The IoT is innovative and important phenomenon prone to several services and applications, but it should consider the legal issues related to the data protection law. However, should be taken into account the legal issues related to the data protection and privacy law. Technological solutions are welcome, but it is necessary, before developing applications, to consider the risks which we cannot dismiss. Personal data is a value. In this context it is fundamental to evaluate the legal issues and prevent them, adopting in each project the privacy by design approach. Regarding the privacy and security risks, there are some issues with potential consequences for data and liability. The IoT system allows us to transfer data on the Internet, including personal data. In this context, it is important to consider the new European General Data Protection Regulation (GDPR) that will be in force on 25 May 2018. The GDPR introduces Data Protection Impact Assessment (DPIA), data breach notification and very hard administrative fines in respect of infringements of the Regulation. A correct law analysis allows evaluating risks preventing the wrong use of personal data. The contribution describes the main legal issues related to privacy and data protection focusing on the Privacy by Design approach, according to the GDPR. Furthermore, I resolutely believe that is possible to develop a global privacy standard framework that organisations can use for their data protection activities.
The purpose of this article is to discuss the application of blockchain technology in e-government, particularly in the Chinese context. Chancheng District, part of Foshan City in Guangdong Province, China, has undertaken a project called "The Comprehensive Experimental Area of Big Data in Guangdong Province" since 2016. Promoting the application of blockchain technology in e-government is an essential part of this undertaking, which is the first use of blockchain in government in China. Taking Chancheng's project as a case study, this article analyzes the framework, difficulties and challenges of applying blockchain to e-government at present, and discusses how blockchain technology can contribute to the development of e-government and public services in China. This article considers the practical realities in China and discusses the application of blockchain technology in Chinese e-government, finding that blockchain technology can bring the following benefits: (1) improvements in the quality and quantity of government services, (2) greater transparency and accessibility of government information, (3) development of information-sharing across different organizations, and (4) assistance in building an individual credit system in China. However, information security, cost and reliability are still major problems in application. Thus, establishing a general application platform of blockchain technology and developing management standards are crucial for promoting and applying blockchain in e-government. Blockchain provides an effective way of making government services more efficient, but standardizing the management system, processes and responsibility for the application is necessary for its further promotion. This article, by providing an analysis of the practice of blockchain in e-government in China, could serve as a foundation for further practical work and theoretical research in government services.
Jun 1, 2017·2017 IEEE International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData)
The IoT is innovative and important phenomenon prone to several services ad applications, but it should consider the legal issues related to the data protection law. However, should be taken into account the legal issues related to the data protection and privacy law. Technological solutions are welcome, but it is necessary, before developing applications, to consider the risks which we cannot dismiss. Personal data is a value. In this context is fundamental to evaluate the legal issues and prevent them, adopting in each project the privacy by design approach. Regarding the privacy and security risks, there are some issues with potential consequences for data security and liability. The IoT system allows us to transfer data on the Internet, including personal data. In this context, it is important to consider the new European General Data Protection Regulation (GDPR) - already in force from 24 May 2016 - that will be applicable on 25 May 2018. The GDPR introduces Data Protection Impact Assessment (DPIA), data breach notification and very hard administrative fines in respect of infringements of the Regulation. A correct law analysis allows evaluating risks preventing the wrong use of personal data. The IoT ecosystem is evolving quickly, developing several applications in different sectors. The main topics for the last time are Big Data and the blockchain. People are paying attention to the latest one because of its potential concrete use for services and applications, increasing the security measures to guarantee a secure system. However, it is equally important to analyse the legal issues related to them. Everyone has the right to the protection of personal data concerning him or her. In this context, we cannot dismiss to guarantee an adequate protection of personal data designing any application. The contribution describes the main legal issues related to privacy and data protection especially regarding the blockchain, focusing on the Privacy by Design approach, according to the GDPR. Furthermore, I resolutely believe that is possible to develop a worldwide privacy standard framework that organisations can use for their data protection activities.
Shinsaku Kiyomoto, Mohammad Shahriar Rahman, Anirban Basu
In this paper, we design a distributed platform for anonymized dataset trading without any centralized trusted third party. The platform consists of peers and consensus-based blockchain mechanism, and each peer acts as a data broker, data receiver, or verifier for blockchain in a data transfer transaction. A data broker collects data from data owners under their consent for data trading. The Privacy Policy Manager (PPM) manages the consent information and confirms them on behalf of data owners, when data distribution is requested from data broker. We implement a prototype system of the platform using an open-source blockchain mechanism, Hyperledger Fabric, and provide evaluation results of the prototype system.
We present the first measurement study of JoinMarket, a growing marketplace for more anonymous transfers in the Bitcoin ecosystem. Our study reveals that this market is funded with multiple thousand bitcoins and generated a turnover of almost 29.5 million USD over the course of 13 months. Assessing the resilience of the market against a well-funded attacker, we discover that in a typical scenario, a selective attack with a 90% success rate requires an investment of 14 000–54 000 USD (which is recoverable after the attack). We present economic arguments to explain the existence of this novel market for anonymity and underpin the hypothesis of heterogeneous time preference with empirical data.
The trend of digital currencies is catching fire these days, more and more people want to use digital currency. When we talk about digital currencies then how can we forget taking the name of Cryptocurrencies like Bitcoin. These currencies because of their P2P nature have won lot of hearts. You must have heard that "Every Rose has a thorn", similar type of thing is with Cryptocurrencies too. Because of the reason these currencies are P2P nature and there is no 3rd party who controls these cryptocurrencies, these are being used for illegal drugsarms dealing and for purchasing weapons online which are used in the terror attacks. We have found out a solution in order to put an end to it and the solution is Freezing of Assets. In this the owner will have the liberty to freeze any account whichever seem fishy and the freezed accounts will have their money intact, just the difference will be that they won't be able to transfer the money.
Bitcoin is a cryptocurrency which has received increasing interest over the last five years. Built upon a decentralized peer to peer system, it supports transparent, fast, cost effective, and irreversible transactions, without the need for trusting third party financial institutions. We know however little about people's motivation and experience with bitcoin currency. This paper reports on interviews with 20 bitcoin users in Malaysia about their experience and trust challenges. Findings show that bitcoins are used more as store of value for speculative investment or savings' protection. The paper advances the HCI theories on trust by identifying main bitcoin characteristics and their impact on trust, such as decentralization, unregulation, embedded expertise, and reputation, as well as transactions' transparency, low cost, and easiness to complete. We discuss insecure transactions, the risk of dishonest traders and its mitigating strategies. The paper concludes with design implications including support for the transparency of two-way transactions, tools for materializing trust, and tools for supporting reversible transactions.
In this paper, we present ethnographic data that unpacks the everyday work of some of the many infrastructuring agents who contribute to creating, sustaining and growing the Blockchain information infrastructure. We argue that this infrastructuring work takes the form of entrepreneurial actions, which are self-initiated and primarily directed at sustaining or increasing the initiator's stake in the emerging information infrastructure. These entrepreneurial actions wrestle against the affordances of the installed base of the Blockchain infrastructure, and take the shape of engaging or circumventing activities. These activities purposefully aim at either influencing or working around the enablers and constraints afforded by the Blockchain information infrastructure, as its installed base is gaining inertia. This study contributes to our understanding of the purpose of infrastructuring, seen from the perspective of heterogeneous entrepreneurial agents. It supplements existing accounts of the "when" and "how" of infrastructure, with a lens for examining the "why" of infrastructure.
Malte Möser, Kyle Soska, Ethan Heilman, Kevin Lee · 11 authors
Abstract Monero is a privacy-centric cryptocurrency that allows users to obscure their transactions by including chaff coins, called “mixins,” along with the actual coins they spend. In this paper, we empirically evaluate two weaknesses in Monero’s mixin sampling strategy. First, about 62% of transaction inputs with one or more mixins are vulnerable to “chain-reaction” analysis - that is, the real input can be deduced by elimination. Second, Monero mixins are sampled in such a way that they can be easily distinguished from the real coins by their age distribution; in short, the real input is usually the “newest” input. We estimate that this heuristic can be used to guess the real input with 80% accuracy over all transactions with 1 or more mixins. Next, we turn to the Monero ecosystem and study the importance of mining pools and the former anonymous marketplace AlphaBay on the transaction volume. We find that after removing mining pool activity, there remains a large amount of potentially privacy-sensitive transactions that are affected by these weaknesses. We propose and evaluate two countermeasures that can improve the privacy of future transactions.
Philippe Genestier, Sajida Zouarhi, Pascal Limeux, David Excoffier · 7 authors
In our digital world, access to personal data has become an item of concern, with challenging security and privacy aspects. Occurrences of hacking intentions and privacy violations make digital trust a major challenge. This is true in the eHealth area where management of patient health data must comply with many regulations, while remaining accessible to duly authorised health practitioners. Most will have heard about Blockchain because of its most known application - Bitcoin - in the payment area. However, Blockchain’s characteristics make it possible to fulfill the requirements of consent management, as illustrated in an implementation within a health domain use case.
This paper contributes a systematic account of transaction anonymization techniques that do not require trust in a single entity and support the existing cryptographic currency Bitcoin. It surveys and compares four known techniques, proposes tailored metrics to identify the use of each technique (but not necessarily its users), and presents longitudinal measurements indicating adoption trends and teething troubles. There is a tradeoff between the choice of users' preferred protection mechanisms and the risk that pertaining transactions can be singled out, which hurts privacy due to smaller anonymity sets unless a critical mass adopts the mechanism.
Towards the vision of building artificial intelligence systems that can assist with our everyday life, we introduce a proof of concept for a social media privacy "cyborg" which can locally and privately monitor a person's published content and offer advice or warnings when their privacy is at stake. The idea of a cyborg can be more general, as a separate local entity with its own computational resources, that can automatically perform several online tasks on our behalf. For this demonstration, we assume an attacker that can successfully infer user attributes, solely based on what the user has published (topic-based inference). We focus on Social Media privacy and specifically on the issue of exposing sensitive user-attributes, like location, or race, through published content. We built a privacy cyborg that can monitor a user's posted topics and automatically warn them in real time when a sensitive attribute is at risk of being exposed.
Aafaf Ouaddah, Anas Abou Elkalam, Abdellah Ait Ouahman
In this paper, we examine the possibility of using blockchain technology, mainly the second-generation of blockchain and smart contract, to create a new version of our decentralized pseudonymous & privacy preserving authorization management framework. Our framework relies on pseudonymous digital identity to ensure unlinkability, Smart contract to express access control policies and Blockchain technology to manage access control enforcement.
One of the fundamental applications for a practically useful system of money is remuneration. Information pertaining to the amount of compensation awarded to different individuals is often considered sensitive, commanding a certain degree of privacy. As Bitcoin and similarly designed cryptocurrencies evolve into a recognized medium of exchange for larger swaths of the world economy, an increasing number of people will earn income in the form of blockchain-based payments. The nature of these transactions is such that the minute details of an affected individuals compensation package and spending habits will be exposed to public scrutiny. In some cases this violates cultural norms which respect the confidentiality of salaries, yet in other cases it could be regarded as providing the benefits associated with greater transparency. In this work we analyse the Bitcoin blockchain record of periodic payments accruing to an individual address in exchange for goods or services rendered. For differing levels of available information we seek to determine the extent of insights that can be gleaned about the transacting counter-parties and the privacy implications this entails.
The latest Eurobarometer published in December 2016, reflecting the perceptions of the European citizens on privacy and security in telecommunications shows that, although people are not always informed on the privacy regulations or the implications of privacy breaches, they demand specific privacy protection. In particular, citizens want their data, their communications and the data that they give or outsource to online services to be well protected and not shared with unwanted parties. The demands of the public can be partly covered by the application of the privacy-by-design principle and the use of Privacy Enhancing Techniques (PETs) in commercial applications.
The privacy-by-design principle requires application designers to gather only the personal data that are essential to the correct operation of their applications. That is, applications following this principle should only ask the users to input those personal data that the specific application explicitly needs. Most applications in the market (and especially smartphone applications) clearly disregard this principle ---a look at the permissions they request is conclusive---: they collect contextual information too, even if it is not needed. The privacy policies of major service providers explain that all data may be used for commercial purposes.
Although major service providers collect more data than strictly necessary, the privacy-by-design principle demands that users be empowered with the decision about when to grant access to their data, when to modify them and when to delete them. While this is more or less being taken into account by service providers, sometimes the procedures to modify or delete personal data are not transparent enough or too cumbersome.
Privacy Enhancing Techniques (PET) are cryptographic and non-cryptographic tools that, when used appropriately, minimize the amount of personal data being handled by applications, and therefore help developers to more easily comply with regulations on personal data processing. Therefore, research on privacy enhancing techniques and on the practical deployment of the privacy-by-design principle is backed by the demands of the general population.
In this work we aim at demonstrating that, if appropriate techniques are used, privacy does not necessarily work against security and/or utility. We focus on three specific application cases described below:
- Group discounts are offered by vendors and public authorities to encourage a more sustainable (or profitable) way to access their services or use public resources. An example of this are high-occupancy vehicle (HOV) tolls in highways, which offer discounts for vehicles carrying more than a given number of passengers (2 or more, 3 or more, etc). There are several ways to ascertain the number of members of a group: employees at access points that count them, cameras that take photos and analyze them in toll booths, or registration procedures that require the names of all members of groups, among others.
We argue that automated mechanisms, such as cameras and registration procedures, take more information from the participants that is actually needed (thus violating the privacy-by-design principle), and that the only really necessary information is the size of the groups.
- Loyalty programs are marketing efforts implemented by vendors, especially retailers, that are aimed at establishing a lasting relationship with consumers. In a loyalty program, the vendor pursues two main goals: i) to encourage the consumer to make more purchases in the future (returning customer); ii) to allow the vendor to profile the consumer in view of conducting market research and segmentation (profiled customer). In order to lure consumers into a loyalty program, the vendor offers them rewards, typically loyalty points that consumers can later exchange for discounts, gifts or other benefits offered by the vendor.
Normally, enrollment to loyalty programs involves some kind of registration procedure, in which customers fill out a form with their personal information and are granted a loyalty card, be it a physical card (magnetic stripe or smartcard) or a smartphone application. Although loyalty programs have become widespread, they are experiencing a loss of active participants and they have been criticized by business experts and consumer associations. Criticism is mainly due to privacy issues, because it is not always clear whether the benefits offered by vendors in their loyalty programs are worth the loss of consumer privacy caused by profiling.
- Implicit authentication refers to a software system authenticating individuals based on the way they interact with their device, i.e. their behavior. In this context, the user's behavior can be determined by collecting a variety of features, such as keystroke patterns, browser history and configuration, IP addresses, location, visible antennas, etc. Implicit authentication can be viewed as a complement of the usual explicit authentication based on identifiers and credentials.
Note that a common trait in these three application cases is that users need to prove something about themselves or their context without revealing more than what is strictly necessary. We believe these cases can be used as an example for other applications in which the goal is similar.
The main contributions of this thesis are: 1. A group size accreditation method that preserves anonymity of the members of the groups. The anonymity provided by the scheme is congurable.
The method rests on two building blocks: (a) A new parameterized key management scheme for identity-based signatures that allows setting the anonymity level of users by providing them with multiple keys that are shared by many other users, but that are extracted from a unique identity.
(b) A novel IBDT signature scheme based on asymmetric bilinear pairings, that combines the properties of identity-based and threshold signature schemes. Signatures produced with this scheme reveal only the public keys of the group members, which are called identities, and the size of the signing group. The signature scheme is efficient, and the sizes of the signatures are constant.
2. A privacy-preserving loyalty program protocol suite, whereby vendors can issue and verify loyalty points, and customers can maintain their anonymity and con gure the level of generalization for their purchase receipts before submitting them for additional loyalty points. This allows vendors to still carry out client profiling in a privacy-aware way. This protocol suite combines the following techniques: (a) A new construction for anonymous (untransferable) tokens with controlled linkability based on partially blind signatures and zero-knowledge proofs. The construction allows issuing and verifying tokens, while the verifier cannot link tokens to a specific user or between concrete executions of the issuance and verification procedures, unless such a linkage is authorized by the user. Moreover, if a hardware based keystore is available, the tokens can be made untransferable, so that only users who originally received the tokens can submit them.
(b) Generalization techniques to select the level of anonymization of purchase receipts.
3. A mechanism to compute the distance between user profiles (expressed as feature sets of different data types) based on the size of the intersectionof the feature sets.
4. A privacy-preserving implicit authentication mechanism using the homomorphic properties of the Paillier cryptosystem, that protects the privacy of the sensitive data in the user's profile and ensures that the server does not learn anything about the user's behavior.
5. A second privacy-preserving implicit authentication with similar functionalities and higher speed compared to the previous one, based on the intersection of Bloom filters. While this mechanism provides slightly less protection than the previous one, its substantially better performance makes it ideal for implementation in existing authentication suites.
Mathieu Chanson, Alexander Bogner, Felix Wortmann, Elgar Fleisch
Giving people ownership of the data they produce becomes more and more important in times of ever-growing capabilities to collect and analyze data of individuals. In light of this challenge, we show how blockchain technology can enable privacy by presenting an odometer fraud prevention system. It records mileage and GPS data of cars and secures that on the blockchain, which strongly hinders odometer fraud. Our users own and control their data while at the same time data integrity is ensured. This facilitates the certification of that data. We discuss the advantages of this approach compared to current systems and also highlight limitations of our architecture and the use of blockchain technology.
Within the phenomenon known as the Internet of Things (IoT), an enormous growth is taking place. IoT systems exist in different ways, ranging from industrial applications to user focused systems. A specific subset of a user-focused IoT system is found as Smart Home environments. At Smart Homes, themultiple Smart Objects or Smart Devices are working together, frequently based on sensor input, to increase the comfort and user experience of the home inhabitant(s) and guest(s). Smart Objects can have automated tasks, home security enabling functions or efficiency improving functionality. Apart from great applications of Smart Home devices, threats from a cyber security perspective are present: cyber risks arise due to a variety of threats on such IoT systems. We show that in the development of new Smart Home products or systems, vendors fail to meet requirements for security and privacy are not met. Comparing the current state of the market, the four most used Smart Home ecosystems (Samsung Smartthings, Apple Homekit, Amazon Echo and IFTTT) are surveyed based on three key focus areas: 1. The regulatory compliance of the systems according to the upcoming General Data Protection Regulation (GDPR). 2. The commercial threats due to data profiling. 3. The risk of data leaks due to insufficient security. This analysis results in four key observations: 1. Security- and Privacy-By-Design is usually not in place due to the fact that the focus lies on launching a product as soon as possible, e.g. due to market competition; 2. Vendors process (meta)data on the vendors locations resulting in data profiling, which can compromise user privacy; 3. Smart Home ecosystems are not ready for the GDPR; 4. A trade off between privacy, security and utility usually results to the detriment of the first two and favors the latter. We propose a new design for a Smart Home ecosystem. In this design, the focus lies at the privacy of the end-user. We design a network for device-fitting encrypted communication between Smart Devices and User Devices and the Privacy Enforcing Arbiter (or Peter). Peter functions like a hub in the network, managing among others all traffic, user privileges and key distribution. With Peter, the centralized cloud party (vendor) for data storage and data analysis is replaced with a decentralized personal storage and computation entity at home. With our network design, we facilitate the use of IoT devices in home in a privacy-friendly way. Within the network, devices are authenticated using PhysicallyUnclonable Function technology and users are authenticated with a Zero Knowledge Proof. We analyze the privacy and security of our proposed network, based on a series of possible cyber attacks and the upcoming GDPR. Furthermore, we analyze the computational complexity and scalability of the network, based on market conform device power.
Internet voting has long been a topic both of public discussion and also of scientific research. While the introduction of Internet voting may bring many advantages, it is further important to ensure an adequate level of security of the systems and underlying schemes that are used for casting and tallying the votes in order to encourage faith and acceptance for this relatively new way of voting.
A number of cryptographic schemes have been proposed, that enable secure Internet voting. One of the most established and well-researched solutions is the Helios scheme, which is also implemented as an open-source system. Both its implementation and the scheme behind it has been extensively studied in the literature, and the Helios system has been used for numerous elections in practice, such as the IACR elections.
However, there are election settings for which Helios is currently not appropriate, either due to infrastructure demands, required functionality for the voters or assurance of the security requirements. These kinds of election settings could benefit from the advantages that secure Internet voting provides.
In this thesis we identify the election settings not currently supported by Helios, propose our extensions for each one of these settings and evaluate their security. Hence, this work describes four Internet voting schemes that are build upon Helios, with each scheme developed towards a specific setting.
The first scheme presented here enables elections within the so-called boardroom voting setting. This setting is characterized by its decentralization, whereby all the tasks within the election are distributively performed by the voters themselves, without the support of a centralized infrastructure. The election in the boardroom voting setting are further conducted in an ad-hoc manner, so that limited time is available for preparation beforehand. We propose an extension of Helios that distributes the tasks of the voting system components in Helios among the voters. For this, we use cryptographic primitives such as decentralized key exchange with short authentication strings, distributed secret sharing and distributed decryption and Byzantine agreement.
The second scheme extends Helios with proxy voting functionality. Proxy voting, as a newly emerged form of voting, enables the voter to delegate her voting right in the election to a trusted third-party, the so-called proxy, who is authorized to vote on the voter's behalf. This extension facilitates such delegation while assuring the security for delegating voters and for the proxies and preserves the security guarantees provided by Helios for the voters who vote directly (instead of delegating). For ensuring the security of our extension, we introduce the so-called delegation credentials that are assigned to the voters and are used to compute anonymized delegation tokens sent to the proxies to enable delegation. We further use cryptographic primitives such as proofs of knowledge and signatures of knowledge.
The third scheme combines the first two settings to extend Helios towards the proxy boardroom voting setting, namely, a setting in which the elections are performed in a decentralized way as in boardroom voting, yet the voters who cannot participate in the election themselves are allowed to delegate their voting right to a trusted proxy before the election. The security of our extension is assured with threshold secret sharing and Pedersen commitments.
The fourth scheme extends Helios by improving its security.
As such, it introduces participation privacy, meaning that the voting system does not reveal which voters have participated in the election, while supporting verification that only the eligible voters have cast their ballots in the election. The extension furthermore introduces receipt-freeness, ensuring that the voter cannot create a receipt that proves to a third party how she voted, thus preventing vote selling. To ensure the security of the extension, a new kind of entity is introduced, the posting trustee, and a new kind of ballot, the so-called dummy ballot that is indistinguishable from a normal ballot cast by the voter, but does not modify the election result. We furthermore use disjunctive zero-knowledge proofs and proofs of signature knowledge to prove, that a sender of a particular ballot knows the private signature key of an eligible voter, or that the ballot is a dummy ballot.
For each one of the extensions, the security model is provided, which describes the security requirements and the assumptions that are necessary for ensuring the security requirements (i.e. vote privacy or vote integrity), is provided. For the first three extensions, the security model is used as a base for the informal security evaluation, in which an informal argument is used to show, that the security requirements hold under the described assumptions. Conducting a formal security evaluation for these extensions is considered an important part of the future work, in which new formal definitions have to be developed.
For the fourth extension, we provide a formal security analysis that relies on the formal definitions for the security requirements of vote privacy, vote integrity and eligibility, available in the literature. We furthermore introduce new formal definitions for participation privacy, receipt-freeness and fairness, which we also use for the formal proofs of our extension.
Bitcoin has emerged as the leading cryptographic currency since its inception in 2009 and at the time of writing holds a market capitalization of $28.4 billion. This ever-increasing figure has attracted adopters seeking to advance their investments, often leaving purely technical aspects on the sidelines. As is the case with any innovative technology, misconceptions are plentiful and information is not always conclusive. The research effort presented in this paper consists of a quantitative study seeking to address the subject of user anonymity in the Bitcoin network by employing an online survey on one of the most prominent Bitcoin forums. This includes 50 eligible participants, whose motivation is derived through the application of temporal motivation theory. The survey seeks to form an understanding of user attitudes towards the aspect of anonymity by following a methodological approach for exploring common tendencies among the representatives and will serve as the underlying data set from which conclusions can be drawn. Furthermore, this paper will present a literary study of the actual state of anonymity in this peer-to-peer technology by reviewing current findings highlighted in the area, thus presenting a comprehensive view of anonymity in the Bitcoin network, which will contrast the user study.