K-9 Mail is an email client focused on making it easy to chew through large volumes of email. It supports advanced features, such as multiple identities, detailed notification settings, and privacy features to hide metadata. In combination with OpenKeychain, it implements the Autocrypt standard. This allows convenient end-to-end encryption of emails. In addition, OpenKeychain provides advanced key management capabilities for syncing and backing up keys.
OpenKeychain was started in 2012 by Dr. Dominik Schürmann, one of the founders of Cotech. Since its integration with K-9 Mail, it attracted a community of active developers, cryptographers and scientists. Several research papers [Rubinov et al., Dechand et al., Schürmann et al.] have been published and an audit confirmed its security [Cure53].
We all share the vision of building a more secure Internet to protect civil liberties and business interests. We do this by actively participating in the email security community (on OpenPGP conferences, summits and scientific conferences, such as Usenix Security, PETS). To make email encryption easier, we started writing the Autocrypt specification with other email client developers.
Today, K-9 Mail + OpenKeychain is the one of the most secure solutions for email communication.
“OpenKeychain happens to be one of the easiest encryption tools available for Android.” - TechRepublic
“[…] none of the spotted issues were considered to be of a critical severity in terms of security implications. The latter is a significant and impressive result for an app of this complexity and relevance.” - Cure53 Security Audit
While there is no guaranteed response time SLA for Cotech, we strive to respond quickly to priority requests, usually within one business day.