Pocket informers: Privacy problems with portable communication - - PowerPoint PPT Presentation

Pocket informers: Privacy problems with portable communication objects

Mathieu Cunche

mathieu.cunche@inria.fr @Cunchem

INSA-Lyon CITI, Inria Privatics

10th European e-Accessibility Forum e-Accessibility in a connected world 30 May 2016, Paris

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Wi-Fi networking

Wi-Fi specified by IEEE 802.11 standard Information transmitted in frames over the radio channels

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802.11 frame

Address fields contain MAC addresses (src., dest., ...) MAC address: a unique identifier allocated to a network interface

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Wi-Fi service discovery I

Discover surrounding APs and Networks

Passive mode: Wi-Fi Beacons Active mode: Probe requests and Probe Responses Probe requests contain an SSID field to specify the searched network

Active is less costly in energy

Preferred mode for mobile devices

Passive Active

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Active service discovery

Probing Frequency: several times per minutes Information available in cleartext (headers are not encrypted)

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Personal information from SSIDs

SSIDs: name of the previously connected networks

Stored in the Configured Network List (CNL) Observed up to 80 configured networks !

SSIDs: personal data Travel history GPS coordinates Social links

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Wi-Fi tracking

Wi-Fi enabled smartphone: portable personal beacon

Broadcast a unique ID (MAC addr.) Range: several 10s meters

Wi-Fi tracking system1

Set of sensors collect Wi-Fi signal Detect and track Wi-Fi devices and their owners

• 1A. B. M. Musa and Jakob Eriksson. “Tracking unmodified smartphones using Wi-Fi

monitors”. In: Proceedings of the 10th ACM Conference on Embedded Network Sensor

• Systems. 2012.
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Wi-Fi tracking: applications I

Road monitoring

Wi-Fi sensor deployed along the road Measure traffic density Detect traffic jam Estimate point-to-point travel time

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Wi-Fi tracking: applications II

Shops & shopping center monitoring

2

Physical analytics: Frequency and length of visit, number of visitor,

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Wi-Fi tracking: applications III

Profiling & Targeted advertisement Example: London’s Wi-Fi bins

Detect individuals via Wi-Fi Targeted advertisement displayed on screen Based on a user profile: consuming habits, gender, ...

2Source: Euclid Analytics

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Wi-Fi tracking: privacy

Privacy concerns of civil society ”People have a fundamental right to privacy, and I think neglecting to ask consumers for their permission to track them violates that right” – Senator Al Franken Regulation of data protection agencies

CNIL decision on Fidz’up/JCDecaux initiative (La Defense)

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Wi-Fi tracking: privacy

The MAC address a 48 bits identifier The MAC address is a personal information

Unique ID & Personally identifiable information Easy to obtain the MAC addr. of an individual Collected by mobile applications along with other personal information (phone number, email, name, ...)

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Countermeasures

Use a random MAC address

Periodically change MAC address to a random value3

Currently being deployed in major Operating Systems

iOS8, Windows10, Android, Linux ...

Limitations of random MAC addr.

Tracking may still be possible: fingerprinting4 Using MAC address may disrupt networks

3Marco Gruteser and Dirk Grunwald. “Enhancing location privacy in wireless LAN through

disposable interface identifiers: a quantitative analysis”. In: Mobile Networks and Applications 10.3 (2005), pp. 315–325.

4Mathy Vanhoef et al. “Why MAC Address Randomization is not Enough: An Analysis of

Wi-Fi Network Discovery Mechanisms”. In: ACM AsiaCCS. Xi’an, China, May 2016.

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Countermeasures

Geofencing

Wi-Fi only activated in trusted places (home, office, ...) Apps: Wi-Fi Matic5 and AVG Privacy Fix6 (only for Android)

5https://play.google.com/store/apps/details?id=org.cprados.wificellmanager 6https://play.google.com/store/apps/details?id=com.avg.privacyfix

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The case of Bluetooth

Bluetooth is a short range radio technology

Found in many connected objects Also use a MAC address as radio identifier Potentially expose to privacy issues

(In)Visibility mode

Device don’t advertise their presence

Random radio identifier (since v4.0)7

Prevent tracking Fully integrated in the protocol: do not disrupt network functionnalities

7http://blog.bluetooth.com/bluetooth-technology-protecting-your-privacy/

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Role of the industry and standardisation bodies

Technological legacy

Wi-Fi designed in late 1990’s Unexpected applications: Wi-Fi in every pocket Security (confidentiality) was considered, but not privacy

Privacy is now a real concern for the industry

Privacy preserving features deployed in major systems Dedicated working groups at IETF and IEEE

Privacy by design approach

Privacy needs to be considered early in the design process Too late for current technologies like Wi-Fi

Patches and temporary fixes

Ex: Random MAC address being deployed by major OSs (iOS, Android, Windows, ...)

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Conclusion

Privacy is not restrained to applications (Web, Apps, ...)

Radio technologies can also leak personal information

Privacy needs to be considered early in the design process Imagination of trackers not to be underestimated

Motivated by commercial applications ... or population surveillance & control

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Thank you

Figure : Artist’s interpretation8.

8credit P. Treimany

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