PlugDB: portable protection against prying eyes

Imagine that you have been entrusted with sensitive data, say
corporate, governmental, or medical. Periodically you want to link that
data with public data.
If you do this naively in an internet cafe, at a customer site,
or even on your laptop, spyware could easily steal your data.
PlugDB offers you an alternative.
You carry your sensitive data with you on a USB key.
When you plug in your key, you want to link your
private data with the public data without revealing
the private data. PlugDB ensures that
the only information flow
is towards your key (though your key has a small screen
or camera for you to see output).
This demo illustrates the behavior of a user in possession of
PlugDB who plugs the USB key into a modern personal
computer, shows the novel
query plans used when mixing public and private data on
highly asynchronous devices (PC and key),
then compares the performance of the mixed public and private
queries using PlugDB with equivalent queries on the
personal computer. 

The user will see four screens:

1. Public -- shows the schema seen when the USB key is not plugged in
Demo attendees will be able to write queries against that schema.

2. Private -- shows the schema seen when the USB key is plugged in.
This is a superset of the public schema.
Demo attendees will be able to write queries against that schema.

3. Query plan -- a series of animated drawings showing private-public
queries in the course of execution.

4. Bar chart -- for each query, shows the time to execute a public-private
query on the PC alone (if the data were there)
vs. the time to execute the public-private query using our query
processing methods.


What the demo attendees will learn:

how to specify private data as a database administrator

how to query public and private data (the surprise is that we use
standard sql, 
though currently restricted to select-project-join-aggregate queries)

the unique query processing methods used

the experience of having entirely private data