Over at A Few Thoughts on Cryptographic Engineering, Matthew Green has a useful review of some secure communications apps. He looks at
- Cryptocat
- Silent Circle
- RedPhone
- Wickr
from the standpoint of code quality, encryption protocols, and ease of use.
Interestingly, Green examines the apps from the point of view of “should I use this application to fight an oppressive regime?” It’s not a frivolous question. Citizens fighting and journalists covering those oppressive regimes need to communicate and if their communications are not secure, their lives and the lives of others could be at risk. It also explains his emphasis on ease of use. Most revolutionists and journalists are not technically sophisticated and are especially prone to using crypto applications in a non-secure way.
If you’re looking for a way to keep your communications private—even if you’re not trying to overthrow a government—you should take a look at Green’s post. In addition to providing a review of some of the leading applications in the field, it shows you what sort of things to look for and what sort of questions to ask.
If you like his post, you might also enjoy this video of Green delivering a talk on the current state of cryptography. If you depend on cryptography in your day-to-day activities you will doubtless find it enlightening (and disturbing).