IOCipher is the antidote to “Man-in-the-Disk” attack

Recently, at DEFCON 2018, researchers at Check Point announced a new kind of attack made possible by the way many Android apps are implemented. In summary, developers use the shared external storage space in an unsafe manner, by not taking into consideration that other apps also have read and write access to the same space. A malicious app can modify data used by another app, as a vector for compromising that app, causing it to be compromised or crash. [Read More]

CipherKit reproducible builds

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). [Read More]

First working test of IOCipher for Obj-C

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! [Read More]

CipherKit updates: IOCipher and CacheWord

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. [Read More]

Keeping data private means it must be truly deletable!

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. [Read More]

IOCipher beta: easy encrypted file storage for your Android app

At long last, we are proud to announce the first beta release of IOCipher, an easy framework for providing virtual encrypted disks for Android apps. does not require root or any special permissions at all the API is a drop-in replacement for the standard java.io.File API, so if you have ever worked with files in Java, you already know how to use IOCipher works easiest in an app that stores all files in IOCipher, but using standard java. [Read More]

report on IOCipher beta dev sprint

We are just wrapping up an intensive dev sprint on IOCipher in order to get the first real beta release out, and it has been a wonderfully productive session on many levels! Before we started this, we had a proof-of-concept project that was crashy and ridiculously slow. We’re talking crashes every 100 or so transactions and 9 minutes to write 2 megs. Abel and I were plodding thru the bugs, trying to find the motivation to dive into the hard problems in the guts of some of the more arcane parts of the code. [Read More]

Sometimes the best solution is a library, not an app

Our general approach to software development starts with surveying existing solutions that are available and in use, to see if there is already enough of an ecosystem or whether we need to seed that. When there is already an adundance of tools and apps out there, we work to find the good ones, provide feedback and auditing, and then build apps and tools to fill in any gaps. For example, this was our approach in the Open Secure Telephony Network. [Read More]