encryption

I am looking for free data encryption app. So far my searches have turned up articles that describe non-free apps and network/email encryption. All I want is a easy to use data encryption app.

One of my friends had his phone robbed. Since he's unemployed and I wanted a new phone, I decided to give my phone to him and buy a new one. The problem here is: this friend of mine is really good with tech, and I have bank passwords, important and private conversations, images etc on this...

So i woke up one morning to open facebook and it gave me a report like it wasnt working but then everything did that Chrome, Handouts, etc. so i restarted my phone thinking it would fix then i got the Encryption screen. I already wipe data/Factory reset wipe cache partition md5 check as well...