  Despite the attempts of well-designed anonymous communication tools to
protect users from tracking or identification, flaws in surrounding software
(such as web browsers) and mistakes in configuration may leak the user's
identity. We introduce Nymix, an anonymity-centric operating system
architecture designed "top-to-bottom" to strengthen identity- and
tracking-protection. Nymix's core contribution is OS support for nym-browsing:
independent, parallel, and ephemeral web sessions. Each web session, or
pseudonym, runs in a unique virtual machine (VM) instance evolving from a
common base state with support for long-lived sessions which can be anonymously
stored to the cloud, avoiding de-anonymization despite potential confiscation
or theft. Nymix allows a user to safely browse the Web using various different
transports simultaneously through a pluggable communication model that supports
Tor, Dissent, and a private browsing mode. In evaluations, Nymix consumes 600
MB per nymbox and loads within 15 to 25 seconds.
