RFC 2623:NFS Version 2 and Version 3 Security Issu...
RFC-Ref

password


Click on the red underlined text to get to the source

... operating system, the user may have knowledge of the root user password. And even if he does not have that knowledge, with physical access to the desk-top machine, root ...
... encrypted, a malicious user must know another user's network password or private key to masquerade as that user. ...
... encrypted so that masquerading as a server requires knowing a network password. ...



Google
Web
RFC-Ref