Whisper Systems, a company that provides mobile security products for Android, has been acquired by Twitter. The company’s products, which aim to enterprise-ify phones and tablets, include WhisperCore, WhisperMonitor, Flashback, RedPhone and TextSecure.

WhisperCore integrates with Android to provide disk encryption, network security tools, encrypted backup, selective permissions, and basic platform management tools. WhisperMonitor works with WhisperCore to provide a firewall. Flashback stores encrypted backups of devices in the cloud. RedPhone provides end-to-end call encryption, and TextSecure is for encrypted texting.

Twitter’s Ryan Sarver tweeted:

In a message on the company blog, Whisper Systems says:

We started Whisper Systems with the goal of improving security and privacy for mobile devices. We were attracted to this not only because we saw it as an opportunity to reinvent the security solutions that never really worked in the PC environment to begin with, but also because the stakes are much higher — due to the nature of mobile devices themselves — and we didn’t like the way that things were looking.

Now that we’re joining Twitter, we’re looking forward to bringing our technology and our expertise into Twitter’s products and services.

Whisper Systems’ software will remain available for users, but the products will be taken offline temporarily during the transition period.

Terms of the acquisition have not been disclosed.