What Explains Current Interest In Rfid Technology

Published Date: 02 Nov 2017

A sensor network is an infrastructure comprised of sensing (measuring), computing, and communication elements that gives an administrator the ability to instrument, observe, and react to events and phenomena in a specified environment. The environment can be the physical world, a biological system, or an information technology (IT) framework. Network(ed) sensor systems are seen by observers as an important technology that will experience major deployment in the next few years for a plethora of applications. Typical applications include, but are not limited to, data collection, monitoring, surveillance, and medical telemetry. In addition to sensing, one is often also interested in control and activation. There are four basic components in a sensor network: (1) an assembly of distributed or localized sensors; (2) an interconnecting network (usually, but not always, wireless-based); (3) a central point of information clustering; and (4) a set of computing resources at the central point (or beyond) to handle data correlation, event trending, status querying, and data mining. In this context, the sensing and computation nodes are considered part of the sensor network.

The technology for sensing and control includes electric and magnetic field sensors; radio-wave frequency sensors; optical-, electro optic-, and infrared sensors; radars; lasers; location/navigation sensors; seismic and pressure-wave sensors; environmental parameter sensors (e.g., wind, humidity, heat); and biochemical national security–oriented sensors. Today’s sensors can be described as ‘‘smart’’ inexpensive devices equipped with multiple onboard sensing elements; they are low-cost low-power untethered multifunctional nodes that are logically homed to a central sink node. Traditionally, sensor networks have been used in the context of high-end applications such as radiation and nuclear-threat detection systems, ‘‘over-the-horizon’’ weapon sensors for ships, biomedical applications, habitat sensing, and seismic monitoring. More recently, interest has focusing on networked biological and chemical sensors for national security applications; furthermore, evolving interest extends to direct consumer applications. Existing and potential applications of sensor networks include, among others, military sensing, physical security, air traffic control, traffic surveillance, video surveillance, industrial and manufacturing automation, process control, inventory management, distributed robotics, weather sensing, environment monitoring, national border monitoring, and building and structures monitoring.

1.2 SENSOR NODE TECHNOLOGY

A WSN consists of a group of dispersed sensors (motes) that have the responsibility of covering a geographic area (the sensor field) in terms of some measured parameter (also known as the measurand); alternatively, a sensor supports a point-to-point link in which the ‘‘reader’’ end is attached to a wire line network (e.g., a stationary tag reader sensing a mobile tag). Sensor nodes have wireless communication capabilities and some logic for signal processing, topology management (if and where applicable), and transmission handling (including digital encoding and possibly encryption and/or forward error correction). Successful development of low-cost robust miniaturized sensors and detection equipment (such as mass spectrometers and chromatographs) will be of benefit; The basic functionality of a WN generally depends on the application, but the following requirements are typical:

1. Determine the value of a parameter at a given location.

2. Detect the occurrence of events of interest and estimate the parameters of the events.

3. Classify an object that has been detected.

4. Track an object.

Sensors are either passive or active devices. Passive sensors in single-element form include, among others, seismic-, acoustic-, strain-, humidity-, and temperature-measuring devices. Passive sensors in array form include optical- (visible, infrared 1 mm, infrared 10 mm) and biochemical-measuring devices. Arrays are geometrically regular clusters of WNs (e.g., following some topographical grid arrangement). Passive sensors tend to be low-energy devices. Active sensors include radar and sonar; these tend to be high-energy systems. Small, low-cost, robust, reliable, and sensitive sensors are needed to enable the realization of practical and economical sensor networks.

1.3 Resource Constraints

Networking implies a need to support physical and logical connectivity. In WSNs, physical connectivity is supported over a wireless radio link of one or more hops, at a distance of tens, hundreds, or thousand of meters. Logical connectivity has the goal of supporting topology maintenance and multi hop routing (when present).

Sensor nodes have to deal with the following resource constraints.,

Power consumption : Almost invariably, WNs have a limited supply of operating energy; it follows that energy conservation is a key system design consideration.

Communication : The wireless network usually has limited bandwidth; the networks may be forced to utilize a noisy channel; and the communication channel may be relegated to an unprotected frequency band.

Computation : WNs typically have limited computing power and memory resources. The implications are restrictions on the types of data-processing algorithms that can run on a sensor node. This also limits the scope and volume of intermediate results that can be stored in the WNs.

Uncertainty in measured parameters : Signals that have been often have various detected or collected degrees of intrinsic uncertainty. Desired data may be commingled with noise and/or interference from the environment. Node malfunction could collect and/or forward inaccurate data.

1.4 RADIO FREQUENCY IDENTIFICATION

The wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purposes of automatically identifying and tracking tags attached to objects. RFID was first used during the World War II in " Identification Friend or Foe " systems onboard military aircraft by British Royal Air Force. Soon after that, Harry Stockman demonstrated a system energized completely by reflected power. The concept of automatic identification using a radio transponder originated in World War II as a way to distinguish friendly aircraft from the enemy. The "friendly" planes responded with the correct identification, while those that did not respond were considered "foes". A coded interrogation signal is sent out on a particular RF, which the transponder receives and decodes. The transponder then replies with encrypted identification information. Each transponder has a unique identifier.

Fig 1.1 EPC-RFID-TAG

1.4.1 what explains current interest in rfid technology

The mandates are seen to have the following effects:

To organize the RFID industry under a common technology standard, the lack of which has been a serious barrier to the industry’s growth

To establish a hard schedule for the rollout of RFID technology’s largest application to date

To create an economy of scale for RFID tags, the high price of which has been another serious barrier to the industry’s growth.

1.4.2 Reinventing the Bar Code

Universal Product Code (UPC) bar code, help manufacturers and retailers keep track of inventory. They also give valuable ­information about the quantity of products being bought and, to some extent, the consumers buying them. These codes serve as product fingerprints made of machine-readable parallel bars that store binary code. Created in the early 1970s to speed up the check out process, though bar codes have a few disadvantages:

In order to keep up with inventories, companies must scan each bar code on every box of a particular product.

Going through checkout line involves same process of scanning each bar code on each item.

Bar code is a read-only technology, meaning that it cannot send out any information.

RFID tags are an improvement over bar codes because the tags have read and write capabilities. Data stored on RFID tags can be changed, updated and locked. RFID tags can signal their presence, unique identity, location and other user-defined info, in which reads are performed in milliseconds. Automatic (no human error), designed to replace the barcode ; No line of sight required and no physical contact (optical reader). It's a system of tags (transponder), readers (transceiver), antennas, software and backend network (electronic databases).

1.4.3 RFID Tags Past and Present

Inductively coupled RFID tags were powered by a magnetic field generated by the RFID reader. Electrical current has an electrical component and a magnetic component -- it is electromagnetic. Because of this, you can create a magnetic field with electricity, and you can create electrical current with a magnetic field. The name "inductively coupled" comes from this process -- the magnetic field inducts a current in the wire. Capacitive coupled tags were created next in an attempt to lower the technology's cost. These were meant to be disposable tags that could be applied to less expensive merchandise and made as universal as bar codes. Capacitive coupled tags used conductive carbon ink instead of metal coils to transmit data. The ink was printed on paper labels and scanned by readers.

Newer innovations in the RFID industry include active, semi-active and passive RFID tags. These tags can store up to 2 kilobytes of data and are composed of a microchip, antenna and, in the case of active and semi-passive tags, a battery. The tag's components are enclosed within plastic, silicon or sometimes glass.

At a basic level, each tag works in the same way:

Data­ stored within an RFID tag's microchip waits to be read.

The tag's antenna receives electromagnetic energy from an RFID reader's antenna.

Using power from its internal battery or power harvested from the reader's electromagnetic field, the tag sends radio waves back to the reader.

The reader picks up the tag's radio waves and interprets the frequencies as meaningful data.

Inductively coupled and capacitive coupled RFID tags aren't used as commonly today because they are expensive and bulky.

1.4.4 System Characteristics

Frequency of Operation :

Low Frequency (LF), data transfer rate is low and frequency ranges between 125 kHz - 134 kHz. Typical applications involve Access control and Animal tracking. High Frequency (HF), have medium data transfer rate and frequency range is, 13.56 MHz Mostly applied in Contact-Less Smartcards, libraries, Access Cards and Item Level tracking. Ultra High Frequency (UHF), since data transfer rate is high, less sensitive to environmental detuning. Frequency ranges between 860 MHz - 960 MHz Applications mostly involve tracking of Supply Chain. Microwave, have very high transfer rate, frequency ranges between 2.45 GHz - 5.8 GHz, but line of sight is required for long distance communication.

Fig 1.2 Classification based on Frequencies

Active, Semi-passive and Passive RFID Tags

Active and semi-passive RFID tags use internal batteries to power their circuits. An active tag also uses its battery to broadcast radio waves to a reader, whereas a semi-passive tag relies on the reader to supply its power for broadcasting. Because these tags contain more hardware than passive RFID tags, they are more expensive. Active and semi-passive tags are reserved for costly items that are read over greater distances -- they broadcast high frequencies from 850 to 950 MHz that can be read 100 feet (30.5 meters) or more away. If it is necessary to read the tags from even farther away, additional batteries can boost a tag's range to over 300 feet (100 meters).

Like other wireless devices, RFID tags broadcast over a portion of the electromagnetic spectrum. The exact frequency is variable and can be chosen to avoid interference with other electronics or among RFID tags and readers in the form of tag interference or reader interference. RFID systems can use a cellular system called Time Division Multiple Access (TDMA) to make sure the wireless communication is handled properly.

Passive RFID tags rely entirely on the reader as their power source. These tags are read up to 20 feet (six meters) away, and they have lower production costs, meaning that they can be applied to less expensive merchandise. These tags are manufactured to be disposable, along with the disposable consumer goods on which they are placed.

Another factor that influences the cost of RFID tags is data storage. There are three storage types: read-write, read-only and WORM (write once, read many). A read-write tag's data can be added to or overwritten. Read-only tags cannot be added to or overwritten -- they contain only the data that is stored in them when they were made. WORM tags can have additional data (like another serial number) added once, but they cannot be overwritten.

In order to implement low-power, low-complexity and highly secured RFID authentication system, since only passive tag get closer to reader and get enough inductive coupled energy from antenna. Because of its passive feature, tags in the market doesn't have enough security, the high security system may take larger area and power. In order to overcome the weakness of security, system should have strong encryption algorithms and authentication mechanisms that can withstand a variety of attacks.

Fig 1.3 Classification based on Powering Techniques

1.4.5 APPLICATIONS

While RFID technology has potential applicability in every industry, commerce, or service where data needs to be collected, commercial business sectors will be the focus for growth.

These commercial sectors include:

Transportation and Distribution

Fixed Asset Tracking, Aircraft, Vehicles, Rail Cars, Containers Equipment, Real-Time Location Systems

Retail and Consumer Packaging

Supply Chain Management, Carton Tracking, Pallet Tracking, Inventory Tracking, Pharmaceuticals

Industrial and Manufacturing

Tooling, Work-in-Progress

Security and Access Control

Airport and Bus Baggage, Employee Identification, Parking Lot Access, Anti-Counterfeiting,

Room, Laboratory, and Facility Access.

1.4.6 Authentication

High-security systems also require the interrogator to authenticate system users. In this very high-security example, the authentication procedure would probably be two-tiered, with part of the process occurring at the controller and part of the process occurring at the interrogator. There are basically two types of authentication. They are called mutual symmetrical and derived keys. In both of these systems, an RFID tag provides a key code to the interrogator, which is then plugged into an algorithm, or a "lock," to determine if the key fits and if the tag is authorized to access the system.

1.4.7 Data Encryption/Decryption

Data encryption is another security measure that must be taken to prevent external attacks to the system. Imagine that a third party were to intercept a user’s key. That information could then be used to make fraudulent purchases, just as in a credit card scam. In order to protect the integrity of data transmitted wirelessly, and to prevent interception by a third party, encryption is used. The interrogator implements encryption and decryption to do this. Encryption is also central to countering industrial espionage, industrial sabotage, and counterfeiting.

1.4.8 Security ATTACKS and Countermeasures

Unauthorized tag disabling

These are Denial-of-Service (DoS) attacks in which an attacker causes RFID tags to assume a state from which they can no longer function properly. This results in the tags becoming either temporarily or permanently incapacitated. Such attacks are often exacerbated by the mobile nature of the tags, allowing them to be manipulated at a distance by covert readers.

One way to prevent this is by having each tag share with the server a permanent (non-erasable) private identifying key ktag (another way, which is however not suitable for low-cost tags, would be to use public key cryptography). Then, when a tag is challenged by a reader, it will generate a response using this private key. it should be hard for an attacker to extract the private key from the tag’s response. For this purpose a cryptographic one-way function should be used.

Unauthorized tag cloning

These are integrity attacks in which an attacker succeeds in capturing a tag’s identifying information. Again these attacks are exacerbated by the fact that the tags can be manipulated by rogue readers. To defeat cloning attacks it should not be possible for an attacker to access a tag’s identifying data. Such data should be kept private. However for authentication, it should be possible for the back-end server to verify a tag’s response. The response must therefore corroborate (but not reveal!) the tag’s identifying data. This can be achieved by having the server share a private key ktag with each tag, as in the previous case.

Unauthorized tag tracking

These are privacy attacks in which the attacker can trace tags through rogue readers. Unauthorized tracking is based on tracing a tag responses to a particular tag. This can be prevented by making certain that the values of the responses appear to an attacker as random, uniformly distributed. In fact, since we are assuming that all entities of an RFID system have polynomialy bounded resources, it is sufficient for these values to be pseudo-random.

Replay attacks

These are integrity attacks in which the attacker uses a tag’s response to a rogue reader’s challenge to impersonate the tag. The main concern here is in the context of RFIDs being used as contactless identification cards (in substitution of magnetic swipe cards) to provide access to secured areas and/or resources. In such applications, RFIDs can be more vulnerable than other mechanisms, again due to their ability to be read at a distance by covert readers.

To deal with replay attacks the tag’s response must be unique for every server challenge. To achieve this, the values of the server challenges and the tag responses must be unpredictable. One way to achieve this is to enforce that the answers be (cryptographically) pseudo-random.

1.5 Need of Efficient Authentication Protocol

In order to implement low-power, low-complexity and highly secured RFID authentication system, since only passive tag get closer to reader and get enough inductive coupled energy from antenna. Because of its passive feature, tags doesn't have enough security, the high security system may take larger area and power. In order to overcome the weakness of security, system should have strong encryption algorithms and authentication mechanisms that can withstand a variety of attacks.

An RFID protocol requires at least two passes for (one-way) tag authentication: a challenge from the server and a response from the tag. If the tag initiates the protocol then we need at least three passes for secure tag authentication. For a minimalist approach one should aim for two passes. The cost of generating the tag response must also be minimal, if we take into account the severe restrictions on resources for tags.

2. LITERATURE SURVEY

2.1 OVERVIEW

The security research of RFID system is focused on how to solve information security problems between the tag and reader communication. Low-cost RFID tags are extremely limited in storage space. The cheapest tag's ROM is only 64-128bits.It only can accommodate a unique identifier. Also RFID tag s power supply and computing capacity are very limited. These limitations of the low-cost RFID system require the special requirements in security mechanism designing. The choices of security mechanisms are subject to many restrictions.

The RFID tag receives a query from the reader and transmits its own unique identification information(tag’s ID). The reader transmits the information to the back-end server, which verifies the value in order to authenticate the tag. In this process, communication between the tag and reader has the following characteristics,

The tag’s ID is transmitted to the reader via radio frequency communication, without any processing.

The tag transmits its own ID when there is a regular query in any reader.

Communication between a back-end server and reader is secure. Communication involving a reader and tag is insecure, because it is based on radio frequency.

These characteristics can cause serious information leakage in the RFID system. And the adversary can engage in various illegal behaviors by using the acquired information. The privacy violations occurring in RFID systems are divided into user privacy violation and location privacy violation.

User privacy violation : The adversary can analyze the output value of a specific RFID tag and

acquire the attached object information, which can be used to violate the user’s personal privacy.

Location privacy violation : Since a tag has always a unique unchangeable output value, the location of the user can be traced.

2.2 SECURITY THREATS

Eavesdropping: In principle, the RFID system cannot be perfectly free from the eavesdropping. Therefore, even if the adversary makes the eavesdropping, it should prevent the adversary from acquiring the tag’s ID, secret value, user's secret information or other information that can be used for other attacks.

Traffic analysis: Traffic analysis is an active attack. To prevent this attack, it should have the adversary not distinguish the secret information from other information among the information acquired through the eavesdropping. Or it should have the adversary consume so much time and cost as to give up the acquisition of information.

Location tracking: To prevent the location tracking, it is necessary to design the protocol to change the response of tag at every session by using the random number or so.

Replay attack: To be secure from the replay attack, the information transmitted by the tag should be changed at every session and it should be impossible to acquire the identification information of the tag from the transmitted information. Thus, even if the adversary has eavesdropped and saved all the communications between the tag and the reader of the previous sessions, it is impossible to generate a new value by using them to get the authentication from the reader.

Spoofing: It should be difficult for the adversary to disguise as a legitimate reader. The procedure for the reader to authenticate the tag is also necessary.

Physical attack: It is actually very hard to prevent the physical attack with the protocol. Therefore, a physical countermeasure is necessary against the physical attack.

Fig 2.1 Taxonomy of RFID Security

On the basis of countermeasure strategies, the security requirements equipped by the RFID system to protect the privacy violation and to prevent the forgery can be defined as follows: Confidentiality, Indistinguishability, Forward security, and Mutual authentication.

Confidentiality : Confidentiality is a security requirement that all the information should be secretly transmitted in every communication. If the tag freely gives the important information without authentication procedure or encrypt, the adversary can easily identify the tag or acquire the private information of tag owner. Therefore, for the security of confidentiality, it is necessary to authenticate the reader when the tag transmit the identification information to the reader, or to transmit the encrypt information in order only for the legitimate reader to read it.

Indistinguishability : It is the requisite that the transmitted information of the tag should not be same, expectable, nor distinguishable from the transmission information of other tag. If the transmitted information of the tag cannot satisfy the indistinguishability, the adversary with the same reader can continuously trace the owner of specific tag or detect the real time location of the tag owner by using the readers dispersed in several places.

Forward security : It is the requisite that the previously transmitted information should not be

traced with the present transmission information of the tag. If the past location of the specific tag owner can be traced with the present information, it will be a serious privacy infringement.

Mutual authentication : The mutual authentication is the requisite that the authentication should be given between the objects composing the RFID system. That is, the mutual authentication should be made between tag and reader, reader and back-end server, and tag and back-end server.

2.3 SECURITY PROPOSALS

RFID security proposals either based on Cipher-based protocols and Hash-based protocols. Lack of

computational resources is denoted as temporary state of affairs, but cost factor is still a problem since it is used in vast numbers. And if RFID replaces barcodes on individual items, they will substantially contribute cost of those items. This survey address security and privacy concerns of mutual authentication mechanism, during transmit from reader to tag and vice-versa. The System should be highly secured with authentication protocol which does anti-intrusion and encryption algorithm, that encrypts important data which cannot be decipher by attacker. The following figure 2.1 depicts security protocol types. The taxonomy of RFID security is shown in figure 2.2.

2.3.1 Cipher-based Authentication

1) Tiny Encryption Algorithm :

Abdelhalim et al [11], proposed a Modified Tiny Encryption Algorithm (MTEA) , using Linear Feedback Shift Register (LFSR) which overcomes the security weakness of TEA against equivalent key attacks. This system implements a Pseudo random Number Generator to improve the security strength of TEA, such as LFSR, where key is frequently changed in each round instead of a single symmetric key for all rounds like in standard TEA. Key of final round is used as key of first round in the decryption. By implementing different decryption keys, key secrecy is highly preserved in MTEA.

Fig 2.2 Classification of Security Protocols

2) Triple DES Algorithm :

Jianguo Hu et al [10], proposed a strong authentication for RFID system by implementing triple DES encryption algorithm on low cost passive RFID tag. To authenticate the legitimacy of both reader and tag, authors proposed unpredictable random key to replace authentication key, protect tag's key from being attacked. The key is generated using random number generator and predicted with a strong encryption algorithm. Random key can be generated at any time, so the system just transmit random number when need to authenticate. Can support 56-bit, 112-bit or 168-bit key length, thus provides enough security for the chip. Even the attacker acquires the authentication key, he gets nothing but some unpredictable number.

3) Advanced Encryption Standard, Challenge-Response Protocol

Tuan Anh Pham et al [12], proposed a mutual authentication based on symmetric block cipher AES-128, which overcomes the existing AES cryptographic proposals, where synchronization between the reader and the tag is lost if responsible from tag is blocked. A value seed 's' of each tag is stored on the server and on the rewritable memory of tag, which get automatically updated after each successful authentication. Since Ek(s) changes every authentication cycle, attackers can't utilize the former data, to delude the authorized reader or tag during authentication process. Thus overcome Replay Attack and Man-in-the-middle Attacks.

4) Stream Cipher Based OTP, Challenge-Response Protocol

Young Sil Lee et al [12], proposed a low-resource hardware implementation appropriate for efficient mutual authentication in RFID systems. The System is composed of a stream cipher based One-Time Password (OTP) by challenge-response pair of a Physically Unclonable Function (PUF) which overcomes the security weakness of key disclosure problem. This system implements NLM-128, Non-Linear Stream Cipher to generate the OTP value. This OTP can only be used once and user has to authenticated with a new password key each time. Thus overcomes eavesdropping and even attempting reply attack can't be succeed.

5) Backward Link Authentication

Behzad Malek et al [13], proposed a Backward Link Authentication based on McEliece Cryptosystem. Drawback is that this cryptosystem cannot be used directly in low-cost RFID tags due to large size of public key matrix. The modified system involves m-by-n Toeplitz matrix that can be stored by saving only m+n-1 elements of matrix, where storing total random m-by-n matrix, one would need all mn elements. In original McEliece the matrix S is selected as a totally random, invertible matrix in computing the public-key matrix F. Here, in modified cryptosystem the calculation of public-key matrix in such that it will be a sub-matrix of a bigger Toeplitz matrix.

6) HB+ Protocol

A solution to mutual authentication is exposed in Juels and Weis (2005), authors are inspired by the work in Hopper and Blum (2001) to introduce the HB+ protocol, a novel, symmetric authentication protocol with a simple, low-cost implementation. The security of the HB+ protocol against active adversaries is proved and based on the hardness of the Learning Parity with Noise (LPN) problem. The protocol is based on r rounds, where r is the security parameter, and each round requires the tag and the server to send a message |l| bits to each other, where |l| is the key length; to perform two inner product over terms of |l| bits.

7) Symmetric Key Cryptography

Damgard and Pedersen(2008) propose a model and definition for anonymous group identification that is well suited for RFID systems. Further, for the case where tags hold independent keys, they prove a conjecture by Juels and Weis, namely in a strongly private and sound RFID system using only symmetric cryptography, a reader must access virtually all keys in the system when reading a tag. This poses on a reader a lower bound of O(n) access to its local memory.

2.3.2 HASH - based Authentication

1) One-Way Hash based Authentication Protocol :

He Lei et al [10], proposed a hash based authentication using forward security. This mechanism overcomes de-synchronization attacks. In this system both tag and backend database update variables, key 'k', secret value shared with all tags and 'id' using hash operation. Even if an adversary interferes the communication after tag authenticates backend database successfully and updates its 'k' and 'id' stored, backend database can use previous 'k' and 'id' to authenticate tag and resynchronize those variables. This proposed system is suitable for low-cost RFID system on storage, communication and computation cost of tags.

2)Reader-Dependent Key Management, Three-Way Handshake Protocol :

Roberto Di Pietro and Refik Molva [11], devised a technique to make RFID identification server dependent, a different unique secret key shared by a tag and a server. A probabilistic tag identification scheme, requires the server to perform just bitwise operations, thus speeding up the identification process. The tag identification protocol assures privacy, security and resilience to DoS attacks. The identification protocol requires reader to access local database(DB) of tags’ keys O(n) times. RFID tag to store a single secret key for all servers yet assuring confinement property in case of server compromise.

3) Hash Chain based Tag Identification and Mutual Authentication :

Tsudik [06] and Rhee et al. [05], employed hash chains to allow tag identification and mutual authentication. The hash chain length corresponds to the lifetime of the tag stated in advance, leading to a waste of memory on the server side. System implies cryptographic hash function, which uses single key or password to produce several one-time keys, on order of h(x) to a string.

Molnar and Wagner [04], proposal requires just logδ n interactions between the server and a tag for the server to identify the tag is proposed. This approach requires logδ keys to be stored on each tag. This technique weakens the privacy when an adversary is able to tamper at least one tag. This system suffers from an expensive time complexity on server side, because only symmetric cryptographic functions can be used, server needs to explore its entire database in order to retrieve the identity of the tag it is interacting with.