b11d5318_ngs_Reference___Code42_Support__Details
[Consideration] Key storage for mobile devices CrashPlan mobile app only [Details] 
Encryption key is not stored on the device Secured key is sent from CrashPlan's server during the sign-in process Secured key is stored in the device's memory only while the CrashPlan mobile app is in the foreground and user is signed in
Security Settings Reference - Code42 Support