RFID: Importance, Privacy / Security Issues and Implementation

Rashid Aziz Faruqui and Ejaz Tayab Department of Computer Science and Engineering

Bahria University, Karachi Pakistan Email: rashid@bimcs.edu.pk

Abstract — RFID technology can be truly called old wine in new bottle as it is around the globe since 1940 but mainly in military domain. Lately high expectancy of users in automatic identification data collection, enormous gain and avenues offered by RFID attracted scientists, researcher and vendors to revamp this technology. Out of myriad of technologies emerging, RFID has attracted people from all walks of life. The objective of this research study is two fold; first and the foremost is to analyze this technology in depth and secondly propose its implementation in Pakistan’s environment through the phase deployment of RFID systems. Cost of the equipment has not been worked out.

I. INTRODUCTION Numerous technologies emerge and die down if they do not satisfy user requirements. On the contrary those which can benefit the users grow enormously to the extent of bringing revolution around the globe. One such technology is Radio Frequency Identification commonly referred as RFID. RFID (Radio frequency identifications) as the name implies uses radio frequency to exchange data between two entities for identification purpose. It is a wireless technology to collect information with out any human interventions [1]. The need of this technology was felt when AIDC (Automatic Identifications Data Collection) came into lime light and product identification become a necessity. Simple labeling systems allowed traders to identify packages without having to individually inspect each package [2]. RFID because of its flexibility and easy to use characteristics has taken the world by storm. It is one of the most rapidly growing technologies. It combines advantages not available with other identifications technologies [3]. Conceptually it works in similar manner as that of bar coding but with added advantages.

II. COMPONENTS OF RFID SYSTEM In its simplest form a RFID system consists of an RFID device also called transponder or tag that contains information about the concerned device on which it is placed and a reader used to read or write information on a tag and passing that information to a system for storage and processing.

Computer/Processor

Figure 1: Various Components of RFID Systems [26]

A. RFID Tags A RFID tag has an imbedded microchip and a coiled antenna to receive and transmit electromagnetic energy to and from a reader. The IC chip has a memory that may be volatile or nonvolatile. Tags are classified according to its source of power that determines both its range and cost [4]. Tags can be divided into three categories:

1) Active Tags These are normally more expensive, larger size compared to passive tags. Active tags actively transmit data to a reader. They use batteries to power its transmitter and receiver and its life depends upon the battery life [3]. These have longer ranges compared to passive tags and up to 300 feet range tag is commercially available.

2) Semi Passive Tags These tags contain batteries as such do not require energy to power the onboard chip. These can operate with [16] lower power levels thus achieve longer distances up to 100 meters. It is worth mentioning here that the distance limitation imposed on these types of tags is mainly on account of absence of integrated transmitter. These use battery but only to retain memory in the tag and not to supply power to electronics enabling tag to modulate the reflector signal [3].

3) Passive Tags These draw power from the magnetic field generated between itself and a reader to power its microchips circuits. These reflect the RF signal [3] transmitted from a reader and add information by modulating the reflective signal. RIFD tags are also distinguished by their memory type such as Read/write and read only.

RIFD tags are also distinguished by their memory type such as Read/write and read only.

1-4244-2427-6/08/$20.00 ©2008 IEEE

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Figure 2 Various types of Tags [29] Read/write: These are dynamic in nature and can be read and also written i.e. its data can be altered. Read only: Data can not be altered and are generally factory programmed. These are less expensive compared to other types which is one of the major issues in RFIDs further growth. Read/write Active Tags: can also be used for peer-to-peer communication, i.e. without readers and can also accommodate sensors.

B. Readers These are used to interrogate tags to acquire data stored in them through the air interface. Readers are of different types depending upon the applications these are used in terms of [2] internal storage and the processing power. The channel from reader to tag is called “forward channel” and vice versa “backward channel”. The readers consist of radio frequency module [28], a control unit and a coupling element to interrogate the tags via RF. Readers also have an interface with some backend database containing detailed information about the tags. The distance at which a reader can read a tag depends upon the frequency spectrum, the placement of the reader and types of tags being interrogated.

C. Data Base Generally all systems consist of a data base running at back end to look up detailed contents acquired from the tags. The [2] connectivity between reader and database may be secure and depends upon the organization where it is being used.

D. Operations In its simplest form a reader transmits electromagnetic waves towards tag. The tag device responds to the transmission. The data received at the reader may be sent to a host computer or retained in the reader for later retrievals at an appropriate time and place. The automatic reading and direct use of the ‘Tag’ data is often called automatic data capture [4]. In case of passive tags reader transmits frequency normally in the range of low frequency through antenna for duration of 50 m sec. This generates a magnetic field and is received by antenna of the tag. The tag knows the transmitted frequency and is tuned accordingly. The magnetic field so generated is stored in a capacitor attached to the transponder. After the above said transmissions have been received, tag transmits its data using the energy stored in the capacitor as source of power. Generally 128 bits of data is transmitted over a period of 20 m sec [4]. Reader may store the received data in its buffer temporarily or transfer it to another system attached to it for further analysis.

III. TRANSMISSION TECHNIQUES The transmission technique used mostly at air interface between reader and the tag is ASK (Amplitude Shift Keying) [28] on account of its flexibility, easy to use resistance to noise and cost effectiveness to commercialize.

A. Air interface The area between a reader and a tag is called communication channel. There are two types of physical phenomena for interaction between the tag and the reader depending upon the range and frequency spectrum. These are [5]: Inductive coupling Propagation coupling

1) Inductive coupling This type of communications also called near field system is based on close ranges between the tag and the reader. The tags using this principle are generally passive and operate at ranges less than 3m in frequency bands of LF and HF.

Figure 2 Inductive coupling [26]

2) Propagation coupling

This principle called far field system is generally used by active tag operating at ranges between the 1 to 300m in UHF and microwave RFID system [6].

Figure 3 Propagation Coupling [4]

B. Channel Encoding The transfer of data without errors through the media is called channel encoding. This is mainly dependent on bandwidth and power consumption. The codes used in RIFD systems are: Level codes – Uses specific voltage values. Transition codes – Uses transition between voltages.

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Figure 5 Encoding Schemes [2] Use of PPM on forward and Manchester on reverse channel. [2] is recommended.

C. Modulation Superimposing of data on carrier wave to carry it to different ranges is called modulations. ASK, FSK and PSK are the three well known mechanisms. The difference of power between tags and readers cause hindrance as signal from tag to reader may be interfered by the signal from reader to tag. Solution proposed to prevent is [2] that the return signal from Tag to the Reader is modulated on to a different frequency from tag to the reader.

D. Anti Collision When a reader reads a single tag, multiple tags in the vicinity may respond which may ultimately lead to interference thus collision. The solution is to deploy anti-collision algorithms. The algorithms defined are Binary Tree, Aloha and Slotted Aloha. All such algorithms fall under the two broad categories; “Probabilistic” and “Deterministic” in the similar manner as used in fixed types of Network – Multi user environment. The higher number of tags in the vicinity of Reader would have higher collision rate which leads to degraded performance. Generally the values for reads are 200 tags/sec for UHF and 50 tags/sec for HF [2].

1) Probabilistic Algorithms Aloha and Slotted aloha are the most common algorithms used in LAN environment. In case of RFID systems, tags delay their responses to avoid collision. Generally slotted aloha algorithm is supported by ISO by virtue of being more efficient [2].

2) Deterministic Algorithms Binary tree is one of the examples of such algorithms. In this mechanism a reader access the branches of binary tree isolating a single tag by a process called “Singulation”. Uniqueness of tag ensures successful operation of such mechanisms. The selection of mechanism is dependent upon various factors such as range, bandwidth requirement, performance etc [2]. It has been analyzed and proved that probabilistic algorithms consume less bandwidth while deterministic algorithms are more efficient. Tags operating in high frequency such as 13.56 MHZ use probabilistic algorithms while those in 915 MHZ band the deterministic algorithms.

E. Media Access Protocols There are four fundamental characteristics which make RIFD networks distinct from other wireless systems; large scale, remarkably low cost, very small size and traffic comprising of short and simple messages.[18] Two most widely used protocols for RFID technology are variants of TDMA (Time division multiple access) and CDMA (code division multiple access) namely slotted Aloha/TDMA and DS (Direct sequence)/CDMA.

1) Slotted Aloha/TDMA The operation comprises 3 phases namely message control phase, data transfer phase and selection phase. In the selections phase [19]tag – IDs successfully received are allotted slots in the next message control phase. When tag finds its ID in frame control message, it transmits data to the interrogator in data transfer phase.

2) DS/CDMA Each tag is assigned separate code (4.4 trillion possible codes are available) which are independent of transmitting data message. Data signal originated from tag is modulated by a pseudo random noise code which spreads the spectrum of signal. Interrogator de-spread and demodulates the received signal to recover the original message. The performance of the above 2 techniques was compared with the help of direct event simulations [19]. It was proved that DS/CDMA out performed slotted Aloha/TDMA both in terms of faster message and different traffic loads [19]. RFID technology on account of being small and highly inexpensive puts extra constraints on the access protocols under use. The protocols must be highly energy conserving as well as have minimum delay factor. The present implemented protocols which fall under the category of Random Access Protocols are not energy conserving at all and those under the domain of Deterministic protocols cause unacceptable delays. Three classes of protocols proposed were [18] grouped– Tag TDMA protocols, Directory protocols and Pseudo Random protocols.

IV. FREQUENCY SPECTRUM Various frequency spectrums behave differently in different environments. All the frequency spectrums can not be used on account of the regulations imposed in different countries. Also the size and price of tags are to be kept in mind while selecting the frequency to be used. The above constraints reduce the use of frequencies to few selected spectrum only and referred as RFID technology [15]. The frequencies used are 2.45 / 5.8 GHZ in microwave band, 433/869/915 MHZ in UHF band, 13.56 MHZ in HF band and 125/134 KHZ in LF band.

A. LF & HF Tags These communicate with reader using amplitude modulation employing inductive coupling.

B. UHF Tags These types of tags use the technique called back scatter to communicate with the reader using amplitude modulations.

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“Sky is the limit” was perhaps said for the myriad of applications, which may benefit from this emerging technology. The organizations belonging to various walks of life, which have and are using this technology have seen enormous benefits which can accrue from it. Those who have not done it and have just heard about the benefits are vying to incorporate it at the earliest. Although this technology is in nascent stage but seeing its bright future Wal-Mart (USA) and DOD (Department of Defense) are sponsoring to implement it. Wal-Mart has asked its entire product suppliers to make their products RFID compliant by the year 2005. The benefits include cost savings, efficient goods handling, reduced losses thus optimizing efficiency and performance. There are numerous applications [16] spread from small manufacturers to large industries which can benefit from this technology. The important ones are Supply Chain, Identification in Large ware houses, Health and Pharmacy, Recreational Facilities, Books Management in Libraries, Cashless payment, Security and Toll Payment. RFID has made strides in almost all the areas and its implementation in getting momentum with every day passing. There are number of other applications such as air baggage tracking, live stock tracking, parcel shipping system, hotel room access, prudent tracking system, valuable asset tracking etc [11] where RFID system have penetrated and their performance is up to the entire satisfaction of the customers.

Figure 6 Two Different Ways of Energy Transfer [16]

V. PERFORMANCE The performance of an RFID system can be measured according to metrics and its usage, applications and the environment it is being deployed. However generally speaking following may be some of the metrics [15]:

Distance or range of communication Data rate to exchange information Size of the tag and the information Capability to communicate with multiple tags Strength to overcome interference due various

materials between the tag and the reader The aforesaid metrics are dependent mainly on frequency spectrum being used and the type of tags deployed.

VI. STANDARDS RFID systems are expected to be deployed round the globe, standardizations would ensure its successful deployment. Regulations with respect to RFID systems involve number of parameters. Most important are:

Power emissions of the readers. Allocations of frequency bands.

The air interface may include modulations type, data rates, communication protocols and Anti-collision algorithms. ISO standards defined for RFID are referred as 180000 series and mainly target air interface only and are different for different frequency spectrum.

A. Classes Five classes [14, 16] from 0 to V that mainly refers to capabilities of tags have been defined.

B. Radiated Power Two standards are currently being used:

EIRP (Equivalent Isotropic Radiated Power) – Used in US.

ERP (Effective Radiated Power) – Used in Europe Relationship is defined as EIRP = ERP * 1.64

C. Frequency Spectrum & Regulations ITU divided the whole world into 3 broad regions which are:

Region 1 – Europe, Middle East, Africa & former USSR.

Region 2 – North & South America and Pacific East.

Region 3 – Asia, Australia and Pacific Rim West. Presently 13.56 MHZ has been internationally recognized [16].

VII. APPLICATIONS

VIII. TYPES OF RFID SYSTEMS There are numerous RFID applications which are being run successfully all around the world. These applications can be further subdivided into four categories which are [7]:

A. Portable Data Capture Systems These consist of portable data terminals with integral readers. These systems are normally deployed at close ranges.

B. Networked Systems These consist of fixed readers normally connected to data terminals to track moving objects or items.

C. Control Systems These systems use tags to initiate the control functions such as access to certain areas and other security features.

D. Positioning Systems These normally comprises of active tags to provide locations and navigational support. Signals from active tags are picked up by positioning antennas and transferred to data terminals for identification and locations.

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IX. COMPARISON WITH BAR CODES There is no comparison what so ever between the two technologies with respect to any metrics except that bar codes are relatively cheap and RF performance gets degraded if immersed in liquid or wrapped in a foil or mesh. The advantages [10] of RFID may be summarized as under:

RFID does not require line of sight communications RFID uniquely identifies an object and this

identification can be done many times RFID reading distance ranges from 3m to 100m. Data may be written a number of times RFID can face harsh treatment and environment. It is free from human interventions It can sense its environment like temperature etc Numerous RFID tags may be read in a short time

X. ELECTRONIC PRODUCT CODE (EPC) Any talk or write up on RFID systems would not be complete with out EPC. EPC is a standard for uniquely identifying items. Every item in the world would be referred through a unique number. It is an emerging RFID standard which is expected to provide enormous help in specific product identifications [10]. EPC would provide enormous benefits in supply chain efficiency and its optimization. It is analyzed that RFID systems without EPC would still be there where it was 5 years ago [16]. EPC works with PML (Product Marks up Language) and ONS (Object Naming Service). ONS: Each RFID tag stores the EPC code. ONS matches the EPC code through a querying mechanism to get the information about that product. ONS server indicates the locations i.e. IP address where information is stored. PML: PML basically describes the physical objects [9]. Savant: It operates in between RFID readers and the servers storing product information. It would [16] provide product information while accessing it through servers. In additions, it would manage RFID reader for false or duplicate reads.

XI. PRIVACY AND SECURITY Any emerging technology is bound to succeed if it meets the privacy and security concerns of the masses.

A. Privacy In RFID system privacy falls under the realm of two domains; personal or individual’s privacy and the manufacturer’s privacy. Privacy could be compromised if personal information such as sizes of clothes worn by a woman, or RFID compliant items are known through readers deployed at various places. Also individuals could be tracked through their personal belongings and revealing of information such as credit card number or of the movie watched through the theatre ticket in the individual pocket do have some strength but not strong enough to curtail the growth of technology which can accrue enormous benefits. A study conducted by university of Florida in 2001 found that $ 5.8 billion (US) worth of inventory was lost due to administrations errors. The use of RFID for tracking the movements of inventory can save hundreds of million or even billions of dollars [10].

Manufacturers have shown concern on spying by their counter parts to know the number of items they have marketed or sold in a store. Surely enough, the concerns are genuine. Privacy groups have made and are making inroads to overcome the said issues. Some suggested approaches [20] to over come aforesaid issues are The “Kill Tag” Approach, The Faraday cage approach, The Active Jamming approach, The Smart RFID Tag approach, The Re-encryptions approach, Silent Tree – Walking, Regulations Approach and The Blocker Tags.

B. Security RFID has its peculiarities on account of its small size therefore all encryptions rules cannot be applied on it as done in other technologies. RFID tags have very rudimentary computational abilities as these are just small un- powered microchips. Relatively costly tags around 50 cents per tag are capable of some limited symmetric – key cryptography [24]. There are various forms of threats which could endanger the RFID system deployed in various applications. Some of those are:

1) Corporate Espionage Inventory system could be monitored and tracked by competitors [16,22].Sales data could be gathered at various times by co relating the changes [23]. The same may be accomplished through eavesdropping and traffic analysis. Spoofing – Valid tags can be replaced by cloned tags to fool the staff that valid items are still in the stock [22]. Another form could be re-writing or replacing tags on expensive tags with spoofed data from cheaper item. Further more, large batch of tags can be disabled or corrupted [23]. This is a form of denial of service attack.

2) Anti – Counterfeiting After the data has been spoofed; similar tags can be purchased and updated with authentic data and put on degraded [16] or in our words number 2 items for sell. Physical attacks can also be carried out in unsecured environment.

3) Security proposals There are number of security protocols [22, 23] which are very much in the offing. The main effort and designing goals of all such protocols is to make them lightweight to keep the cost of the tags within limits. RFID technology offers lot of new avenues to the researchers. A new school of thought is emphasizing the development of efficient hardware to cater the need of the cryptographic systems mainly to curtail the cost of the RFID tags.

XII. DEPLOYMENT OF RFID SYSTEM – IMPROVE LAW AND ORDER SITUATION AT KARACHI WITH RESPECT TO CAR THEFT

Having carried out the technology survey from scratch, it is time for its deployment in our environment. And can there be anything better than to improve law and order situations at Karachi? It is a well-known fact that all the terrorist attacks are carried out mostly through snatched cars. Car snatching/theft, motorcycle theft and smuggling of vehicles have reached alarming proportions and are a source of great concern and

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anxiety [Table 1]. It is not only the loss of vehicle but each

Table 1 Month Wise Figure - 4 Wheelers / Theft & Recovered [26]

vehicle is used for the commission of some form of crimes or acts of terrorism. The state of loss in revenue collection is equally alarming. Estimated loss to national economy due to vehicle theft is approx. Rs. 0.97 billion per year in Karachi only [27].

A. Routes The stolen vehicles are generally removed from Karachi to various parts of other provinces. The routes taken are:

Karachi – Hub Karachi – Jamshoro Karachi – Thatta

Police checkpoints at Karachi include check posts at: Hub river road Manghopir road Superhighway National highway However on account of lack of resources, these are

unable to detect stolen vehicles.

B. Modus operandi The modus operandi is to implement RFID system; RFID tags on all vehicles, reader and interrogator at the various locations through out the city in general and the exit points discussed above in particular. The benefits which would accrue include:

Improve security Reduced revenue loss

It is pertinent to mention here that RFID implementation at Karachi is fairly straight forward and easy process as vehicle registration and related records are already computerized.

C. Proposed Deployment Phases The RFID system would be installed in phases which would consist of installation of tags on all the vehicles and installation of readers at various locations

1) RFID tags installation Phases

To install tags on all newly registered vehicles. Installation of tags on all vehicles registered during

last five years (2000-2004) Installations of tags on all vehicles registered during

1995-1999 and so on (Last 5 years each).

Information stored on tags In addition to the information already held against a vehicle and its owner, the additional information would include:

Vehicle tag number Vehicle status in terms of:

Stolen previously Involvement in crime Involvement in road accidents Under surveillance by law

enforcement agencies

D. RFID Reader Installations Karachi city comprises of various localities spread from east to west and north to south. The areas could be divided from highly volatile to low as per CPLC crime analysis. It is proposed to deploy one fixed reader in 14 areas as shown and 8 on exit points (Figure 7) stated earlier. It is also proposed to

Figure 7 Spatial Crime Analysis System [26]

provide mobile readers to mobile police vans (initially one in each locality, later it could be increased) deployed for surveillance to control law and order situations. All these readers would have databases server at their back ends. Some of the servers are already connected.

E. Apprehension operation Apprehension operation is simple and fairly easy to implement with the help of the above mentioned deployment. When a report is registered for a stolen car normally done within half an hour, the particulars of that car including tag number would be broadcast to all the readers installed at various places including mobile vans operated by police and rangers. When the stolen car moves within the covering area of the reader, indication would be given in the form of alarm, beep or even an e-mail to concerned authorities. If the stolen car remains within Karachi area, its movement can be tracked through the readers deployed at various locations. And if it leaves through some exit points, again it could be located. The vehicles are stolen and kept in underground parking of flats for an unspecified amount of time before being brought back on the roads and driven away from Karachi through exit points. In our case the tag of the stolen car (red entry in the database) would remain under surveillance and scrutiny till vehicle apprehended or red entry removed from the database.

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Therefore apprehension at a later date is even not out of question. This point is highlighted because rate of car theft is so high in Karachi that the vehicle stolen previous day / week are forgotten and those stolen today get all the efforts and priorities diverted towards them. As per CPLC officials this is good business of mostly white collar job people to provide shelter to stolen vehicles mainly in the areas of Gulistan-e-Juhar in underground parking of flats for an amount of Rs.5000 per day.

F. Financial Effects Finances involved are meager and may be peanuts if compared with other projects of the government. It is pertinent to mention here billions of rupees have been allocated to improve law and order situations at Karachi. However financial effects may be worked out if desired. But the same is beyond the scope of the Independent Study but this report can be used for future references. The equipment required includes 14 in number Fixed and Mobile readers each and installation of tags on all the vehicles. The government would only pay for the cost of Readers where as the owner of the vehicles would pay cost of the tags.

G. Infrastructure Requirements Presently there is no extra infra structure required. CPLC runs its operation room and is connected to its zonal offices situated in five zones of Karachi respectively namely central, Malir, East, West and South. All of them are equipped with necessary setup to support RFID phase deployment. These offices are connected through dial ups. In addition to said offices, various law enforcement and defense related agencies can get benefits from the huge and extremely useful database being maintained by CPLC. It is worth mentioning here that long term objectives for any patriotic government would be the computerization of vehicles registration all over Pakistan as soon as possible to curb so many evils emerging from car theft, the discussion of which are beyond the scope of this paper. Being a defense strategist with more than 25 years of clandestine and covert operation experience, it is envisaged that implementation of RFID system is bound to improve the law and order situation in Karachi with wired speed with minimum possible investment. It is believed that the government of Punjab is also in the process of getting RFID system implemented. It is envisaged that RFID technology if implemented in latter and sprit with out any vested interests then it would definitely provide a lead to other provinces- a good omen for Pakistan.

XIII. CONCLUSIONS RFID technology would benefit not only people from all walks of life but all types and sizes of industry and both for commercial and military. RFID technology with respect to tags is highly resource constraint by virtue of its small size, production in large number and extremely low price especially in a race to outclass and outperform barcodes. It is anticipated that a hardware based technology may lead towards a better solution. It goes without saying that RFID technology is not

fool proof; it does have its pros and cons mainly in terms of security and privacy issues. Its implementation with respect to Pakistan’s environment in general and Karachi in particular against vehicle theft and subsequent criminal activity would definitely bring results which are beyond one’s imaginations. The financial effects are meager and benefits are enormous. Need of the hour is to implement it in phases, analyze the result and spread it all over Pakistan.

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