In this paper, the authors presented design decisions taken during the construction of a framework for cryptographically secure communication on Android devices. The early prototypes still have many challenges to be overtaken, as follows. The use of cryptosystems for short signatures, elliptic curve cryptography and pairings-based cryptography are some of the improvements planned for the near future. Another challenge is to preserve usability in the presence of strong security concerns. Layered protections against common software vulnerabilities, such as secure deletion of sensitive information in flash memory, are planned in the roadmap.