Overview of the latest RFID Research 21 st March Overview of the latest RFID Research at Auto-ID Lab, ADELAIDE Alfio Grasso Deputy Director, Auto-ID Lab, Adelaide

Overview of the latest RFID Research 21 st March Overview Auto-ID Lab, Adelaide Security Anti-Counterfeiting and Security Authentication Lightweight Cryptography Specialised RFID Tag Antenna Design Conclusions

Overview of the latest RFID Research 21 st March Adelaide, Auto-ID Lab

Overview of the latest RFID Research 21 st March The Auto-ID Laboratories

Overview of the latest RFID Research 21 st March Auto-ID Labs One of 7 Auto-ID Labs around the world MIT, USA Cambridge, UK Adelaide, Australia Keio, Japan Fudan, China St Gallen, Switzerland ICU, Korea

Overview of the latest RFID Research 21 st March Three entities Auto-ID Lab EPCglobal research  via sub-award from MIT RFID Automation Contract Research  Eight Consultancies  One Research Contract  One Research Project Australasian Adoption Research Initiative RFID adoption, Networking, Resources

Overview of the latest RFID Research 21 st March Contract Research Separate from the EPCglobal funded work Commercial Infrastructure Adelaide Research & Innovation Pty Ltd Intellectual Property Protection Pork CRC Research Contract Joint Strike Fighter

Overview of the latest RFID Research 21 st March Auto-ID Lab, Personnel Prof. Peter Cole Mr. Alfio Grasso Dr. Behnam Jamali Mr. Damith Ranasinghe Mr. Kin Seong Leong Ms. Mun Leng Ng Mr. Raja Ghosal Mr. Manfred Jantscher (visiting)

Overview of the latest RFID Research 21 st March Anti-counterfeiting and Security Authentication Lightweight Cryptography

Overview of the latest RFID Research 21 st March Auto-ID Labs In 2006 Global Auto-ID Labs launched the Flagship Project Anti-Counterfeiting and Secure Supply-Chain Focuses on protection against counterfeiting and on product traceability. The main emphasis is on EPC technology without neglecting other methods. In addition to the technology, topics include the impacts on processes within an enterprise, the assessment of customer acceptance and the analysis of business cases in order to examine operational efficiency.

Overview of the latest RFID Research 21 st March RFID Channels Insecure communication channel Authorised Interrogator Powering channel Forward channel (Reader to Tag commands) Backward channel (Tag to Reader responses) Legitimate Tag Physical channel

Overview of the latest RFID Research 21 st March Security and Privacy Concepts Security aims Confidentiality Integrity Authentication Non-reputation Availability Privacy aims Anonymity Unlinkability

Overview of the latest RFID Research 21 st March Security Models Unconditional security Perfect security, assumes unrestricted computational power of an adversary Computational security No known algorithm to break it within polynomial time Practical security No breaking algorithm within N operations, with N chosen to be high. Modern primitives offer practical security. Provable security Possible to show the complexity of breaking a primitive is equivalent to solving a well know supposedly hard mathematical problem

Overview of the latest RFID Research 21 st March Security Services Confidentiality Only authorised parties receive information Authentication The ability of a party to be sure the message is from a claimed source Integrity Assures us a message is not altered on the way Non-reputation Proof of transmission and reception Access Control Restricts and controls access to a system Availability Provides means to assure a system is available when needed

Overview of the latest RFID Research 21 st March Attacks Ciphertext-only attack Known-plaintext attack Chosen-plaintext attack Adaptive chosen-plaintext attack Chosen-ciphertext attack Adaptive chosen-ciphertext attack Known-key attack Man-in-the-middle attack Replay attack Impersonation attack Dictionary attack Incomplete session attack

Overview of the latest RFID Research 21 st March Some Security Issues Eavesdropping Corporate espionage. Victim of theft Cloning and Physical attacks Fraud: counterfeiting RFID-labeled items. Theft: replace merchandise with decoy label. Denial of service. Corrupt data with fake tags. Disrupt RFID-dependent infrastructures. Communication layer weaknesses Insecurities from tag generated random numbers Power analysis of the powering channel

Overview of the latest RFID Research 21 st March Some Privacy Issues Profiling Identify a person’s interest by the RFID items they carry Tracking Any RFID item can potentially identify the person If a payment is made via a credit card, any tags on that person can be used to identify that person, and track them Once the identity is known they can be tracked. RFID enabled currency can be used to determine cash on a target.

Overview of the latest RFID Research 21 st March RFID Security Framework Low cost labels gates available for security (cost limitation). Time available for operations : ms. Label reading speeds: labels/s. Data transmission rates: in the order of 100kbps. Labels reveal their presence through a non-identifying signal. The long term security of label contents can not be guaranteed. Power utilization of security related silicon should not exceed the tag power consumption range of microwatts.

Overview of the latest RFID Research 21 st March Initial Proposals Kill tags at checkout. Customers may want to build applications. Erase unique identifiers at checkout. Still allows tracking by tag “constellations”. Restrict and detect unauthorized reads. Cheap to build, hard to always detect. Some scope is found with security schemes designed with reader distance based trust Use strong cryptography to protect tags. Too expensive for low-cost (5-cent) tags.

Overview of the latest RFID Research 21 st March Cryptography

Overview of the latest RFID Research 21 st March Kerchoff’s principle Do not rely on keeping an algorithm secret. Even if you think no one will think of it, someone almost certainly will. Publish an algorithm but keep the key secret. That key should be chosen from amongst a large number of possible keys, that could be used. Have some mathematical foundation for the belief that it will be hard to extract the key from what can be overheard.

Overview of the latest RFID Research 21 st March Shannon insights Add confusion and diffusion Confusion: encoding the information, e.g.  Swapped (A -> X), shifted (A +3 =D), or A c (mod p), Diffusion: spreading the information, adding redundant information, or noise

Overview of the latest RFID Research 21 st March Public Key Cryptography Public key ciphers Examples RSA Diffie-Hellman ECC Digital signatures These form the second group of keyed cryptographic tools. Based on key pairs instead a single shared key. Only one key need be kept secret. Sometimes called asymmetric key systems. The receiving party issues the public encrypting key and keeps to itself the decrypting key.

Overview of the latest RFID Research 21 st March Public Key Encryption The key pair used in the example is the secret key SBob of Bob and the public key PBob of Bob.

Overview of the latest RFID Research 21 st March Precautions needed In practice P is prime of 300 digits and a and b are at least 100 digits long Is vulnerable to man in the middle attack Cure is to digitally sign what is sent if a public key infrastructure is available, or use a pre-shared password.

Overview of the latest RFID Research 21 st March Elliptic Curve Cryptography Uses the discrete log problem but over a finite abelian group of points x, y on an elliptic curve y 2 = x 3 + a*x + b mod (p) ECC keys can be shorter for the same security when compared with other systems No mathematical proof of the difficulty has been published but the scheme is accepted as a standard by USA National Security Agency. Keys must be large enough. A 109 bit key has been broken (roughly same security to RSA 640) 160 bits ECC - same security as RSA 1024 bits. 224 bits ECC - same security as RSA 2048 bits.

Overview of the latest RFID Research 21 st March One Time Codes

Overview of the latest RFID Research 21 st March Need for something simpler RFID tags cannot support the computing burdens of the usual systems that are supported by significant computing power at both ends of a communication link, nor even of the lightweight protocols listed above. There is a need for something significantly simpler One Time Codes Only proven security method by Shannon Entropy (1949) Provides Perfect Secrecy

Overview of the latest RFID Research 21 st March One time codes: 1 Have available a set of purely random numbers in the tag and matching tag dependent number in a secure data based Some are to authenticate the tag to a reader, some to authenticate a reader to a tag, some might be to permit authenticated change of tag identity to prevent trace of items Use certain of these to XOR with tag identities to disguise them from eavesdroppers.

Overview of the latest RFID Research 21 st March One time codes: 2 Need a large supply to cater for many authentications Options Reserve a pair for final authentication by end user Recharge in a secure environment Assume an eavesdropper cannot be every where and use old codes for identity change for fresh reader or tag authentications Better to use a shrinking function

Overview of the latest RFID Research 21 st March Shrinking Generators

Overview of the latest RFID Research 21 st March The Shrinking Function Two linear shift registers, A (data) and S (sampling), with different seeds, clocked together. Outputs are combined as follows If S is 1, output is A If S is 0, there is no output and another clock is applied This scheme has been resistant to cryptanalysis for 12 years. No known attacks if feedback polynomials are secret and registers are too long for an exhaustive search.

Overview of the latest RFID Research 21 st March Shrinking Generator Minimal hardware complexity Shrink the output from LFSR R1 Produce irregular sequence K Practical alternative to a one time pads Known attacks have exp time complexity  Keep connection polynomials secret  Use maximum length LFSRs LFSR R2 LFSR R1 Output (K) CE CLK D Q Buffer Clock

Overview of the latest RFID Research 21 st March Physically Uncloneable Functions in RFID

Overview of the latest RFID Research 21 st March Simple challenge-response protocol Reader chooses a challenge, x, which is a random number and transmits it to the label. The label computes and transmits the value y to the reader (here e is the encryption rule that is publicly known and K is a secret key known only to the reader and the particular label). The reader then computes. Then the reader verifies that. )(xey K 

Overview of the latest RFID Research 21 st March A lightweight primitive Physically Uncloneable Functions Easy to compute but hard to predict Alternative to storing keys on insecure hardware devices f(c 1,c 2,c 3,…,c m, k) { c 1,c 2,c 3,…,c m } }1,0{),...,,,( 321  n ccccc where {r}{r} }1,0{),...,,,( 321  m rrrrr k ={ gate and wire delay variations due to IC fabrication process variations}

Overview of the latest RFID Research 21 st March Use of PUFs on RFID tags to securely store keys 800 challenge-response pairs to uniquely identify over 10 9 chips PUF structure

Overview of the latest RFID Research 21 st March Tag authentication Use sets of challenges and responses to authenticate tags The response bit string can be compared with that stored in a secure database Similarly to a one time pad, challenges can not be used again

Overview of the latest RFID Research 21 st March Backend support A secure backend database is required to store challenge response pairs A secure method of distributing challenge response pairs are required Labels need to be characterised prior to deployment

Overview of the latest RFID Research 21 st March Lightweight hardware Use XOR operation to allow challenge sets to be reused simple to implement and low computation complexity

Overview of the latest RFID Research 21 st March Mutual authentication Use Reader generated Random numbers Reuse hardware on tag (CRC generator) Achieves mutual authentication and prevents unauthorised users from obtaining tag EPC

Overview of the latest RFID Research 21 st March Specialised RFID tag antenna design Tag Constraints Small UHF Animal Ear Tag (pigs) Small HF Animal Ear Tags (pigs, sheep) Compact Metal Mount Tags (UHF) Dual Frequency Tag Antennas

Overview of the latest RFID Research 21 st March RFID Tag Constraints Consist of Basic requirement: - Compact - Reliable - Inexpensive

Overview of the latest RFID Research 21 st March Small UHF Animal Ear Tags

Overview of the latest RFID Research 21 st March A Simple Loop Antenna Front view Back view

Overview of the latest RFID Research 21 st March UHF ear tag

Overview of the latest RFID Research 21 st March Small HF Animal Ear Tags

Overview of the latest RFID Research 21 st March HF ear tag

Overview of the latest RFID Research 21 st March Compact Metal Mount UHF Tag

Overview of the latest RFID Research 21 st March Metallic Environment Surrounding  Warehouses full of metallic shelves  Industrial area with heavy machinery Object to be identified Canned food Metallic mechanical parts Metallic beer kegs Challenge To get sufficient fields to reach RFID tag antenna near metal.

Overview of the latest RFID Research 21 st March Common Tag for Metallic Objects Conventional planar passive UHF RFID tags not suitable for metallic item identification. Existing RFID tags Normally big in area. To be small, need high dielectric constant substrate which may be expensive.

Overview of the latest RFID Research 21 st March Design Concept Small in size Hrec = 10 mm, Lrec = 25 mm, Wrec = 5 mm Exploits the theory of boundary conditions for better performance

Overview of the latest RFID Research 21 st March Compact UHF Metal Mount Tag The UHF antenna design for tagging metallic objects Small top loaded monopole above a ground with a series inductor to achieve a reasonable match to the RFID chip impedance.

Overview of the latest RFID Research 21 st March Dual Frequency Antenna UHF and HF

Overview of the latest RFID Research 21 st March Dual Frequency Antenna Supply Chain uses UHF Range Some Item Level Tagging application require HF Local Fields (reduced read range) No known impact on materials,  Pharmaceuticals Both UHF and HF Item Level Tagging workgroups defining an air interface protocol that is functionally equivalent Chip designs may soon be released that conform to both EPCglobal’s HF and UHF specifications Need for a two port dual frequency antenna

Overview of the latest RFID Research 21 st March Concept Merge HF loop antenna and UHF dipole antenna, by providing a matching circuit Transforms the UHF short circuit present at the HF antenna terminals to an open circuit at the UHF dipole HF antenna consists of overlapping coils to provide capacitance Gap on UHF antenna prevents short of HF antenna, but strip on underside provides a UHF path.

Overview of the latest RFID Research 21 st March Practical Example

Overview of the latest RFID Research 21 st March Conclusions

Overview of the latest RFID Research 21 st March Conclusions Auto-ID Lab, Adelaide setup to provide assistance to Australasian Industry in adopting EPCglobal technology Current research directed to RFID solutions in security, authentication, and anti-counterfeiting Public Key Cryptography and or Secret Channel, Symmetric Key, (eg: DES, newer AES) are all well established but cannot be applied, directly to RFID tags  Severe cost constraints and other limitations restrains the use of complex security engines Some approaches using one time codes, PUFs and shrinking functions are promising. Vulnerabilities are still being researched. Active research and development in small UHF and HF tag antennas

Overview of the latest RFID Research 21 st March Most papers and presentations on our website

Overview of the latest RFID Research 21 st March Questions

Overview of the latest RFID Research 21 st March Further Information Alfio Grasso Deputy Director Auto-ID Lab, Adelaide University of Adelaide Web: autoidlab.eleceng.adelaide.edu.au/autoidlab.eleceng.adelaide.edu.au/ Ph: Mob: