K.U.Leuven

George Danezis1 and Alfredo Rial1,2

Privacy-Preserving Smart Metering

1Microsoft Research Cambridge2KULeuven ESAT/SCD/COSIC – IBBT, Belgium

WPES17 / 10 / 2011

Privacy-preserving Smart Metering 17 October 2011

17 October 2011

• Introduction to smart metering and privacy• System Model• Our Protocol

o Constructiono Implementation

• Conclusion

Index

2Privacy-preserving Smart Metering

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1 – INTRODUCTION

3Privacy-preserving Smart Metering

http://overview.ge-energy.com/energyservices/index.jsp

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4Privacy-preserving Smart Metering

Smart Grid

Power generation

Power transmission Power distribution

Industrial Customers

Residential Customers

Commercial Customers

Data communication

Electricity trasmission

New communication channels!

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Smart Meter

5Privacy-preserving Smart Metering

• Reports fine-grained consumption data• Receives commands: switch-off, change to prepaid mode, etc.• Interaction via a user-friendly interface

http://legalplanet.wordpress.com/2010/08/20/smart-meters-and-smart-regulation/ http://www.treehugger.com/files/2010/07/

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ADVANTAGES

6Privacy-preserving Smart Metering

• Efficient Delivery

• Prevention of Outages

• Self-healing grid

http://www.fresnobee.com/2010/02/26/1838492/editorial-cartoon-pges-smart-meters.html

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ADVANTAGES

7Privacy-preserving Smart Metering

http://www.boost-energy.com/boost/davidblog.html

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ADVANTAGES

8Privacy-preserving Smart Metering

ELECTRICITY SAVING VIA MATCHING GENERATION AND DEMAND

http://blog.news-record.com/opinion/letters/archives/2007/10/cartoon_took_cheap_shot_at_ove.shtml

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ADVANTAGES

9Privacy-preserving Smart Metering

HELPUSERSSAVE

ENERGYhttp://www.greenbang.com/jurdy-hair-raising-energy-consumption_14998.html

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• USA: Energy Independence and Security Act of 2007o American Recovery and Reinvestment Act (2009, $4.5bn)

• EU: Directive 2009/72/EC• UK: deployment of 47 million smart meters by 2020

DEPLOYMENT

10Privacy-preserving Smart Metering

http://www.ci.royal-oak.mi.us/portal/book/export/html/1751 http://www.treehugger.com/files/2010/05/obama-finally-starts-talking-clean-energy-wake-gulf-spill.php

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2 - PRIVACY THREATS

11Privacy-preserving Smart Metering

http://turn.org/article.php?id=875

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Fine-Grained Consumption Data

12Privacy-preserving Smart Metering

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Privacy Concerns

13Privacy-preserving Smart Metering

Personal Information can be inferred:• When you are at

home• Which appliances

you use• When you eat• Whether you

arrive late to work

http://www.zazzle.co.uk/obamas_smart_metre_is_communism_tshirt-235996664492570554

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Privacy Concerns

14Privacy-preserving Smart Metering

http://forcechange.com/2009/02/10/google-jumps-into-the-smart-meter-industry-and-debate/

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Social Pressure

15Privacy-preserving Smart Metering

http://www.indybay.org/newsitems/2010/08/26/18656872.php

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Consequences

16Privacy-preserving Smart Metering

“The Dutch First Chamber considers the mandatory nature of smart metering as an unacceptable infringement of citizens’ privacy and security”

http://turn.org/article.php?id=1154

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3 – SYSTEM MODEL

17Privacy-preserving Smart Metering

http://antennagroup.com/transmissions/tag/conferences/

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ENTITIES

18Privacy-preserving Smart Metering

Provider (P) User (U) Meter (M)

 

 

 

http://news.bbc.co.uk/2/hi/8042716.stm

http://www.daylife.com/photo/04SSd1bgHS0Tp

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• P is assured that U reports correct fee

• P does not learn (cons, other)

• P cannot claim U must pay fee’

SECURITY REQUIREMENTS

19Privacy-preserving Smart Metering

http://www.inkity.com/catalog/product/2/2077/Shaking-On-Money-Deal.html

http://apcit.blogspot.com/

http://www.billboardmama.com/recording-connection-scam-p-1017.html

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• M should be tamper-resistant

• No direct uplink from M to P

ASSUMPTIONS

20Privacy-preserving Smart Metering

http://www.smartplanet.com/business/blog/smart-takes/report-smart-meters-have-security-holes-that-could-allow-hackers-access-to-grid/5532/

http://trac.cyberduck.ch/wiki/help/en/howto/googledocs

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M, U, P interact in five phases:• Setup & Initialization• Consumption Phase• Payment Phase• Policies

4 – Our Protocol

21Privacy-preserving Smart Metering

http://www.imetertechnology.com/

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Setup Phase

22Privacy-preserving Smart Metering

Compute key pair

Compute key pair Compute key pair

Compute commitment params

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Initialization Phase

23Privacy-preserving Smart Metering

Choose pricing policy

Signs pricing policy

Υ 𝑠={𝜎 }Υ 𝑠

Verify signed policy

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Consumption Phase

24Privacy-preserving Smart Metering

Read

Commits to consumption and other

Signs commitments

(𝜎 ,𝑑𝑀 ,𝑐𝑜𝑛𝑠 ,𝑜𝑝𝑒𝑛𝑐𝑜𝑛𝑠 , h𝑜𝑡 𝑒𝑟 ,𝑜𝑝𝑒𝑛 h𝑜𝑡 𝑒𝑟 )Verifies commitment openings

Verifies signature

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Payment Phase (I)

Compute price

Commit to price

Proof knowledge of signature that bind consumption and price

For all tuples output by M

Privacy-preserving Smart Metering 25

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Payment Phase (II)

26Privacy-preserving Smart Metering 26Privacy-preserving Smart Metering

Aggregate prices and openings

Compose a payment message

Sign payment message (𝑚 ,𝑠𝑚) Verify Signature

Verify proofs

Aggregate commitments to price

Verify Opening of

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Pricing Policies

27Privacy-preserving Smart Metering

Consumption

Pric

e

Linear PolicyDiscrete Policy

Pric

e

Consumption

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Pricing Policies

28Privacy-preserving Smart Metering

Interval Policy

Pric

e

Consumption Consumption

Cumulative Policy

Pric

e/C

onsu

ptio

n

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Pricing Policies

29Privacy-preserving Smart Metering

Pric

e

Consumption

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• Secure when M and P do not collude.oModification possible to ensure security when

they collude, albeit efficiency decreases by a factor of

• Very Efficient construction when choice of signature in the policy does not depend on and is linear.oNIPK are not needed.o Ideal for electricity metering

Remarks

30Privacy-preserving Smart Metering

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• It does not require anonymous channels or anonymized databases

• It does not require interaction among users• Minimises Trusted Computing Base• It does not require trusted parties• It is efficient enough for practical applications• It supports a wide variety of pricing policies• It permits selective disclosure of private data

Advantages

31Privacy-preserving Smart Metering

http://www.frikipedia.es/friki/An%C3%B3nimo

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Evaluation

32Privacy-preserving Smart Metering

32 Bit 64 Bit

Full-fledgedConstruction

EfficientConstruction

Full-fledgedConstruction

EfficientConstruction

Consumption Phase

31.4/s 31.4/s 171.209/s 171.209/s

Compute Payment

1.5/s 26780.6/s 20.1444/s 298295/s

Verify Payment

2.2/s 3711.02/s 91.3977/s 16345/s

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• Privacy-Preserving smart metering system:o Allows reporting fee without disclosing consumptiono Minimizes TCBo Does not require anonymity or MPCo Supports wide variety of pricing policieso Efficient Implementation

• Other applications: o Pay-as-you-drive car insuranceo road tollingo cloud computing billing

Conclusions

33Privacy-preserving Smart Metering

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Questions

34Privacy-preserving Smart Metering

http://blogs.courant.com/bob_englehart/2008/07/july-10-2008.html