Annotated Bibliography

4EHSbyEHS. “EMF Radio Blocking Fabrics.” Accessed 26 March 2014.

This website sells signal-blocking fabrics to the general public. Unlike most websites for those who are looking into signal-blocking items, this site sells the fabric itself rather than an item (such as a wallet or cell phone case) that is already made out of the fabrics. This is useful because the site also includes the compositions of the fabrics, providing the percentage and types of fabric used in the different styles of signal-blocking fabric. Including these differences makes it easier to understand the differences in signal-blocking capabilities based upon the fabric’s composition. Most importantly, the site includes the percentage of the frequency that is blocked by the fabric, illustrating that these fabrics do not completely block the signals, but reduce them significantly depending on what metals are included in the production.

Atherton, Kelsey. “Hide From GPS With This Signal-Blocking Phone Case.” Popular Science, 6 August 2013. Accessed 26 March 2014.

 Kelsey Atherton discusses the Kickstarter campaign’s Off Pocket: signal blocking or faraday fabric fashioned to block cellular, Wi-Fi, and GPS signals to and from cell phones.This is one of the many products of this kind to be created for this purpose. The company Kickstarter was founded by technologist Adam Harvey and fashion Designer Johanna Bloomfield to create a fashionable and foolproof way of protecting data coming from and to mobile devices. The article explains how signal-blocking fabric works and is tested, as well as the practical applications. Atherton also covers the current consumer products currently and previously available using signal-blocking fabric.

Chen, C. L., Chen, Y. Y., Huang, Y. C., Liu, C. S., Lin, C. I., & Shih, T. F. “Anti-counterfeit ownership transfer protocol for low cost RFID system,” WSEAS Transactions on Computers 7 (2008): 1149-1158. Accessed 11 March 2014.

 RFID is a new technology with many new associated security concerns. Chen et al. review previous solutions to RFID counterfeit, such as the Koh et al. “track and trace” solutions. But, not all these solutions confirm to current standards. They propose an anti-counterfeit ownership transfer protocol for a low cost RFID system. Ultimately, this source is valuable to our project and others interested in RFID security as it relates to the OFF Pocket and similar projects for the review of RFID as a technology and for the general information regarding security concerns relating to RFID tags.

Clifford, Stephanie, and Quentin Hardy. “Attention, Shoppers: Store Is Tracking Your Cell.” The New York Times, 14 July 2013. Accessed 17 February 2014.

 Stephanie Clifford and Quentin Hardy help to provide evidence for how signal blocking technology can have practical implications in today’s shopping experience. In an attempt to make off-line shopping more user friendly and on-line comparable, Nordstrom, and many other stores, have started installing Wi-Fi tracking devices in their stores that cannot only recognize when you enter the store (and if you have been there before) but where in the store you go and how much time you spend in a location. The purpose of this is to make your shopping experience more similar to sites like Amazon, which can remember your searches, recommend products and tailor your shopping experience to the individual. Although it is accepted by many online shoppers, this can be considered invasive by off-line shoppers, even when properly informed by signs outside  and inside of the stores. This is just one of many real and increasingly popular reasons for the use of signal blocking fabric.

How Stuff Works. “How Faraday Cages Work.” Accessed 26 March 2014.

This article will be useful for our research as it presents an easy-to-comprehend explanation of how a Faraday cage works. Faraday cages create an electric shield that prevents signals from being emitted through the cage. The concept of a Faraday cage is the basis for how RFID signal-blocking fabrics work, as the fabrics insulate the devices with RFID chips and create a Faraday cage. It is essential for our project that we have an understanding of how a Faraday cage works and why this is important for the concept of signal-blocking fabrics. The article also gives insight into other ways in which Faraday cages exist in the modern world, giving context to the content of our research.

Invisibler. “Stop Cellphone Tracking with SilentPocket.” Last modified 24 October 2013.

 Author andre overviews the SuitPocket, a cellphone case constructed of signal-blocking fabric, and considers its features. It reviews both features of use (e.g. ease of use, leather construction) and function (e.g. it lists the many types of signals which are blocked by the product: RFID, NFC, GPS, CDMA, GSM, 3G/4G/LTE, Bluetooth, “and any other”). It cites an interview with Binney, a National Security Agency veteran, to discuss how the NSA and similar agency may construct complex social graphs of cell users (and those who carry and use similar devices) regardless if the person is a citizen, foreign national, or has committed a crime.

Juels, A., & Weis, S. A. “Defining Strong Privacy for RFID,” ACM Transactions on Information and System Security 13 (2009): 7-26. Accessed 11 March 2014.

 “Defining Strong Privacy for RFID” offers new definitions privacy as applicable to RFID systems and multi-verifier systems as applied in the real world. Juels and Weis examine several new and current privacy-enhancing protocols, and note that these systems do not meet their new, simple definitions of privacy in these context and so are exposed to potential vulnerabilities. Additionally, they analyze and suggest improvements for “Hash-Locks”,  one of the first such protocols in the literature. They conclude that improved definitions are needed to capture the real-world applications of RFID encryptions and protection: either stronger definitions or weaker (but more practical and useful) definitions of privacy are needed. Ultimately, this source is primarily concerned with cryptography as it relates to RFID privacy and security, and so provides important contextual and background information but is not widely applicable to the everyday user of signal-blocking fabrics.

Kickstarter. “The Ultimate, RFID Blocking, Minimalist Wallet.” Accessed 26 March 2014.

 “The Ultimate, RFID Blocking, Minimalist Wallet” is a product similar to the OFF Pocket and Silent Pocket. This kickstarter wallet is made in the UK and so primarily designed with RFID tags in credit and debit cards in mind, however the site notes that the wallet may also block cell signals (e.g., the site claims that by placing the wallet in between the user and the phone in the users pocket, concerned cell phone users may be able to reduce signals which pass through them). The wallet is lined with Cryptalloy® sheilding foil, which the article notes is more effective than either aluminum foil and copper/zinc at blacking RFID reading on all common frequencies. A small amount of information about identity theft is also provided, including the observation that identity thefts have increased by ~5 million since 2007.

Kitchen, Michael William. Electromagnetic shielding carrying case for contactless smartcards and personal articles. US Patent 7830672 B1, filed 27 June 2008, and issued 29 November 2010.

 This patent describes the technical components of a non-fabric electromagnetic shielding carrying case, a similar product to OFFpocket but consisting entirely of metal. This reference has detailed diagrams of the dimensions of the carrying case and mentions other solutions for blocking radio frequencies and other signals, particularly “conventional leather and fabric bi-fold wallets.” This citation also mentions four problems with wallets like these, such as tendency for the fabric to “pivot” and allow for unintentional RF scanning and a claim that the shielding liner or material in fabric products tends to be flimsy and unreliable. For our purposes, these criticisms of signal-blocking fabric should be taken into account. The reference concludes with a summary, ramification, and scope of the invention and how it can fit into users’ lives.

Lehpamer, Harvey. RFID Design Principles Second Edition (Norwood, Massachusetts: Artech House, 2012). 

This book serves as a valuable source because it details the purpose, function, and design of radio frequency identification devices. Since we are studying fabrics that block RFID signals it is essential to have an understanding of how these signals work prior to researching how the signals can be blocked and why someone would want to block the signals. While the entire book will not be helpful, the source from which we found the book highlights the sections which are of particular importance for our research and therefore will likely be the areas of the book in which we focus our use of the source. Specifically, the book has an entire chapter devoted to the sociocultural implications of RFID and the applications which use RFID tracking.

Lerman, Jonas. “Big Data and Its Exclusions.” Stanford Law Review 66.55 (2013): 55-63. 17 February 2014.

 This law review essay takes a different look at the way big data is viewed. While most essays and articles focus on how big data reduces privacy by going into the daily lives of people, this essay focuses on those who are not a part of big data, including those who do not have access to the types of technology that are tracked in order to create big data. While this essay does not address signal-blocking fabrics, it addresses the effects of people not being “on the grid,” which is exactly what those who use signal-blocking fabrics are attempting to be. The essay illustrates how big data excludes them and how these exclusions affect decisions and changes that will be made without the valuable knowledge missing from those who are off the grid.

Merchant, Brian. “Motherboard.” Motherboard. N.p., 28 Jan. 2013. Web. 17 Feb. 2014.

 This article provides us with insight into a way that big data is being used in order to make positive advances in the world. While it does not specifically discuss the signal-blocking fabrics that we are studying, it discusses one of the many types of data collection that these fabrics block if they are used. The article discusses how IBM is using big data to improve public transit by tracking peoples’ movement habits while allegedly keeping their private information secure. Unlike a lot of big data collection that is seen as an invasion of privacy, this article takes a positive spin on big data while providing a caution that it is necessary to ensure privacy as well.

Narayanaswamy, G.; Jagannatha, S.K.; Engels, D.W. “Blocking Reader: Design and implementation of a low-cost passive UHF RFID Blocking Reader.” Paper presented at IEEE International Conference on RFID, 14-16 April 2010.

This paper, presented at a conference that highlights emerging technologies, discusses another type of RFID signal-blocking technology. The paper focuses on the RFID Blocking Reader, a device that can be carried around and used to protect individuals from having their technologies with RFID chips read against their will. The device creates a Faraday cage, similar to the signal-blocking fabrics, however it is allegedly a much larger area because it stops the readers within several feet. This article is useful as it provides other ways in which RFID signals are able to be blocked by technological advances.

Ohm, Paul. “The Underwhelming Benefits of Big Data.” University of Pennsylvania Law Review 2013. 17 February 2014.

 This submission, a response to a previously published article, in the Penn Law Review examines the different uses of big data, collected from RFID chips and other sources. While addressing the positive aspects of big data, such as creating improvements in medicine, climate, food safety, and business, it mainly covers the negative aspects of this. Of major concern for the author is the invasion into what is perceived as a private space as big data collection increases. The author admits that this is type of collection is here to stay but that it is important to know that there are several underlying, possibly negative, consequences to allowing this perceived invasion of privacy in our lives. The response also notes that the positive consequences may be overstated by advocates of big data in their support of continuing these practices.

Rieback, M., Crispo, B., Tanenbaum, A. “RFID Guardian: A Battery-Powered Mobile Device for RFID Privacy Management,” ACISP 2005, LNCS 3574, pp. 184-194. Accessed 30 March 2014.

This book chapter is about a proposed technology, an “RFID Guardian,” that operates quite differently from signal-blocking fabrics but achieves a similar type of privacy. The RFID Guardian is a theoretical mobile device that tracks the frequency that is occurring around a user. The user will be able to tell what kind of information is being sent via RFID and what type of information is being collected by RFID readers. This helps the user know if their personal information is being used for anything illicit or illegal. While this does not discuss the technology of signal-blocking fabrics that we are studying, it is very helpful in that it addresses the other ways in which people are attempting to address the privacy issues surrounding RFID technologies. This will be helpful in discuss the social implications of the technology.

Roberts, C.M. “Radio Frequency Identification (RFID),” Computers and Security (2006): 18-26. Accessed 30 March 2014.

This source provides a significant amount of background necessary for conducting research on signal-blocking fabrics. In order to fully understand how signal-blocking fabrics work it is necessary to have a full understanding of how radio frequency identification (RFID) works because these are the signals being blocked by the fabrics. This source is a comprehensive overview of how RFID works and therefore will be an excellent way for us to understand the intricacies of these radio waves. While it does not address signal-blocking fabrics at all, this source still provides immense value because of its explanatory power regarding RFID technology.

Srinivasan, S., Aggarwal, A., & Kumar, A. “RFID Security and Privacy Concerns,” WSEAS Transactions on Communications 5 (2006): 296-301. Accessed 11 March 2014.

 This article is one of the earlier sources we have on RFID sociotechnical issues and briefly discusses the history of RFID technology, its capabilities, and its impacts on privacy and security. The article provides a quick overview of the RFID system (consisting of a transponder, reader, and antenna) and the types of RFID tags (active, passive, semi-passive). It discusses the benefits of RFID for both businesses and consumers and identifies specific use cases such as automobile toll responders, retail shopping, E-passports, tagged pets, smart appliances, and healthcare. Finally, the article discusses privacy concerns such as confidentiality of data, the notion that RFID-tracked data could be used to discriminate or target individuals, and the idea that products could be tracked beyond when they left the store and into a person’s private property. The article offers several ways to counter these security concerns, such as encrypting tags for confidentiality, deactivating tags automatically after a sale is made, and “skimming fabric” as an easily available option to the user who could then hide the tag.

Yao, W., Chu, CH., Li, Z. “The Adoption and Implementation of RFID Technologies in Healthcare: A Literature Review,” Journal of Medical Systems 36 (2012): 3507-3525. Accessed 11 March 2014.

 While this article focuses on surveying RFID technology adoption in healthcare, the discussion on Critical Success Factors for technology adoption is useful for understanding pro-RFID arguments and perceived benefits of RFID tagging (at least in healthcare). RFID technology is suggested as an efficient and cost-effective alternative to fie common problems in healthcare failures: medical mistakes, increasing cost, theft loss, drug counterfeiting, and inefficient workflow. Functions that the technology fulfills are: tracking (i.e. equipment), identification and verification (namely of patients), sensing (for logistics and biometrics), interventions (e.g., automated care, improving procedures), and alerts and triggers (primarily patients during dangerous events, e.g. surgery). Suggestions for successful technological adoption are split into strategic and tactical factors. Strategic factors focus on the top-level having a clear objective and vision, carefully considering privacy, and choosing reliable vendors. Tactical factors are more detailed and include starting with a small and customized project, integrating into the existing information technology infrastructure, and having effective communication throughout.

YouTube. “SHIELDON RF BLOCKING Fabrics (128,225,240).” Accessed 26 March 2014.

This video demonstrates how a specific brand of signal-blocking fabrics, Shieldon, significantly lowers the frequency of signals emitted from the device. While the video does not provide the viewer with specific details on how the fabric lowers these rates or if the rates would be different if the fabrics were aligned in a different way, the video clearly demonstrates the large change in frequency that takes place when the fabric is put in between the device emitting the radio signal and the signal reader. The video uses several different types of fabrics–labeling each in the video when used–which is helpful because the viewer can then go to the company’s website to see the specifications of each type of fabric used to see which are the most effective at blocking emitted signals, which can be determined because the video shows the reading for the device before and after each fabric is applied as a barrier.


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