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A Weather Report On Security
Posted on June 14, 2013
| mark
How’s the weather outside? Sunny with a chance of IP blocking.
We recently launched a new initiative we’re calling: The Weather Repo. The goal of the project is for organizations to have a more accurate method of understanding whether the apps they’re using are “safe”. It’s hard to know whether apps that claim to be secure really are. Have they been vetted by a third party? Are there existing case studies?
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