RFID Security and Privacy: A Research Survey. Vincent Naessens Studiedag Rabbit project

Transcription

1 RFID Security and Privacy: A Research Survey Vincent Naessens Studiedag Rabbit project

2 RFID Security and Privacy: A Research Survey 1. Introduction 2. Security and privacy problems 3. Basic RFID tags 4. Symmetric-key RFID tags 5. Conclusion

3 1. Introduction antenna RFID tag RFID = Radio Frequency IDentification RFID tag = device that is designed for wireless data transmission

4 1. Introduction Why is RFID technology so popular? - improves accuracy and timelines of information - dropping tag costs - vigorous RFID standardization unique identification automation fast scanning This is 100g bar of ABC brand chocolate, serial no type of object line-of-sight slow scanning This is 100g bar of ABC brand chocolate

5 1. Introduction identification on/off tags GSM/PDA s EPC

6 1. Introduction interaction with mobile phones shopping smart appliances s e i t i n u t por op medical compliance dangers

7 2. Security and privacy problems Privacy problems tracking and inventorying profiling _1 ber m u n _ al seri serial_number_2 serial _numbe r_3 personal information

8 2. Security and privacy problems Privacy problems serial_number_1 - scannable at any time - simple RFID reader - simple processing power - on/off switches -specialised telecommunication equipment (trusted service provider) - more processing power (~access control)

9 2. Security and privacy problems Privacy problems: cases euro banknotes libraries toll payment transponder human implantation for medical purposes passports

10 2. Security and privacy problems Privacy problems: read ranges 10cm nominal read range 50cm rogue scanning range 50 cm tag-to-reader eavesdropping range > 5 km reader-to-tag eavesdropping range detection ranges (~detect presence of readers/tags)

11 2. Security and privacy problems Authentication problems authenticity of tags? - copy RFID tags (~tag cloning) - RFID simulation devices Signature(tag_data) - prevents forging of data - does not prevent copying of data solutions: cryptographic operations performed by tags application: disabling/replacing tags bags that prevent penetration of radio waves

12 RFID Security and Privacy: A Research Survey 1. Introduction 2. Security and privacy problems 3. Basic RFID tags 4. Symmetric-key RFID tags 5. Conclusion

13 3. Basic RFID tags basic RFID tags = no cryptographic operations (~less expensive) A. Privacy killing/removing tags - dead tags tell no tales - killing command PIN protected (32 bit) - eliminates post-purchase benefits sleeping tags - management problems: PIN vs no PIN PIN

14 3. Basic RFID tags A. Privacy renaming tags minimalist cryptography at tags - encrypting tags not enough (~meta identifiers) - renaming/suppressing tags prevents tracking and tracing - tag keeps a set of pseudonyms - controlled release of pseudonyms relabelling by readers product type identifier 1 tag object identifier 2 tags re-encryption by dedicated readers C = EPK(serial_number) C = EPK(C) SK C = EPK(C )

15 3. Basic RFID tags A. Privacy proxying approach - consumers carry their own privacy-enforcing devices for RFID - device intermediates reader requests PIN RFID Guardian - implements advanced privacy policies - advanced communication protocols distance measurement trusted untrusted learning distances

16 3. Basic RFID tags B. Authentication counterfeiting RFID tags PIN protection EPC EPC, PIN PIN C. Conclusions privacy and authentication features depend on PINS PIN distribution???

17 4. Symmetric key RFID tags symmetric-key RFID tags = cryptographic operations (~more expensive) some cryptographic basics hash function: X= H(M) encryption function: decryption function: C = ek[m] M = dk[c] secure random gen: number = random()

18 4. Symmetric key RFID tags A. Cloning Ti R ki H(ki, R) weak implementations due to resource constraints tag key T1 T2 T3 TN k1 k2 k3 kn

19 4. Symmetric key RFID tags Relay attacks (~man-in-the middle attacks) Ti ki leech ghost Ti R R H(ki, R) H(ki, R) creating appearance of physical proximity

20 4. Symmetric key RFID tags B. Privacy Ti R ki H(ki, R) tag key T1 T2 T3 TN k1 k2 k3 kn privacy? Weis, Sarma, Rivest, Engels ki E H(ki,P) P, E efficiency? complexity of key search: linear to number of registered tags

21 4. Symmetric key RFID tags tree approach (Molnar and Wagner) k2,k5, k12 k1 P,E1,E2,E3 E1 H(k2,P) E2 H(k5,P) E3 H(k12,P) k2 k3 k7 k4 k8 k9 k5 k10 k11 k6 k12 k13 k14 k2,k5,k12 disadvantages: - more complex architecture - compromise of secrets in fraction of tags results in compromise of secrets in other tags depth = d = 3 branching degree = b = number of tags = db = 8 Search complexity = d*b = 6

22 4. Symmetric key RFID tags synchronisation approach (Ohkubo, Suzuki,Henrici) SK=ki P=ci E H(k2,ci) E tag key T1 T2 T3 TN k1 k2 k3 kn H(k1,ci) H(k2,cj) H(k3,ck) H(kn,cx) H(k1,ci+1) H(k2,cj+1) H(k3,ck+1) H(kn,cx+1) number of tags Search complexity disadvantages: - more complex architecture - malicious reader perform denial-of-service attack update ci only after successful mutual authentication use limited number of ci s H(k1,ci+d) H(k2,cj+d) H(k3,ck+d) H(kn,cx+d) = n = log(d*n)

23 4. Symmetric key RFID tags C. Implementing symmetric-key primitives on RFID tags - set of lightweight cryptographic primitives [Vajda & Buttyan] - lightweight hardware implementation of AES (128-bit version) [Feldhofer, Dominikus and Wollkerstorfer] D. Conclusions tag key T1 T2 T3 TN k1 k2 k3 kn

24 5. Conclusions simple device BUT complex privacy and security challenges - Vakgroep IT Security & Mobility Vakgroep Elektronica DramCo PIN code distribution key management leightweight security protocols signal proces sin g cryptography hardware design acy v i pr s supplyt h rig logi chain stic s

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