Flock Android App Encrypts Contacts, Calendar Syncs

Credit: Whisper Systems.

(Image credit: Whisper Systems.)

A doctor's appointment at 10 a.m. The places you'll be, and when you'll be there. The email addresses and telephone numbers of dozens, maybe hundreds, of your friends and family members.

The calendar and contacts list on your phone are comprised of highly personal, sometimes dangerously sensitive, information. That's why we like the sound of a new Android app, called Flock, that adds an extra layer of encryption to your synced data.

Flock, made by San Francisco-based Open Whisper Systems, meshes with Android's already-existing calendar and contacts apps. Available from yesterday (July 21)  for Android phones running Android 4.1 and up, Flock costs $5 per year and comes with a 30-day free trial.

MORE: How to Encrypt Your Android Phone or Tablet

According to Open Whisper Systems, Flock encrypts the contacts and calendar data before it leaves the device, so it's always encrypted between the  device and the sync server.

"We never see your password, and we can't be compelled to hand over the keys to your data," Open Whisper Systems said in a statement.

Flock can also be used to set up an entirely separate data backup server that you host yourself. Whether you want to continue using Android's built-in calendar and contact tools, or you'd like a new one under your own control, Flock has something for you.

The full extent of Flock's encryption capabilities isn't clear. For example, if the sync data is encrypted when it leaves the user's device, can the data be synced with any other device linked to the same Google account, such as a desktop Web browser? What if users were to add contact or calendar info to their Google account via a desktop Web browser, then synced their Android phones? Would the information traveling toward the Android device be encrypted?

We've reached out to both Open Whisper Systems and Google for clarification and will update this story if we get answers.

Flock is open-source; anyone can examine and improve upon the code on the company's GitHub page. Don't worry -- knowing the encryption algorithms and how they're implemented doesn't undermine the security, and some experts assert that open-source software is more secure than proprietary software due to greater scrutiny and quicker patching of discovered flaws. 

Open Whisper Systems also makes TextSecure, an app that adds encryption to an Android phone's SMS and MMS text messaging system, and RedPhone, which offers encrypted telephone calls.

Email jscharr@tomsguide.com or follow her @JillScharr and Google+.  Follow us @TomsGuide, on Facebook and on Google+.

Jill Scharr is a creative writer and narrative designer in the videogame industry. She's currently Project Lead Writer at the games studio Harebrained Schemes, and has also worked at Bungie. Prior to that she worked as a Staff Writer for Tom's Guide, covering video games, online security, 3D printing and tech innovation among many subjects.