anonymity; using an assumed name
concealment (esp. of wrongdoings or criminals); sheltering; harboring
anonymization (of data); anonymisation
concealment; shelter; harboring; harbouring
(crime of) harboring a fugitive (harbouring)
anonymous partnership; silent partnership; anonymous association
request to remain anonymous; name withheld by request
privilege (e.g. "attorney-client privilege")
diving under cover and hiding
ad hoc group formed to commit crimes
hiding one's abilites (by living in concealment)