How to configure/setup data at rest encryption in Couchbase 5.1
See also the Field Level Encryption feature in Couchbase Server 5.5 Enterprise Edition (released last week).  From the docs there, you can select the platform you use.  Note this is not part of Couchbase Mobile (which as of this writing has encryption planned for the 2.1 Couchbase Lite release), but can obviously be used with mobile apps if crypto at the app server works for you.  There's also a specification for how the fields are handled if you wanted to handle it elsewhere.