RFID tags have very promising applications in many domains (retail, rental, surveillance, medicine to name a few). Unfortunately the use of these tags can have serious implications on the privacy of people carrying tagged items. Serious opposition from consumers has already thwarted several trials of this technology. The main fears associated with the tags is that they may allow other parties to covertly collect information about people or to trace people wherever they go. As long as these privacy issues are not resolved it will not be possible to reap the benefits of these new applications.

Radio Frequency Identification (RFID) systems aim to identify objects in open environments with neither physical nor visual contact. They consist of transponders inserted into objects, of readers, and usually of a database which contains information about the objects. The key point is that authorised readers must be able to identify tags without an adversary being able to trace them. Traceability is often underestimated by advocates of the technology and sometimes exaggerated by its detractors. Whatever the true picture, this problem is a reality when it blocks the deployment of this technology and some companies, faced with being boycotted, have already abandoned its use. Using cryptographic primitives to thwart the traceability issues is an approach which has been explored for several years. However, the research carried out up to now has not provided satisfactory results as no universal formalism has been defined. In this paper, we propose an adversarial model suitable for RFID environments. We define the notions of existential and universal untraceability and we model the access to the communication channels from a set of oracles.

Unique and challenging security problems arise due to the scarcity of computational, storage, and power resources in the low-cost pervasive computing environment. Particularly relevant examples of resource-constrained systems are low-cost Radio Frequency Identification (RFID) systems. Surprisingly, the computational abilities of low-cost pervasive devices like RFID tags are similar to another pervasive, weak computing "device": people.

Abstract. Authentication has an important role in many RFID applications for providing security and privacy. In this paper we focus on investigating how RFID can be used in product authentication in supply chain applications and a review of existing approaches is provided. The different categories of RFID product authentication approaches are analyzed within the context of anticounterfeiting and fields where future research is needed are identified. 1

Abstract. We propose a protocol that can be used between an RFID tag and a reader to exchange a secret without performing any expensive computation. Similarly to the famous blocker tag suggested by Juels, Rivest, and Szydlo, our scheme makes use of special tags that we call noisy tags. Noisy tags are owned by the reader’s manager and set out within the reader’s field. They are regular RFID tags that generate noise on the public channel between the reader and the queried tag, such that an eavesdropper cannot differentiate the messages sent by the queried tag from the ones sent by the noisy tag. Consequently, she is unable to identify the secret bits that are sent to the reader. Afterwards, the secret shared by the reader and the tag can be used to launch a secure channel in order to protect communications against eavesdroppers. It can also be used to securely refresh a tag’s identifier by, for example, xoring the new identifier with the exchanged secret key. Refreshing tags ’ identifiers improves privacy since it prevents tracking tags. 1

In this paper, we investigate the possible privacy and security threats to RFID systems, and consider whether previously proposed RFID protocols address these threats. We then propose a new authentication protocol which provides the identified privacy and security features and is also efficient. The new protocol resists tag information leakage, tag location tracking, replay attacks, denial of service attacks, backward traceability, forward traceability (under an assumption), and server impersonation (also under an assumption). We also show that it requires less tag-side storage and computation than other similarly structured RFID protocols.

Radio Frequency Identification (RFID) is an increasingly popular technology that uses radio signals for object identification. Successful object identification is the primary objective of RFID technology (after all, the last two letters of the acronym “RFID ” stand for “identification”). Yet, a recent major study by Wal-Mart has shown that object detection probability can be as low as 66%. In this paper we address the fundamental issue of improving object detection by tagging objects with multiple tags. This confirms for the first time the practicality and efficacy of previous works on multi-tag RFID systems. Using different configurations of commercial RFID equipment, we show significant improvements in object detection probability as the number of tags per object increases. We compare various combinations of multi-tags, readers, and antennas, and demonstrate that adding multi-tags to a system can improve object detection probabilities more dramatically than adding more readers. We also address issues such as tag orientation and variability, effects of multi-tags on anti-collision algorithms and on object detection in presence of metals and liquids, as well as the economics of multi-tags.

The design of ultralightweight authentication protocols that conform to low-cost tag requirements is imperative. This paper analyses the most important proposals (except for those based in hard problems such as the HB [1–3] family) in the area [4–6] and identifies the common weaknesses that have left all of them open to various attacks [7–11]. Finally, we present Gossamer, a new protocol inspired by the recently published SASI scheme [13], that was lately also the subject of a disclosure attack by Hernandez-Castro et al. [14]. Specifically, this new protocol is designed to avoid the problems of the past, and we examine in some deep its security and performance.

Abstract. Radio Frequency Identification (RFID) systems aim to identify objects in open environments with neither physical nor visual contact. They consist of transponders inserted into objects, of readers, and usually of a database which contains information about the objects. The key point is that authorised readers must be able to identify tags without an adversary being able to trace them. Traceability is often underestimated by advocates of the technology and sometimes exaggerated by its detractors. Whatever the true picture, this problem is a reality when it blocks the deployment of this technology and some companies, faced with being boycotted, have already abandoned its use. Using cryptographic primitives to thwart the traceability issues is an approach which has been explored for several years. However, the research carried out up to now has not provided satisfactory results as no universal formalism has been defined. In this paper, we propose an adversary model suitable for RFID environments. We define the notions of existential and universal untraceability and we model the access to the communication channels from a set of oracles. We show that our formalisation fits the problem being considered and allows a formal analysis of the protocols in terms of traceability. We use our model on several well-known RFID protocols and we show that most of them have weaknesses and are vulnerable to traceability.

Abstract. RFID-tags can be seen as a new generation of bar codes with added functionality. They are becoming very popular tools for identification of products in various applications such as supply-chain management. The widespread deployment of RFID technology will depend to a large extent on its acceptance by the general public. Thus, developing privacy and security technologies specifically suited to the constrained environment of RFID tags continues to be a key problem. In this paper, we introduce several new mechanisms that are cheap to implement or integrate into RFID tags and that at the same time enhance the security of the tags and the privacy of the individual carrying the tags. These new mechanisms are based on physical principles alone or on their combination with cryptographic methods. We also review previous works that use physical principles to provide security and privacy in RFID systems.