Josef Scharinger

NFC Devices: Security and Privacy

The aim of this paper is to show security measures for NFC (Near Field Communication) use cases and devices. We give a brief overview over NFC technology and evaluate the implementation of NFC in devices. Out of this technology review we derive different use cases and applications based on NFC technology. Based on the use cases we show assets and interfaces of an NFC device that could be a possible target of an attacker. In the following we apply different attacks against the operation modes to show how applications and devices could be protected against such attacks. The information collected is consolidated in a set of threats giving guidelines on how to improve security and overcome privacy issues. This allows integrating NFC technology in a secure way for the end consumer.

Fast encryption of image data using chaotic Kolmogorov flows

To guarantee security and privacy in image and video archival applications, efficient bulk encryption techniques are necessary which are easily implementable in soft- and hardware and are able to cope with the vast amounts of data involved. Experience has shown that block-oriented symmetric product ciphers constitute an adequate design paradigm for resolving this task, since they can offer a very high level of security as well as very high encryption rates. In this contribution we introduce a new product cipher which encrypts large blocks of plaintext by repeated intertwined application of substitution and permutation operations. While almost all of the current product ciphers use fixed (predefined) permutation operations on small data blocks, our approach involves parametrizable (keyed) permutations on large data blocks (whole images) induced by specific chaotic systems (Kolmogorov flows). By combining these highly unstable dynamics with an adaption of a very fast shift register based pseudo-random number generator, we obtain a new class of computationally secure product ciphers which offer many features that make them superior to contemporary bulk encryption systems when aiming at efficient image and video data encryption.

Managing an NFC Ecosystem

Whereas several NFC trials are already established around the world, currently there are no mass rolls out yet. This is due to several technical as well as administrative issues that have to be dealt with before rolling out such a system. In this paper we present an approach for managing the B2B relations in an near field communication (NFC) ecosystem offering services based on card emulation like loyalty, payment and ticketing. Out of experiences made from trials we show which services are needed in order to manage such an ecosystem and to provide convenience to the user. Further more we discuss functional aspects of such an ecosystem, the parties involved as well as their benefit for participating. Although the technology already given allows a smooth interaction for the consumer, the infrastructure behind the scene is complex and requires the cooperation on different levels to ensure interoperability and a thriving contactless scheme to be deployed.

The benefit of using SIM application toolkit in the context of near field communication applications

NFC is one of the most promising technologies in handsets for business applications like ticketing or payment. Actually those applications require a secure store for keeping sensitive data. Using the SIM card as a removable secure element for proximity applications is one option. We will elaborate a comprehensive study on the requirements and impacts of using the SIM card as a secure store for proximity applications, presenting the pros and cons of combining NFC with the SIM card in handsets. Based on these facts we worked out a concept and necessary processes for an NFC ecosystem based on a SAM. Hence we line out two different approaches for managing applications in the secure element. Finally the effects of this implementation on mobile network operators and application providers as well as consumers are summarized.

Applying relay attacks to Google Wallet

The recent emergence of Near Field Communication (NFC) enabled smart phones resulted in an increasing interest in NFC security. Several new attack scenarios, using NFC devices either as attack platform or as device under attack, have been discovered. One of them is the software-based relay attack. In this paper we evaluate the feasibility of the software-based relay attack in an existing mobile contactless payment system. We give an in-depth analysis of Google Wallets credit card payment functionality. We describe our prototypical relay system that we used to successfully mount the software-based relay attack on Google Wallet. We discuss the practicability and threat potential of the attack and provide several possible workarounds. Finally, we analyze Googles approach to solving the issue of software-based relay attacks in their recent releases of Google Wallet.

Practical Attack Scenarios on Secure Element-Enabled Mobile Devices

Near Field Communications card emulation mode is a way to put virtual smart cards into mobile phones. A recently launched application is Google Wallet. Google Wallet turns a phone into a credit card, a prepaid card and a tool to collect gift certificates and discounts. Card emulation mode uses dedicated smart card chips, which are considered to fulfill high security standards. Therefore, card emulation mode is also considered to be safe and secure. However, an NFC-enabled mobile phone introduces a significantly different threat vector. Especially a mobile phones permanent connectivity to a global network and the possibility to install arbitrary applications onto smart phones open up for several new attack scenarios. This paper gives an overview of the new risks imposed by mobile connectivity and untrusted mobile phone applications. The various APIs for secure element access on different mobile phone platforms and their access control mechanisms are analyzed. The security aspects of mobile phones are explained. Finally, two practical attack scenarios, a method to perform a denial of service (DoS) attack against a secure element and a method to remotely use the applications on a victims secure element without the victims knowledge, are highlighted.

Active perception and scene modeling by planning with probabilistic 6D object poses

This paper presents an approach to probabilistic active perception planning for scene modeling in cluttered and realistic environments. When dealing with complex, multi-object scenes with arbitrary object positions, the estimation of 6D poses including their expected uncertainties is essential. The scene model keeps track of the probabilistic object hypotheses over several sequencing sensing actions to represent the real object constellation.

Security Vulnerabilities of the NDEF Signature Record Type

The NFC Forum has released a first candidate for their Signature Record Type Definition. This specification adds digital signatures to the NFC Data Exchange Format (NDEF), which is a standardized format for storing formatted data on NFC (Near Field Communication) tags and for transporting data across a peer-to-peer links between NFC devices. With an increasing number of applications of the NFC and NDEF technology, more and more security threats became apparent. The signature record type is supposed to increase security for NDEF application by providing authenticity and integrity to the NDEF data. This paper takes a close look on the recently published Signature Record Type Definition and discusses its various security aspects. First, we introduce the signature record type and its usage. After that, we analyze the security aspects of the current signature method. Finally, we disclose multiple security vulnerabilities of the current Signature Record Type Definition and propose measures to avoid them.

Accuracy of a P300 Speller for People with Motor Impairments: a Comparison

A Brain-Computer Interface (BCI) provides a completely new output pathway that can provide an additional option for a person to express himself/her self if he/she suffers a disorder like amyotrophic lateral sclerosis (ALS), brainstem stroke, brain or spinal cord injury or other diseases which impair the function of the common output pathways which are responsible for the control of muscles. For a P300 based BCI a matrix of randomly flashing characters is presented to the participant. To spell a character the person has to attend to it and to count how many times the character flashes. Although most BCIs are designed to help people with disabilities, they are mainly tested on healthy, young subjects who may achieve better results than people with impairments. In this study we compare measurements, performed on people suffering motor impairments, such as stroke or ALS, to measurements performed on healthy people. The overall accuracy of the persons with motor impairments reached 70.1% in comparison to 91% obtained for the group of healthy subjects. When looking at single subjects, one interesting example shows that under certain circumstances, when it is difficult for a patient to concentrate on one character for a longer period of time, the accuracy is higher when fewer flashes (i.e., stimuli) are presented. Furthermore, the influence of several tuning parameters is discussed as it shows that for some participants adaptations for achieving valuable spelling results are required. Finally, exclusion criteria for people who are not able to use the device are defined.

Management of Multiple Cards in NFC-Devices

Near Field Communication (NFC) currently is one of the most promising technologies in handsets for contactless applications like ticketing or payment. These applications require a secure store for keeping sensitive data. Combining NFC with integrated smartcard chips in a mobile device allows the emulation of different cards. Representing each secure element with different UIDs poses several problems. Thus we propose an approach with a fixed UID dedicated to a Secure Element Controller (SEC). This approach allows an optimized backwards compatibility to already established reader infrastructures but also the communication in peer-to-peer mode with other NFC devices. Additionally the communication over peer-to-peer as well as the internal mode of secure elements at the same time is possible. This is approach poses a flexible alternative to the implementations proposed so far. In addition when there are to multiple, removable secure elements in a device it is ensured that the secure elements are only used by authorized user/devices. The SEC in this case handles the communication between the secure elements as well as their authentication.