Privacy in the Age of Ubiquitous Computing

Jason I. Hong

Scott Lederer

Jennifer Ng

Anind K. Dey

James A. Landay

G r o u p f o rUser Interface Research

University of CaliforniaBerkeley

Mar 05 2004 2

The Origins of Ubiquitous Computing

What’s wrong with Personal Computers?– Too complex and hard to use– Too demanding of attention– Too isolating from other people– Too dominating of our desktops and our lives

Ubiquitous Computing Project at Xerox PARC– Advances in wireless networking, sensors, devices– Observations of how people use tools in practice– Make computers a natural part of everyday

interactions

Mar 05 2004 3

The Origins of Ubiquitous Computing

Mar 05 2004 4

Emerging Examples of Ubicomp

Never Get Lost

Find Friends

Emergency Response

Mar 05 2004 5

“But What About My Privacy?”

Never Get Lost– You walk past a restaurant and your cellphone rings with the

specials of the day

Find Friends– “Family is already very close to you, so if they’re checking up

on you…sort of already smothering and this is one step further.”

– “[It] could tell when you were in the bathroom, when you left the unit, and how long and where you ate your lunch. EXACTLY what you are afraid of.”

Emergency Response– “I don’t see how a government or an organization will not

come up with an excuse to use [location info] for another purpose.”

Flood of Location-Based Spam

Never Hide From Friends and Co-Workers

Constant Surveillance

Mar 05 2004 6

Our Research in Ubicomp Privacy

Fundamental Tension– Ubiquitous Computing can be used for great benefit– Ubiquitous Computing can be used for great harm– Privacy may be greatest barrier to long-term success

Our approach– What are the privacy concerns in ubicomp?– How can we design better user interfaces?– Are there better ways of building privacy-sensitive apps?

Privacy is an area easy to make mistakes in– Will discuss lessons learned throughout

Mar 05 2004 7

What is Privacy?

Lots of perspectives on privacy– US Constitution, UN Decl. Human Rights, Hippocratic Oath– Influenced by Legal, Market, Social, and Technical forces

Privacy is not just Orwell– From “Big Brother” to “Little Sisters”– Media sensationalization of worst-case scenarios

Privacy is not just computer security– Adversaries? Friends, family, co-workers, acquaintances– Anonymity? Friends already know your identity– Secrecy? We share personal info with friends all the

time– Damage? Risk may be undesired social obligations

We are approaching privacy from an HCI perspective

Mar 05 2004 8

An HCI Perspective on Privacy

“The problem, while often couched in terms of privacy, is really one of control. If the computational system is invisible as well as extensive, it becomes hard to know:

– what is controlling what– what is connected to what– where information is flowing– how it is being used– what is broken (vs what is working correctly)”

The Origins of Ubiquitous Computing Research at PARC in the Late 1980s

Weiser, Gold, Brown

Make it easy to share: • the right information• with the right people (or service) • at the right time

Mar 05 2004 9

What are End-User Privacy Needs?

Lots of speculation about privacy, little data out there

Analyzed survey of 130 people on ubicomp privacy prefs

Analyzed nurse message board on locator systems– http://allnurses.com

Examined papers describing usage of ubicomp systems

Examined existing and proposed privacy protection laws– EU Directive, Location Privacy Act 2001, Wireless Privacy Act 2004

Interviewed 20 people on various location-based services– Did not mention the word “privacy” unless they did first

Mar 05 2004 10

End-User Privacy Needs

Value proposition

Simple and appropriate control and feedback

Plausible deniability

Limited retention of data

Decentralized architectures

Special exceptions for emergencies

Alice’sLocation

Bob’sLocation

Mar 05 2004 11

How to Design for Privacy?

What are good privacy-sensitive user interfaces?– Knowing what is needed does not say how to do it well

Mar 05 2004 12

Five Pitfalls for Designers

Understanding

Obscuring potential information flow

Obscuring actual information flow

Action

Configuration over action

Lacking coarse-grained control

Inhibiting established practices

Mar 05 2004 13

#1 – Obscuring Potential Flow

Users can make informed use of a system only when they understand the scope of its privacy implications

Mar 05 2004 14

#2 – Obscuring Actual Flow

Users should understand what information is being disclosed to whom

Who is querying my location?How often?

Requestor informed of disclosureRequestee sees each request

Mar 05 2004 15

#3 – Configuration Over Action

Designs should not require excessive configuration to manage privacy– “Right” configuration hard to predict in advance– Make privacy a natural part of the interaction flow

Mar 05 2004 16

#4 – Lacking Coarse-Grain Control

Designs should not forego an obvious, top-level mechanism for halting and resuming disclosure

“[T]raveling employees may want their bosses to be able to locate them during the day but not after 5 p.m. Others may want to receive coupons from coffee shops before 9 a.m. on weekdays but not on weekends when they sleep in. Some may want their friends alerted only when they are within one mile, but not 10 miles.”

Protecting the Cellphone User's Right to Hide

NYTimes Feb 5 2004

Did I set it right?How do I know?

Mar 05 2004 17

#5 – Inhibiting Established Practices

Designs should not inhibit users from transferring established social practices to emerging technologiesRather than getting an immediate ring, an answering machine comes on the line and says, "Lee has been motionless in a dim place with high ambient sound for the last 45 minutes. Continue with call or leave a message."

1. University and Ramona2. Palo Alto3. Custom…

9. Ignore for now

Mar 05 2004 18

How to Build Applications Better?

Develop a toolkit to make it easier to build privacy-sensitive ubicomp apps– Prevent – Strong guarantees on your personal data– Avoid – Better user interfaces for managing privacy– Detect – Finding over-monitoring or accidental

disclosures– Need all three for effective systems

Key architectural points of Context Fabric– Locality– InfoSpace Diary– Access Descriptions– Privacy Tags

Mar 05 2004 19

Locality

Keep personal data “close” to end-users– Move from centralized systems to decentralized ones– Capture, store, and process personal data on my

computer

PlaceLab

AB

C

Add more placelab guts hereAdd slide on MiniGis here as well

What are the alternatives here?Centralization was an issue early on

Also talked to a lawyer about this (Deidre)Closer data is to you, more legal protection

–Works indoors and in urban canyons

–No special equipment

–Privacy-sensitive–Rides the WiFi wave

Mar 05 2004 20

PlaceLab

~52000 Nodes

(3Megs)

Mar 05 2004 21

PlaceLab

~500 Nodes

Mar 05 2004 22

Locality

MiniGis Server for processing location locally

Country Name = United StatesRegion Name = CaliforniaCity Name = BerkeleyZIP Code = 94709Place Name = Soda HallLat Lon = 37.8756, -122.25711

Mar 05 2004 23

Locality

MiniGis Server data sources

USGS State Gazetteer– Names in USA– 2m records ~650 megs– States, Cities, Places

“Places” hardest to get– Airports & schools useful, “hammocks”, “lava”,

“quicksand” less so– 2 undergrads scouring Berkeley– Research opportunity here in open, distributed naming of

places

GEOnet Names Server– Names outside USA– 5.5m records ~700megs– Regions, Cities, Places

Mar 05 2004 24

InfoSpace Diary

InfoSpace stores your personal information– Static info, like name and phone#– Dynamic info, like current location and activity

Runs on your personal device or on a trusted service– Local sources (ex. PlaceLab) can update dynamic info– Can choose to expose different parts to different people &

services– Can also see who can see what about you

Describe guts of InfoSpace moreDescribe Tuples more

Operators too?

Mar 05 2004 25

Confab Architecture

InfoSpace

Diary

InfoSpace

Diary

LocNamePlaceLab

Tourguide

Find Friend

MiniGis

How to control when and how much personal info is disclosed?

Request

Mar 05 2004 26

Access Notifications

One possibility:

“[T]raveling employees may want their bosses to be able to locate them during the day but not after 5 p.m. Others may want to receive coupons from coffee shops before 9 a.m. on weekdays but not on weekends when they sleep in. Some may want their friends alerted only when they are within one mile, but not 10 miles.”

Problems:– People are not good at defining rules beforehand– Tradeoff between fine-grained control and

understandability

Mar 05 2004 27

Observations on Setting Preferences

Who is requesting information is most important factor– “Either I trust someone with my information or I don't –

it doesn't depend on where I am.”

Time is an essential aspect for maintaining control– Access described in terms of “always”, “never”, or “work

hours”– “Work people can know my information during work hours.

Home/SO people can know my information always.”

Can set prefs before, during, or after a request– Before case can lead to configuration pitfall– During case easier to understand, but can overwhelm– After case easy to setup, but can lead to accidental

disclosures

Mar 05 2004 28

Access Notifications

Mar 05 2004 29

Access Notifications

Initial Evaluations– Tested with 4 people for understandability and

reactions– Location-enhanced messenger, tourguide, emergency

response

Mar 05 2004 30

Access Notifications

Initial Evaluations– Tested with 4 people for understandability and reactions– Location-enhanced messenger, tourguide, emergency

response

Results

– Distinction between Push vs Pull, Continuous vs Discrete

“Giving a GPS location once or twice does not provide enough information for an invasion of privacy… [but] if GPS location is shared every 2 seconds, there is a potential for an invasion of privacy.”

“No need for continuous update of location. Only in a race or a marathon (where staying on track is essential) would continuous update be helpful.”

Mar 05 2004 31

Access Notifications

PlaceBar

Continuous Discrete

Push ???

Pull Access Notifications

Mar 05 2004 32

Confab Architecture

InfoSpace

Diary

InfoSpace

Diary

LocNamePlaceLab

Tourguide

Find Friend

MiniGis

How to control what happens to your info onceit leaves your InfoSpace?

Access

AccessPull

Push

Mar 05 2004 33

Privacy Tags

Digital Rights Management for Privacy– Like adding note to email, “Please don’t forward”– Notify address - notify-

abc@cs.berkeley.edu– Time to live - 5 days– Max number of sightings - last 5 sightings of my

location

Libraries for making it easy for app developers

Mar 05 2004 34

Analysis

Prevent– Capture and process personal information locally– PlaceLab, MiniGis– Minimizes risk of mission creep (ex. SSNs)

Avoid– Interfaces for helping people make good decisions– Access Notifications / PlaceBar

Detect– Finding cases of over-monitoring– Access Notifications– Privacy Tags (processed on requestor’s side)

Mar 05 2004 35

Implementation

Confab, PlaceLab, MiniGis– Java 1.5, Tomcat Web Server, MySql, Jaxen XPath

Data– WiFi from wigle.net and undergrads– MiniGis from USGS, GeoNET, and undergrads– ~35 megs of data (30 megs of place data)

#Classes Lines of code

Confab 320 17000

PlaceLab 10 800

MiniGis 15 3000

Shared Libs

230 12000

Mar 05 2004 36

Putting it TogetherLemming Location-enhanced Messenger

Describe Rationale as to why location + messenger?

Show more gutsDescribe LOC

Mar 05 2004 37

Putting it TogetherBEARS Emergency Response Server

Field studies and interviews with firefighters [CHI2004]

Finding victims in a building– “You bet we’d definitely want that.”– “It would help to know what floor they are on.”

But emergencies are rare– How to balance privacy constraints with utility when

needed?

Mar 05 2004 38

Putting it TogetherBEARS Emergency Response Server

Trusted third party (MedicAlert++)

MedicAlert++MedicAlert++

Loc

“ABC”

“ABC”

On Emergency

Mar 05 2004 39

Requirements Check

Value proposition

Simple and appropriate control and feedback– Access Notifications (pull) and PlaceBar (push)

Plausible deniability– No action, “Ignore for now”, and “Never Allow” appear

same

Limited retention of data– Privacy Tags

Decentralized architectures– Capture and process information locally

Special exceptions for emergencies

Mar 05 2004 40

Contributions

Investigated ubicomp privacy from many perspectives– What are end-user needs? How to design? How to build?

Context Fabric architecture for privacy-aware apps– Prevent / Avoid / Detect– Suggests a way of architecting privacy-sensitive ubicomp

Services on devices, local processing, presentation to end-users

– Evaluation with two applications– Starting deployment of Lemming instant messenger

“Use technology correctly to enhance life. It is important that people have a choice in how much information can be disclosed. Then the technology is useful.”

Jason I. Hongjasonh@cs.berkeley.edu

http://guir.berkeley.edu/confab

G r o u p f o rUser Interface Research

University of CaliforniaBerkeley

Thanks to: DARPA Expeditions NSF ITR PARC Intel Fellowship Siebel Systems Fellowship

http://placelab.org