Fields within a document can be securely encrypted by the SDK, to support FIPS-140-2 compliance.
Field Level Encryption is normally carried out at a higher level than libcouchbase (LCB). It is available in the LCB 'wrapper' SDKs: Node.js and Python. It will be available in a later release of the other LCB 'wrapper' SDKs, PHP. It will not be available in LCB.