2. DESIGN OF RADIO FREQUENCY IDENTIFICATION
SYSTEM SECURITY METHOD
Supervisor
Dr. Imran Ali Jokhio
Co-Supervisor
Prof. Dr. B.S.Chowdhry
Presented By
Durr Muhammad
B09MEESE-58
Institute of Information and Communication Technologies
Mehran University of Engineering & Technology
Jamshoro Sindh

3. PRESENTATION OUTLINE
 Introduction
 Background
 RFID System
 Aims and Objectives
 Literature Review
 Methodology
 Cryptographic Approach
 Simple scheme for tag Authentication
 Authentication Protocol Proposal
 Protocol Description
 Conclusion
 References

4. Introduction
 Radio Frequency Identification (RFID) Technology uses radio waves to
automatically identify wirelessly.
 Contact less
 Without visibility
 Privacy and security concerns slow down the fast adaption of RFID technology for
many application. A number of authentication protocols that address these concerns
have been proposed but real-world solutions that are
 secure
 maintain low communication cost
 And can be integrated into EPCglobal C1G2 tag protocol.
 This thesis represents a novel authentication protocol which offers a high level of
security through the combination of random key scheme with a strong cryptography.
This protocol is applicable to,
− Memory Resources
− Power
− Computational constraint platforms such as RFID tags.
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5. Background
 The hindrances of this thesis are,
− Mutual authentication
− Untraceability
− Forward and backward security
− Resistance-to-replay
− Denial-of-service
− Man-in-the-middle
 The proposed protocol is integrated into the EPCglobal C1G2 tag which assures low
implementation cost.
 Keywords :
− cryptographic authentication proposed protocol
− passive computation capable tag
− RFID Systems.
2

6. RFID System
 An RFID system consist of three components:
- Tags
- Reader
- Back-end-server.
 The RFID tags being considered are passive that are powered by the
reader through RF carrier.
 Operating frequency of the reader ranges from 860 to 960 MHz
depending on the local regulations.
 Tags operate with modest amount of energy , however , they can
perform computationally intensive operation such as en/deciphering of
messages.
 Reader is a combination of customary RFID reader and application
software that runs on personal computer.
 Back-end-server is trusted entity that maintains all the crucial tag such
as key tables, timestamps and IDs.
3

7. Continue…
Fig.1. RFID System
4

8. Aims and Objectives
• To investigate security and privacy challenges faced by RFID devices.
• To highlight the privacy and security threats faced due to RFID devices.
• To identify RFID major threats
• To investigate threats impacts with respect to serious consequences
• To investigate measures to overcome Security Issues in RFID devices
• To investigate secure storage and transmission of data
• To design a security method to secure RFID tag.
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9. Literature Review
• Weis, S., Sarma, S., Rivest, R., Engels, D: from Laboratory for
Computer Science and Auto-ID Center introduced Low-Cost RFID
System in which they analyze the security and Privacy Issues (2004).
• Security Issues are:
-- Eavesdropping,
-- Traffic analysis (Location Privacy),
-- Spoofing (aid thieves) or denial of service.
• Privacy concerns are removing and stealing tag.
• They used different schemes
• Hash-Based Access Control (locking or unlocking tag and managing
key in database to ensure forward security)
-- Spoofing is not protected
-- Replay attack occur
6

10. Continue…
• Random Access Control
-- Pseudo-random number generation (past transaction guarantee)
-- Brute-force search (not better for large databases)
-- XORing technique is used (XOR provide no security)
-- Randomized version to disguise the ID so that output is not
fixed overtime but impersonation is the serious security flaw.
-- Not embedded with EPCglobal standard.
• Silent Tree Walking
--Binary tree walking anti-collision algorithm to derive tag contents.
-- This scheme does protect against long-range eavesdropping
of forward channel with little added complexity .
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11. Continue…
• Dimitriou, T.: Athens Information Technology, A light-weight RFID
Protocol to protect Traceability and Cloning Attack (2005). He
presents RFID authentication that enforces user privacy and protect
against tag cloning .
• Common secret and PRNG used to obscure the message contents.
• Simple and enhanced protocol rely on the secret shared key
between reader and tag (back-end database).
• Impersonation, replay or cloning, protection against these attacks
but not all.
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12. Methodology
 Surveying RFID applications.
 Selection of a candidate application. (SCM)
 Analysis of the candidate application to devise security requirements.
 Analysis of attacks on RFID tags.
 To devise an attack taxonomy in the context of candidate application.
 To design a security method for RFID tags in the context of candidate
application.
 Evaluation of the security method with formal methods.
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13. Simple Tag Authentication Scheme
 In this scheme, authentic reader and tag share a common secret K. when
reader challenge a tag with a random number ra , the tag performs the
function C on the challenge ra using the secret K. Then it backscatters the
result m to the reader .
 If C is reversible and the secret K is known, the reader can reveal the
original challenge . As an authentic tag knows the secret K, the reader will
authenticate the tag.
ra
Reader Tag
m performance analysis , m=C(ra, k)
Reader Tag
Authenticate the tag if
ra=C-1(m, k)
Fig.2.Simple Tag Authentication Scheme.
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14. Continue …
 In this scheme followings are the main key features of the protocol,
− Novel authentication protocol that is based on private key Cryptography
− the protocol is applicable to passive RFID tags.
− protocol is embedded with EPCglobal C1G2 standard protocol.
− Employing of Ciphers to hide the message content.
− Use the resources of WISP tag platform to implement Ciphers.
 Tag-to-reader is the main bottleneck of an RFID system because passive tag can
harvest power from a reader which is the main trade-off between security and
computation/ communication cost.
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15. Cryptographic Approach
I am Asad
 Identification.
- Claim to be have a
certain identity
(e.g. username)
 Authentication.
- Proof of identity
- Showing knowledge,
- possession, inherent
feature
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16. Continue….
INTERROGATATOR TRANSPONDER
Query [2] Evaluate slot counter.
[1] Reader issues a query
command. a) If the slot counter is zero then the
tag responds with RN16.
RN16 b) If slot counter is not zero then
Identification
decrement slot counter.
[3] Reader Acknowledges tag by ACK(RN16) [4] Evaluate RN16.
issuing ACK with same RN16. a) If RN16 is valid then respond with
EPC .
b) If RN16 is invalid then do nothing.
[5] Reader issues Req_RN [6] Evaluate RN16:
containing same RN16. If RN16 is valid then respond with
handle .
Command (handle XOR PW-low) b) If RN16 is invalid then do nothing.
[7] Reader issues access [8] Decrypt PW_low by XORing
command using handle to Req_RN (handle) handle.
Authentication
cover code the password [10] Evaluate RN16
(PW_low). handle (handle) a) if RN16 is
valid then respond with
[9] Reader issues Req_RN
EPC.
containing handle.
b) If RN16 is invalid
Command (handle XOR PW_high) then do nothing.
[11] Reader issues Access [12] Decrypt PW_high by
command using handle to cover XORing handle .if PW_low
code the password (PW_low). and PW_high are correct
then authenticate reader and
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allow further operation.

17. Protocol Authentication Proposal
 This proposed cryptographic authentication protocol that is same computational
and communication abilities like YA-TRAP because YA-TRAP also places low
computational burden on the tag. The main design goal is to
− Retain high level of security
− Low implementation costs.
 Improving the weaknesses of YA-TRAP which is susceptible to
− DOS attack because the reader can transfer the data (in particular the timestamp Tr)
without fully authenticating itself to the tag.
− Ciphers in place of one-way-hash function to keep the message content secret.
− Security relies on key tables (A and B) that are stored at the tag level.
 Key tables are generated during the manufacturing process and along with a
primary timestamp Tt and the tag’s ID (EPC) they are written on the tag.
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18. Continue…
 The main idea of the proposed protocol is that a tag can authenticate the
reader/server as only an authentic entity can know the unique key pairs.
Key table A Key Table B
Index Key
Index Key
keyA[i] 0x03… Key Pair
KeyB[i] 0x03…
keyA[i+1] 0x01…
keyB[i+1] 0x01…
Key Pair
keyB[i+2] 0xAF…
….
….
keyA[n] 0xAF…… Key Pair
….
….
Fig.3 KEY TABLES
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19. Continue…
Tag ID Tag Table Index Key
Timestamp
1 0 A i 0x03…
1 0 A i+1 0x01…
….
….
….
….
….
1 0 A n 0xAF…
….
….
….
….
….
1 0 B I 0x03…
1 0 B i+1 0x01…
….
….
….
….
….
1 0 B n 0xAF
….
….
….
….
….
Fig.4.Server Data Base. 16

20. Protocol Description
READER/SERVER TAG
m1 =Rr Generate Rt
Generate and transfer Rr
Look up keyA[Rt] and KeyB[Rt+1]
Encrypt Tt and Rr with keyA[Rt]
Fetch subset KA of all keys with number Rt and
h1 = h(Tt||Rr,KeyA[Rt]
associated tag timestamps Tt(i). m2 =Rt||h1 Reply h1 and Rt
WHILE(key found=false)&& (i<#of keys)
Decrypt h1:[Tt,Rrt]=h(inv)(h1,key)
IF (Rr=Rri): key found=true End IF End WHILE
IF (key found=true): delete all keys KA except the
Decrypt h2 with keyB[Rt+1]
one found . Check if one of the associated tag
[Tr,Rt]=hinv(h2,keyB[Rt+1])
timestamps
IF Tr>Tt:
Tti matches Tt. IF this is not the case, generate a
Update timestamp Tt=Tr
warning. Store assumption about m4.
Set key key=keyB[Rt+1]
Fetch th related key keyB[Rt+1] and encrypt the
ELSE:
reader
Set key key = keyA[Rt]
Timestamp and Rt: m3=h2=h(Tr||Rt,KeyB[Rt+1])
END IF
ELSE:
m3 =h2 Encrypt ID and timestamp with key
Generate random number: m3=Rr2
m4 =h3=h(IDXORTt,key)
END IF
ELSE:
Reply m3
Generate and reply random
Number Rt2
Decrypt h3 with the key keyA[Rt] or keyB[Rt+1]
m4 =Rt2
based
END IF
On assumption about m4.
Reveal tag ID based on assumption about m4 by an
m4 =h3 Reply m4
exclusive OR operation with Tr or Tt
Authenticate the tag if it is one of the possible tags.
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21. Continue …
 The authentication process can have three possible scenarios:
[1] Reader is not authentic: Reply random number Rt2.
[2] Reader is authentic but timestamp is wrong: Use keyA[ Rt ] to encrypt h3 and do
not update the timestamp.
[3] Reader is authentic and timestamp is right : Update timestamp and use keyB[ Rt+1]
to encrypt h3.
 The reader can authenticate the tag based on the assumption made after the first
round.
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22. Conclusion
 The security features of different protocols are to be analyzed to design the
secured RFID system.
 Security and privacy threats are described and used encryption method that
gives better way to secure communication. Encryption may either symmetric or
A-symmetric because both have their own issues.
 This proposed protocol provides:
− Mutual authentication
− Untraceability
− Forward and backward security
− Resistance-to-replay
− Denial-of-service
− Man-in-the-middle
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23. References
[1]. S. Liu, O.V. Gavrylyako, P.G. Bradford, Implementing the TEA algorithm on sensors: Department of
Computer Science , The University of Alabama, 2004.
[2]. Asif Z., Munir M, Integrating the Supply Chain with RFID, In: Fox School of Business and
Management Temple University (Volume 15, Article 24, March 2005)
[3]. G. Tsudik, YA TRAP: Yet Another Trivial RFID Authentication Protocol: CS Department , University
of California, Irvine, 2006.
[4]. Thorsten B., George Q., RFID in Operations and Supply Chain Management (2007)
[5]. H. Chae. D.J. Yaeger, J.R. Smith, K. Fu, Maximalist cryptography and computation on the WISP UHF
RFID Tag, in: proceedings of the International Conference on RFID security, 2007.
[6]. G. Tsudik, A family of dances: Trivial RFID identification and Authentication Protocols, in:
Computer Science Department, University of California, Irvine, 2007.
[7]. Omer k., Beygo., C., Eraslan, Enhancing Security and Usability Features of NFC, In: School of
Computing Blekieng Institute of Technology Sweden (Thesis no: MCS 2009-30, September 2009).
[8]. Dr.V., Coskun, Kerem Ok, Current Issues in Near Field Communication Technology, In: ISIKI
University, Istanbul, Department of Information Technology (University of Thessaly September 23rd,
2010)
[9]. Kapil N., Vhatkar, G., P., Bhole, Internal Location Based System for Mobile Devices Using Passive
RFID and Wireless Technology (2010).
[10]. Gul N. Khan, X. Yu, F.Yuan, A novel based authentication Protocol for RFID Systems, Department of
Electrical and Computer Engineering, Reyrson University, Toronto, canada, 2011.
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