Статті в журналах з теми "Broadcast primitives"

Collective communication performance is critical in a number of MPI applications. In this paper we focus on two widely used primitives, broadcast and reduce, and present experimental results obtained on a cluster of PC connected by InfiniBand. We integrated our algorithms in the MPICH library and we used MPICH implementation of broadcast and reduce primitives to compare the performance of our algorithms based on α-trees. Our tests show that the MPICH implementation can be improved.

Broadcast authentication in Controller Area Networks (CAN) is subject to real time constraints that are hard to satisfy by expensive public key primitives. For this purpose the authors study here the use of one-time signatures which can be built on the most computationally efficient one-way functions. The authors use an enhancement of the classical Merkle signature as well as the more recently proposed HORS signature scheme. Notably, these two proposals offer different trade-offs, and they can be efficiently paired with time synchronization to reduce the overhead caused by the re-initialization of the public keys, which would otherwise require expensive authentication trees. The authors do outline clear bounds on the performance of such a solution and provide experimental results on development boards equipped with Freescale S12X, a commonly used automotive grade micro-controller. The authors also benefit from the acceleration offered by the XGATE co-processor available on S12X derivatives which significantly increases the computational performances.

Broadcast is one of the fundamental network communication primitives. One node of a network, called the s ource, has a message that has to be learned by all other nodes. We consider broadcast in radio networks, modeled as simple undirected connected graphs with a distinguished source. Nodes communicate in synchronous rounds. In each round, a node can either transmit a message to all its neighbours, or stay silent and listen. At the receiving end, a node v hears a message from a neighbour w in a given round if v listens in this round and if w is its only neighbour that transmits in this round. If more than one neighbour of a node v transmits in a given round, we say that a c ollision occurs at v . We do not assume collision detection: in case of a collision, node v does not hear anything (except the background noise that it also hears when no neighbour transmits). We are interested in the feasibility of deterministic broadcast in radio networks. If nodes of the network do not have any labels, deterministic broadcast is impossible even in the four-cycle. On the other hand, if all nodes have distinct labels, then broadcast can be carried out, e.g., in a round-robin fashion, and hence O (log n )-bit labels are sufficient for this task in n -node networks. In fact, O (log Δ)-bit labels, where Δ is the maximum degree, are enough to broadcast successfully. Hence, it is natural to ask if very short labels are sufficient for broadcast. Our main result is a positive answer to this question. We show that every radio network can be labeled using 2 bits in such a way that broadcast can be accomplished by some universal deterministic algorithm that does not know the network topology nor any bound on its size. Moreover, at the expense of an extra bit in the labels, we can get the following additional strong property of our algorithm: there exists a common round in which all nodes know that broadcast has been completed. Finally, we show that 3-bit labels are also sufficient to solve both versions of broadcast in the case where it is not known a priori which node is the source.

The recent advent of cloud computing provides a flexible way to effectively share data among multiple users. Cloud computing and cryptographic primitives are changing the way of healthcare unprecedentedly by providing real-time data sharing cost-effectively. Sharing various data items from different users to multiple sets of legitimate subscribers in the cloud environment is a challenging issue. The online electronic healthcare system requires multiple data items to be shared by different users for various purposes. In the present scenario, COVID-19 data is sensitive and must be encrypted to ensure data privacy. Secure sharing of such information is crucial. The standard broadcast encryption system is inefficient for this purpose. Multichannel broadcast encryption is a mechanism that enables secure sharing of different messages to different set of users efficiently. We propose an efficient and secure data sharing method with shorter ciphertext in public key setting using asymmetric (Type-III) pairings. The Type-III setting is the most efficient form among all pairing types regarding operations required and security. The semantic security of this method is proven under decisional BDHE complexity assumption without random oracle model.

In this work we introduce the design and internal workings of the Iris decentralized messaging framework. Iris takes a midway approach between the two prevalent messaging middleware models: the centralized one represented by the AMQP family and the socket queuing one represented by ZeroMQ; by turning towards peer-to-peer overlays as the internal transport for message distribution and delivery. A novel concept is introduced, whereby a distributed service is composed not of individual application instances, but rather clusters of instances responsible for the same sub-service. Supporting this new model, a collection of higher level messaging patterns have been identified and successfully implemented: broadcast, request/reply, publish/subscribe and tunnel. This conceptual model and supporting primitives allow a much simpler way to specify, design and implement distributed, cloud based services. Furthermore, the proposed system achieves a significant switching speed, which - given its decentralized nature - can be scaled better than existing messaging frameworks, whilst incurring zero configuration costs.

In the Internet of Things (IoT) systems, it is often required to deliver a secure message to a group of devices. The public key broadcast encryption is an efficient primitive to handle IoT broadcasts, by allowing a user (or a device) to broadcast encrypted messages to a group of legitimate devices. This paper proposes an IoT-friendly subset representation called Combinatorial Subset Difference (CSD), which generalizes the existing subset difference (SD) method by allowing wildcards (*) in any position of the bitstring. Based on the CSD representation, we first propose an algorithm to construct the CSD subset, and a CSD-based public key broadcast encryption scheme. By providing the most general subset representation, the proposed CSD-based construction achieves a minimal header size among the existing broadcast encryption. The experimental result shows that our CSD saves the header size by 17% on average and more than 1000 times when assuming a specific IoT example of IP address with 20 wildcards and 2 20 total users, compared to the SD-based broadcast encryption. We prove the semantic security of CSD-based broadcast encryption under the standard l-BDHE assumption, and extend the construction to a chosen-ciphertext-attack (CCA)-secure version.

We studied the response of males to the singing of nearby male conspecifics in two species of the orthopteran genus Cyphoderris, primitive relatives of crickets and katydids. Lone male Cyphoderris buckelli stridulating in a large cage made a phonotactic approach to a nearby speaker broadcasting conspecific calling song. But in field experiments no phonotaxis to song broadcasts occurred; rather, a significant number of male C. buckelli increased their chirp duty cycle and pulse rate. There was no change in their carrier frequency. Calling male Cyphoderris monstrosa were exposed in the field to (i) playback of a synthetic calling song at a typical conspecific pulse rate, (ii) relayed broadcast of their own call, and (iii) low-frequency audio noise. Call duty cycle decreased significantly in response to the noise, while the pooled song models fell just short of significance. Singing C. buckelli were marked individually and their perches flagged over successive nights. We observed low site fidelity and extensive male displacement. Such behaviour is inconsistent with defense of topographically fixed singing territories and concurs with the absence of fighting in this species. Chirp duty cycle was increased significantly in C. buckelli in response to the singing of nearby conspecifics, but unlike in C. monstrosa, this change in duty cycle plays no role in overt aggression, though it may maintain a male's relative attractiveness to females.

Cyphoderris strepitans, is a primitive orthopteran which survives only in the mountains of Wyoming and Colorado (Morris and Gwynne 1978). The males rub their forewings together to produce a calling song. This stridulation is presumed to function, as in other acoustic Orthoptera, in attracting conspecific fema1es for mating and in maintaining a broadcast territory around each singer.

Broadcast authentication is a fundamental security primitive in wireless sensor networks (WSNs), which is a critical sensing component of IoT. Although symmetric-key-based μTESLA protocol has been proposed, some concerns about the difficulty of predicting the network lifecycle in advance and the security problems caused by an overlong long hash chain still remain. This paper presents a scalable broadcast authentication scheme named DH-μTESLA, which is an extension and improvement of μTESLA and Multilevel μTESLA, to achieve several vital properties, such as infinite lifecycle of hash chains, security authentication, scalability, and strong tolerance of message loss. The proposal consists of the t,n-threshold-based self-reinitializable hash chain scheme (SRHC-TD) and the d-left-counting-Bloom-filter-based authentication scheme (AdlCBF). In comparison to other broadcast authentication protocols, our proposal achieves more security properties such as fresh node’s participation and DoS resistance. Furthermore, the reinitializable hash chain constructed in SRHC-TD is proved to be secure and has less computation and communication overhead compared with typical solutions, and efficient storage is realized based on AdlCBF, which can also defend against DoS attacks.

In vehicular networks, efficient multi-hop message dissemination can be used for various purposes, such a informing the driver about the recent emergency event or propagating the local dynamic map of a predefined region. Dissemination of warning information up to a longer distance can reduce the accidents on the road. It provides a driver additional time to react to the situations adequately and assists in finding a safe route towards the destination. The adopted V2X standards, ETSI TS’s C-ITS and IEEE 1609/IEEE 802.11p, specify only primitive multi-hop message dissemination schemes. IEEE 1609.4 standard disseminates the broadcast messages using the method of flooding, which causes high redundancy, severe congestion, and long delay during multi-hop propagation. To address these problems, we propose an effective broadcast message dissemination method. It introduces a notion of source Lateral Crossing Line (LCL) algorithm, which elects a set of relay vehicles for each hop based on the vehicle locations in a way that reduces the redundant retransmission and congestion, consequently minimizing the delays. Our simulation results demonstrated that the proposed method can achieve about 15% reduction in delays and 2 times the enhancement in propagation distance compared with the previous methods.

Bag-of-Tasks applications are parallel applications composed of independent (i.e., embarrassingly parallel) tasks that do not communicate with each other, may depend upon one or more input files, and can be executed in any order. Each file may be input for more than one task. A common framework to execute BoT applications is the master-slave topology, in which the user machine is used to control the execution of tasks. In this scenario, a large number of concurrent tasks competing for resources (e.g., CPU and communication links) severely limits the scalability. In this paper we studied the scalability of BoT applications running on multi-node systems (e.g. clusters and grids) organized as master-slave platforms, considering two communications paradigms: multiplexed connections and efficient broadcast. We prove that the lowest bound possible on the isoefficiency function for master-slave platforms is achievable by those platforms that have an O(1) efficient broadcast primitive available. We also analyze the impact of output file contention in scalability, under different assumptions. Our study employs a set of simulation experiments that confirms and extends the theoretical results (e.g. by simulating TCP links).

Attribute-based authenticated key exchange (AB-AKE) is a useful primitive that allows a group of users to establish a shared secret key and at the same time enables fine-grained access control. A straightforward approach to design an AB-AKE protocol is to extend a key exchange protocol using an attribute-based authentication technique. However, insider security is a challenge security issue for AB-AKE in the multi-party setting and cannot be solved using the straightforward approach. In addtion, many existing key exchange protocols for the multi-party setting (e.g., the well-known Burmester-Desmedt protocol) require multiple broadcast rounds to complete the protocol. In this paper, we propose a novel one-round attribute-based key exchange (OAKE) protocol in the multi-party setting. We define the formal security models, including session key security, insider security and user privacy, for OAKE, and prove the security of the proposed protocol under some standard assumptions in the random oracle model.

The design of rational cryptographic protocols is a recently created research area at the intersection of cryptography and game theory. In this paper, we propose a new m-out-of-n rational secret sharing scheme requiring neither the involvement of the dealer (except during the initial share distribution) nor a trusted mediator. Our protocol leads to a Nash equilibrium surviving the iterated deletion of weakly dominated strategies for m ≥ 4. Our construction is information theoretically secure and it is immune against backward induction attacks. Contrary to Kol and Naor who used a specific cryptographic primitive in their TCC'08 paper (namely, meaningful/meaningless encryption), the immunity of our scheme is based on the use of bivariate polynomials and one-time pads. To the best of our knowledge, it is the first time that such polynomials have been used for rational secret sharing. Our scheme is efficient and does not require any physical assumptions such as envelopes or ballot boxes. As most of existing rational protocols, our construction requires simultaneous broadcast channels. However, our proposed scheme does not require any computational assumption and it provides information theoretical security.

We examine the role of self-maintenance (collective autocatalysis) in the evolution of computational biochemical networks. In primitive proto-cells (lacking separate genetic machinery) self-maintenance is a necessary condition for the direct reproduction and inheritance of what we here term Cellular Information Processing Networks (CIPNs). Indeed, partially reproduced or defective CIPNs may generally lead to malfunctioning or premature death of affected cells. We explore the interaction of this self-maintenance property with the evolution and adaptation of CIPNs capable of distinct information processing abilities. We present an evolutionary simulation platform capable of evolving artificial CIPNs from a bottom-up perspective. This system is an agent-based multi-level selectional Artificial Chemistry (AC) which employs a term rewriting system called the Molecular Classifier System (MCS.bl). The latter is derived from the Holland broadcast language formalism. Using this system, we successfully evolve an artificial CIPN to improve performance on a simple pre-specified information processing task whilst subject to the constraint of continuous self-maintenance. We also describe the evolution of self-maintaining, cross-talking and multi-tasking, CIPNs exhibiting a higher level of topological and functional complexity. This proof of concept aims at contributing to the understanding of the open-ended evolutionary growth of complexity in artificial systems.

Abstract Attribute-based proxy re-encryption (ABPRE), which combines the notions of proxy re-encryption (PRE) and attribute-based encryption (ABE), allows a semi-trusted proxy with re-encryption key to transform a ciphertext under a particular access policy into a ciphertext under another access policy, without revealing any information about the underlying plaintext. This primitive is very useful in applications where encrypted data need to be stored in untrusted environments, such as cloud storage. In many practical applications, and in order to address scenarios where users misbehave or the re-encryption keys are compromised, an efficient revocation mechanism is necessary for ABPRE. Previously, revocation mechanism was considered in the settings of identity-based encryption (IBE), ABE, predicate encryption (PE), and broadcast PRE, but not ABPRE, which is what we set to do in this paper. We first formalize the concept of revocable ABPRE and its security model. Then, we propose a lattice-based instantiation of revocable ABPRE. Our scheme not only supports an efficient revocation mechanism but also supports polynomial-depth policy circuits and has short private keys, where the size of the keys is dependent only on the depth of the supported policy circuits. In addition, we prove that our scheme is selectively chosen-plaintext attack (CPA) secure in the standard model, based on the learning with errors assumption.

Noradrenaline is released throughout the forebrain from locus coeruleus (LC) projections in close temporal proximity to emotional and goal-directed events. To examine interactive influences of these processes on LC neuronal activity, we used a task where Pavlovian and operant processes vary and can be easily identified. We recorded 69 single LC neurons from two monkeys performing a task where cues indicate the progression through schedules of one, two, or three operant trials. Pavlovian responses and phasic LC activations occur following the appearance of conditioned visual cues (54/69 neurons), especially those at the beginning of new schedules, whether the current trial will be rewarded (single trial schedule) or not (2 or 3 trial schedules), and after visual imperative signals eliciting the operant response (64/69 neurons), whether the current trial will be rewarded or not. The modulation of LC responses seems to be relatively independent of attention or motivation, because the responses do not covary with operant performance in the task. The magnitude of LC responses across the schedules varied in close relation to the intensity of Pavlovian behavior but these responses were also modulated by operant processes. Our conclusion is that LC activation occurs when task-relevant stimuli evoke a conditioned instinctive (Pavlovian) response, with the strength of the activation also being modulated by goal-directed processes. Thus locus coeruleus neurons broadcast information about stimulus-elicited primitive and goal-directed behaviors to forebrain structures important for executive functions and emotions.

Cryptographic primitive of timed-release encryption (TRE) enables the sender to encrypt a message which only allows the designated receiver to decrypt after a designated time. Combined with other encryption technologies, TRE technology is applied to a variety of scenarios, including regularly posting on the social network and online sealed bidding. Nowadays, in order to control the decryption time while maintaining anonymity of user identities, most TRE solutions adopt a noninteractive time server mode to periodically broadcast time trapdoors, but because these time trapdoors are generated with fixed time server’s private key, many “ciphertexts” related to the time server’s private key that can be cryptanalyzed are generated, which poses a big challenge to the confidentiality of the time server’s private key. To work this out, we propose a concrete scheme and a generic scheme of security-enhanced TRE (SETRE) in the random oracle model. In our SETRE schemes, we use fixed and variable random numbers together as the time server’s private key to generate the time trapdoors. We formalize the definition of SETRE and give a provably secure concrete construction of SETRE. According to our experiment, the concrete scheme we proposed reduces the computational cost by about 10.8% compared to the most efficient solution in the random oracle model but only increases the almost negligible storage space. Meanwhile, it realizes one-time pad for the time trapdoor. To a large extent, this increases the security of the time server’s private key. Therefore, our work enhances the security and efficiency of the TRE.

Sagebrush crickets (Cyphoderris strepitans) are primitive acoustic insects which occur only in mountainous areas of Wyoming and Colorado (Morris and Gwynne 1978). In Grand Teton National Park, adults become sexually active in early May and matings subsequently occur over a 3 - 6 week period. Each night of the breeding season, males emerge from the soil litter shortly after sunset, climb into the sagebrush and begin to sing, presumably to attract sexually receptive females. Copulation is initiated when a receptive female climbs onto the dorsum of a male, at which time he attempts to transfer a spermatophore (Dodson et al. 1983, Sakaluk et al. 1987, Morris et al. 1989). During the time that the female is mounted on the male, she feeds on the male's metathoracic wings and ingests any hemolymph oozing from the wounds she inflicts. To deter the female from dismounting before the spermatophore has been transferred, males are equipped with an abdominal pinching organ which functions to secure the female during copulation (Morris 1979, Dodson et al. 1983). Once the spermatophore has disengagement. The bulk of the spermatophore remains attached outside the female's body, who invariably consumes it several hours after mating (present study). A previous field study involving the mark-recapture of a large number of males showed that once a male had mated, his probability of obtaining additional copulations was significantly reduced (Morris et al. 1986). One explanation for this result is that non-virgin males, having lost a substantial portion of available energy reserves at mating, may be unable to sustain calling at pre-mating levels. In support of this hypothesis, electronic assays of male signaling behavior (see Kidder and Sakaluk, in press) have shown that virgin male C. strepitans call for significantly longer durations than recently mated males (Sakaluk et al.1987, Sakaluk and Snedden 1990). Although virgin males call more and have significantly higher mating success than non-virgins, this does not necessarily prove that calling duration and mating success are causally related. In the past, we have experienced two difficulties in establishing a causal basis to this correlation: 1) matings are rarely observed in the field, and we have of necessity relied on wing wounding as an indicator of male mating success (Morris et al. 1989) and 2) we have been unable to demonstrate phonotaxis of females to conspecific song as broadcast either through speakers placed in the field (Sakaluk and Snedden, unpubl. data) or in the laboratory (Morris et al. 1989). To at least partially circumvent these difficulties, we employed time-lapse video photography of mating interactions staged at the UW-NPS Research Station during the 1989 breeding season. The objective of these studies was to determine how mating status, calling time and body size contribute to male mating success, either through their effect on male competitive ability and/or their effect on male attractiveness to females.

Distributed surveillance systems have the ability to detect, track, and snapshot objects moving around in a certain space. The systems generate video data from multiple personal devices or street cameras. Intelligent video-analysis models are needed to learn dynamic representation of the objects for detection and tracking. Can we exploit the structural and dynamic information, without storing the spatiotemporal video data at a central server that leads to a violation of user privacy? In this work, we introduce Federated Dynamic Graph Neural Network (Feddy), a distributed and secured framework to learn the object representations from graph sequences: (1) It aggregates structural information from nearby objects in the current graph as well as dynamic information from those in the previous graph. It uses a self-supervised loss of predicting the trajectories of objects. (2) It is trained in a federated learning manner. The centrally located server sends the model to user devices. Local models on the respective user devices learn and periodically send their learning to the central server without ever exposing the user’s data to server. (3) Studies showed that the aggregated parameters could be inspected though decrypted when broadcast to clients for model synchronizing, after the server performed a weighted average. We design an appropriate aggregation mechanism of secure aggregation primitives that can protect the security and privacy in federated learning with scalability. Experiments on four video camera datasets as well as simulation demonstrate that Feddy achieves great effectiveness and security.

In vehicular ad hoc networks (VANETs), for a large number of applications, the destination of relevant information such as alerts, is the whole set of vehicles located inside a given area. Therefore dissemination with efficient broadcast is an essential communication primitive. One of the families of broadcast protocols suitable for such networks, is the family of delay-based broadcast protocols, where farthest receivers retransmit first and where transmissions also act as implicit acknowledgements. For lossless networks, such protocols may approach the optimum efficiency. However with realistic loss models of VANET wireless communication, their performance is noticeably degraded. This is because packet losses have a double effect: directly on the amount of successfully received packets and indirectly with implicit acknowledgement misses. In this article, in order to combat the effects of packet losses, we combine delay-based broadcast with network coding, through a new protocol: Delay-based Opportunistic Network Coding protocol (DONC). By design, DONC aims at cancelling the twofold effects of packet and implicit acknowledgement losses. We describe the details of the DONC protocol, and we study its behavior, with realistic models and simulations. Results illustrate the excellent performance of the protocol.

AbstractTensorFlow (TF) is usually combined with the Horovod (HVD) workload distribution package to obtain a parallel tool to train deep neural network on clusters of computers. HVD in turn utilizes a blocking Allreduce primitive to share information among processes, combined with a communication thread to overlap communication with computation. In this work, we perform a thorough experimental analysis to expose (1) the importance of selecting the best algorithm in MPI libraries to realize the Allreduce operation; and (2) the performance acceleration that can be attained when replacing a blocking Allreduce with its non-blocking counterpart (while maintaining the blocking behaviour via the appropriate synchronization mechanism). Furthermore, (3) we explore the benefits of applying pipelining to the communication exchange, demonstrating that these improvements carry over to distributed training via TF+HVD. Finally, (4) we show that pipelining can also boost performance for applications that make heavy use of other collectives, such as Broadcast and Reduce-Scatter.

In Nigeria, cultural contents have continued to be explored in relation to their typologies, taxonomies and social value. Some folklore materials are disappearing due to modernisation and globalisation, leaving marginal communities to turn to alien models, some of which are not effective or accessible. The desire for a community-based model is weak as it is considered primitive and inferior to contemporary existence. Folklorists are too few with too little research wherewithal to carry out an extensive and broad-based study on oral art forms and their continued relevance to society. An ironic hybrid and interdisciplinary connectivity exists between folklore and multimedia as cultural materials adopt modern technologies, which an in-depth study could bring to light. This article, using the contextual perspective of analysis, examines ways in which folklore materials could continue to be explored even in their dynamic new multimedia “homes” such as music, photography, moving images, audio, computer, and broadcast media, thus creating new narrative and performance spaces other than the oral and the literary, and a new interface between folklore and modern technology life. The article proposes the undertaking of enhanced research into the hidden dimensions of folklore and the re-fashioning of cultural thought, science and technology, in line with cultural and global trends towards enhanced knowledge and development.

Cosplay is considered as a modern mass practice of copying and public demonstration of the costume, image and behavior of famous heroes in the mass culture: heroes of movies, cartoons, comics, video games within the framework of festivals, processions, activities of clubs of the corresponding subject. The empirical material for the study was observations, publications in specialized mass media, recordings of Russian and foreign electronic broadcasts of cosplay events, interviews with Russian cosplayers. The article provides a cultural and historical analysis of cosplay, on the basis of which it is concluded that the archaic cultural forms of totemic primitive holidays, medieval carnival, and the first forms of theater are reproduced in cosplay. Traditional cultural forms in cosplay are endowed with new cultural meanings, among which are the game principal development in culture, the implementation of special mechanisms of young people socialization through individual and collective forms of identification and imitation of famous characters, creative development of screen culture characters. In cosplay, there is a partial revitalization of archaic cultural forms, such as zoo-mystery, carnival, the first forms of theater. The conclusion is made about the role of cosplay in the development of the visual language of modernity, «de-virtualization» of the mass culture images and the development of the «instinct of theatricality» in a modern person. Cosplay in Russia demonstrates a wider thematic repertoire than cosplay in the USA and Japan: it includes not only images of American films, video games, comics, Japanese manga and anime, but also images of Soviet animation, which paradoxically are capable of direct competition with modern products of mass culture and art.

Purpose Until now, a lot of research has been done and applied to provide security and original data from one user to another, such as third-party auditing and several schemes for securing the data, such as the generation of the key with the help of encryption algorithms like Rivest–Shamir–Adleman and others. Here are some of the related works that have been done previously. Remote damage control resuscitation (RDCR) scheme by Yan et al. (2017) is proposed based on the minimum bandwidth. By enabling the third party to perform the verification of public integrity. Although it supports the repair management for the corrupt data and tries to recover the original data, in practicality it fails to do so, and thus it takes more computation and communication cost than our proposed system. In a paper by Chen et al. (2015), using broadcast encryption, an idea for cloud storage data sharing has been developed. This technique aims to accomplish both broadcast data and dynamic sharing, allowing users to join and leave a group without affecting the electronic press kit (EPK). In this case, the theoretical notion was true and new, but the system’s practicality and efficiency were not acceptable, and the system’s security was also jeopardised because it proposed adding a member without altering any keys. In this research, an identity-based encryption strategy for data sharing was investigated, as well as key management and metadata techniques to improve model security (Jiang and Guo, 2017). The forward and reverse ciphertext security is supplied here. However, it is more difficult to put into practice, and one of its limitations is that it can only be used for very large amounts of cloud storage. Here, it extends support for dynamic data modification by batch auditing. The important feature of the secure and efficient privacy preserving provable data possession in cloud storage scheme was to support every important feature which includes data dynamics, privacy preservation, batch auditing and blockers verification for an untrusted and an outsourced storage model (Pathare and Chouragadec, 2017). A homomorphic signature mechanism was devised to prevent the usage of the public key certificate, which was based on the new id. This signature system was shown to be resistant to the id attack on the random oracle model and the assault of forged message (Nayak and Tripathy, 2018; Lin et al., 2017). When storing data in a public cloud, one issue is that the data owner must give an enormous number of keys to the users in order for them to access the files. At this place, the knowledge assisted software engineering (KASE) plan was publicly unveiled for the first time. While sharing a huge number of documents, the data owner simply has to supply the specific key to the user, and the user only needs to provide the single trapdoor. Although the concept is innovative, the KASE technique does not apply to the increasingly common manufactured cloud. Cui et al. (2016) claim that as the amount of data grows, distribution management system (DMS) will be unable to handle it. As a result, various proven data possession (PDP) schemes have been developed, and practically all data lacks security. So, here in these certificates, PDP was introduced, which was based on bilinear pairing. Because of its feature of being robust as well as efficient, this is mostly applicable in DMS. The main purpose of this research is to design and implement a secure cloud infrastructure for sharing group data. This research provides an efficient and secure protocol for multiple user data in the cloud, allowing many users to easily share data. Design/methodology/approach The methodology and contribution of this paper is given as follows. The major goal of this study is to design and implement a secure cloud infrastructure for sharing group data. This study provides an efficient and secure protocol for multiple user data in cloud, allowing several users to share data without difficulty. The primary purpose of this research is to design and implement a secure cloud infrastructure for sharing group data. This research develops an efficient and secure protocol for multiple user data in the cloud, allowing numerous users to exchange data without difficulty. Selection scheme design (SSD) comprises two algorithms; first algorithm is designed for limited users and algorithm 2 is redesigned for the multiple users. Further, the authors design SSD-security protocol which comprises a three-phase model, namely, Phase 1, Phase 2 and Phase 3. Phase 1 generates the parameters and distributes the private key, the second phase generates the general key for all the users that are available and third phase is designed to prevent the dishonest user to entertain in data sharing. Findings Data sharing in cloud computing provides unlimited computational resources and storage to enterprise and individuals; moreover, cloud computing leads to several privacy and security concerns such as fault tolerance, reliability, confidentiality and data integrity. Furthermore, the key consensus mechanism is fundamental cryptographic primitive for secure communication; moreover, motivated by this phenomenon, the authors developed SSDmechanismwhich embraces the multiple users in the data-sharing model. Originality/value Files shared in the cloud should be encrypted for security purpose; later these files are decrypted for the users to access the file. Furthermore, the key consensus process is a crucial cryptographic primitive for secure communication; additionally, the authors devised the SSD mechanism, which incorporates numerous users in the data-sharing model, as a result of this phenomena. For evaluation of the SSD method, the authors have considered the ideal environment of the system, that is, the authors have used java as a programming language and eclipse as the integrated drive electronics tool for the proposed model evaluation. Hardware configuration of the model is such that it is packed with 4 GB RAM and i7 processor, the authors have used the PBC library for the pairing operations (PBC Library, 2022). Furthermore, in the following section of this paper, the number of users is varied to compare with the existing methodology RDIC (Li et al., 2020). For the purposes of the SSD-security protocol, a prime number is chosen as the number of users in this work.

I called your producer on the way here in the car because I was very excited. I found out … I did one of those genetic testing things and I found out that I'm 63 percent Irish … I had no idea. I had no idea! I thought I was Scottish and Welsh. It turns out my parents are just full of shit, I guess. But now I’m Irish and it just makes so much sense! I'm a really good drinker. I love St. Patrick's Day. Potatoes are delicious. I'm looking forward to meeting all my cousins … [to Conan O’Brien] You and I are probably related! … Now I get to say things like, “It’s in me genes! I love that Conan O’Brien; he’s such a nice fella.” You’re kinda like a giant leprechaun. (Reese Witherspoon, Tuesday 21 March 2017)IntroductionAs an Irishman and a football fan, I watched the unfolding 2016 UEFA European Championship in France (hereafter ‘Euro 2016’) with a mixture of trepidation and delight. Although the Republic of Ireland team was eventually knocked out of the competition in defeat to the host nation, the players performed extremely well – most notably in defeating Italy 1:0. It is not the on-field performance of the Irish team that interests me in this short article, however, but rather how Irish fans travelling to the competition were depicted in the surrounding international news coverage. In particular, I focus on the centrality of fan footage – shot on smart phones and uploaded to YouTube (in most cases by fans themselves) – in this news coverage. In doing so, I reflect on how sports fans contribute to wider understandings of nationness in the global imagination and how their behaviour is often interpreted (as in the case here) through long-established tropes about people and places. The Media ManifoldTo “depict” something is to represent it in words and pictures. As the contemporary world is largely shaped by and dependent on mass media – and different forms of media have merged (or “converged”) through digital media platforms – mediated forms of depiction have become increasingly important in our lives. On one hand, the constant connectivity made possible in the digital age has made the representation of people and places less controllable, insofar as the information and knowledge about our world circulating through media devices are partly created by ordinary people. On the other hand, traditional broadcast media arguably remain the dominant narrators of people and places worldwide, and their stories, Gerbner reminds us, are largely formula-driven and dramatically charged, and work to “retribalize” modern society. However, a more important point, I suggest, is that so-called new and old media can no longer be thought of as separate and discrete; rather, our attention should focus on the complex interrelations made possible by deep mediatisation (Couldry and Hepp).As an example, consider that the Youtube video of Reese Witherspoon’s recent appearance on the Conan O’Brien chat show – from which the passage at the start of this article is taken – had already been viewed 54,669 times when I first viewed it, a mere 16 hours after it was originally posted. At that point, the televised interview had already been reported on in a variety of international digital news outlets, including rte.ie, independent.ie., nydailynews.com, msn.com, huffingtonpost.com, cote-ivoire.com – and myriad entertainment news sites. In other words, this short interview was consumed synchronously and asynchronously, over a number of different media platforms; it was viewed and reviewed, and critiqued and commented upon, and in turn found itself the subject of news commentary, which fed the ongoing cycle. And yet, it is important to also note that a multiplicity of media interactions does not automatically give rise to oppositional discourse and ideological contestation, as is sometimes assumed. In fact, how ostensibly ‘different’ kinds of media can work to produce a broadly shared construction of a people and place is particularly relevant here. Just as Reese Witherspoon’s interview on the Conan O’Brien show perpetuates a highly stereotypical version of Irishness across a number of platforms, news coverage of Irish fans at Euro 2016 largely conformed to established tropes about Irish people, but this was also fed – to some extent – by Irish fans themselves.Irish Identity, Sport, and the Global ImaginationThere is insufficient space here to describe in any detail the evolving representation of Irish identity, about which a vast literature has developed (nationally and internationally) over the past several decades. As with other varieties of nationness, Irishness has been constructed across a variety of cultural forms, including advertising, art, film, novels, travel brochures, plays and documentaries. Importantly, Irishness has also to a great extent been constructed outside of Ireland (Arrowsmith; Negra).As is well known, the Irish were historically constructed by their colonial masters as a small uncivilised race – as primitive wayward children, prone to “sentimentality, ineffectuality, nervous excitability and unworldliness” (Fanning 33). When pondering the “Celtic nature,” the renowned English poet and cultural critic Mathew Arnold concluded that “sentimental” was the best single term to use (100). This perception pervaded internationally, with early depictions of Irish-Americans in US cinema centring on varieties of negative excess, such as lawlessness, drunkenness and violence (Rains). Against this prevailing image of negative excess, the intellectuals and artists associated with what became known as the Celtic Revival began a conscious effort to “rebrand” Ireland from the nineteenth century onwards, reversing the negatives of the colonial project and celebrating Irish tradition, language and culture (Fanning).At first, only distinctly Irish sports associated with the amateur Gaelic Athletic Association (GAA) were co-opted in this very particular nation-building project. Since then, however, sport more generally has acted as a site for the negotiation of a variety of overlapping Irish identities. Cronin, for example, describes how the GAA successfully repackaged itself in the 1990s to reflect the confidence of Celtic Tiger Irishness while also remaining rooted in the counties and parishes across Ireland. Studies of Irish football and rugby have similarly examined how these sports have functioned as representatives of changed or evolving Irish identities (Arrowsmith; Free). And yet, throughout Ireland’s changing economic fortunes – from boom to bust, to the gradual renewal of late – a touristic image of Irishness has remained hegemonic in the global imagination. In popular culture, and especially American popular culture, Ireland is often depicted as a kind of pre-industrial theme park – a place where the effects of modernity are felt less, or are erased altogether (Negra). The Irish are known for their charm and sociability; in Clancy’s words, they are seen internationally as “simple, clever and friendly folk” (98). We can identify a number of representational tropes within this dominant image, but two in particular are apposite here: ‘smallness’ and ‘happy-go-luckiness’.Sporting NewsBefore we consider Euro 2016, it is worth briefly considering how the news industry approaches such events. “News”, Dahlgren reminds us, is not so much “information” as it is a specific kind of cultural discourse. News, in other words, is a particular kind of discursive composition that constructs and narrates stories in particular ways. Approaching sports coverage from this vantage point, Poulton and Roderick (xviii) suggest that “sport offers everything a good story should have: heroes and villains, triumph and disaster, achievement and despair, tension and drama.” Similarly, Jason Tuck observes that the media have long had a tendency to employ the “vocabulary of war” to “hype up sporting events,” a discursive tactic which, he argues, links “the two areas of life where the nation is a primary signifier” (190-191).In short, sport is abundant in news values, and media professionals strive to produce coverage that is attractive, interesting and exciting for audiences. Stead (340) suggests that there are three key characteristics governing the production of “media sports packages”: spectacularisation, dramatisation, and personalisation. These production characteristics ensure that sports coverage is exciting and interesting for viewers, but that it also in some respects conforms to their expectations. “This ‘emergent’ quality of sport in the media helps meet the perpetual audience need for something new and different alongside what is familiar and known” (Rowe 32). The disproportionate attention to Irish fans at Euro 2016 was perhaps new, but the overall depiction of the Irish was rather old, I would argue. The news discourse surrounding Euro 2016 worked to suggest, in the Irish case at least, that the nation was embodied not only in its on-field athletic representatives but more so, perhaps, in its travelling fans.Euro 2016In June 2016 the Euros kicked off in France, with the home team beating Romania 2-1. Despite widespread fears of potential terrorist attacks and disruption, the event passed successfully, with Portugal eventually lifting the Henri Delaunay Trophy. As the competition progressed, the behaviour of Irish fans quickly became a central news story, fuelled in large part by smart phone footage uploaded to the internet by Irish fans themselves. Amongst the many videos uploaded to the internet, several became the focus of news reports, especially those in which the goodwill and childlike playfulness of the Irish were on show. In one such video, Irish fans are seen singing lullabies to a baby on a Bordeaux train. In another video, Irish fans appear to help a French couple change a flat tire. In yet another video, Irish fans sing cheerfully as they clean up beer cans and bottles. (It is noteworthy that as of July 2017, some of these videos have been viewed several million times.)News providers quickly turned their attention to Irish fans, sometimes using these to draw stark contrasts with the behaviour of other fans, notably English and Russian fans. Buzzfeed, followed by ESPN, followed by Sky News, Le Monde, Fox News, the Washington Post and numerous other providers celebrated the exploits of Irish fans, with some such as Sky News and Aljazeera going so far as to produce video montages of the most “memorable moments” involving “the boys in green.” In an article titled ‘Irish fans win admirers at Euro 2016,’ Fox News reported that “social media is full of examples of Irish kindness” and that “that Irish wit has been a fixture at the tournament.” Aljazeera’s AJ+ news channel produced a video montage titled ‘Are Irish fans the champions of Euro 2016?’ which included spliced footage from some of the aforementioned videos. The Daily Mirror (UK edition) praised their “fun loving approach to watching football.” Similarly, a headline for NPR declared, “And as if they could not be adorable enough, in a quiet moment, Irish fans sang on a French train to help lull a baby to sleep.” It is important to note that viewer comments under many of these articles and videos were also generally effusive in their praise. For example, under the video ‘Irish Fans help French couple change flat tire,’ one viewer (Amsterdam 410) commented, ‘Irish people nicest people in world by far. they always happy just amazing people.’ Another (Juan Ardilla) commented, ‘Irish fans restored my faith in humanity.’As the final stages of the tournament approached, the Mayor of Paris announced that she was awarding the Medal of the City of Paris to Irish fans for their sporting goodwill. Back home in Ireland, the behaviour of Irish fans in France was also celebrated, with President Michael D. Higgins commenting that “Ireland could not wish for better ambassadors abroad.” In all of this news coverage, the humble kindness, helpfulness and friendliness of the Irish are depicted as native qualities and crystallise as a kind of ideal national character. Though laudatory, the tropes of smallness and happy-go-luckiness are again evident here, as is the recurrent depiction of Irishness as an ‘innocent identity’ (Negra). The “boys” in green are spirited in a non-threatening way, as children generally are. Notably, Stephan Reich, journalist with German sports magazine 11Freunde wrote: “the qualification of the Irish is a godsend. The Boys in Green can celebrate like no other nation, always peaceful, always sympathetic and emphatic, with an infectious, childlike joy.” Irishness as Antidote? The centrality of the Irish fan footage in the international news coverage of Euro 2016 is significant, I suggest, but interpreting its meaning is not a simple or straightforward task. Fans (like everyone) make choices about how to present themselves, and these choices are partly conscious and partly unconscious, partly spontaneous and partly conditioned. Pope (2008), for example, draws on Emile Durkheim to explain the behaviour of sports fans sociologically. “Sporting events,” Pope tells us, “exemplify the conditions of religious ritual: high rates of group interaction, focus on sacred symbols, and collective ritual behaviour symbolising group membership and strengthening shared beliefs, values, aspirations and emotions” (Pope 85). Pope reminds us, in other words, that what fans do and say, and wear and sing – in short, how they perform – is partly spontaneous and situated, and partly governed by a long-established fandom pedagogy that implies familiarity with a whole range of international football fan styles and embodied performances (Rowe). To this, we must add that fans of a national sports team generally uphold shared understandings of what constitutes desirable and appropriate patriotic behaviour. Finally, in the case reported here, we must also consider that the behaviour of Irish fans was also partly shaped by their awareness of participating in the developing media sport spectacle and, indeed, of their own position as ‘suppliers’ of news content. In effect, Irish fans at Euro 2016 occupied an interesting hybrid position between passive consumption and active production – ‘produser’ fans, as it were.On one hand, therefore, we can consider fan footage as evidence of spontaneous displays of affective unity, captured by fellow participants. The realism or ‘authenticity’ of these supposedly natural and unscripted performances is conveyed by the grainy images, and amateur, shaky camerawork, which ironically work to create an impression of unmediated reality (see Goldman and Papson). On the other hand, Mike Cronin considers them contrived, staged, and knowingly performative, and suggestive of “hyper-aware” Irish fans playing up to the camera.However, regardless of how we might explain or interpret these fan performances, it is the fact that they play a role in making Irishness public that most interests me here. For my purposes, the most important consideration is how the patriotic performances of Irish fans both fed and harmonized with the developing news coverage; the resulting depiction of the Irish was partly an outcome of journalistic conventions and partly a consequence of the self-essentialising performances of Irish fans. In a sense, these fan-centred videos were ready-made or ‘packaged’ for an international news audience: they are short, dramatic and entertaining, and their ideological content is in keeping with established tropes about Irishness. As a consequence, the media-sport discourse surrounding Euro 2016 – itself a mixture of international news values and home-grown essentialism – valorised a largely touristic understanding of Irishness, albeit one that many Irish people wilfully celebrate.Why such a construction of Irishness is internationally appealing is unclear, but it is certainly not new. John Fanning (26) cites a number of writers in highlighting that Ireland has long nurtured a romantic self-image that presents the country as a kind of balm for the complexities of the modern world. For example, he cites New York Times columnist Thomas Friedman, who observed in 2001 that “people all over the world are looking to Ireland for its reservoir of spirituality hoping to siphon off what they can feed to their souls which have become hungry for something other than consumption and computers.” Similarly, Diane Negra writes that “virtually every form of popular culture has in one way or another, presented Irishness as a moral antidote to contemporary ills ranging from globalisation to post-modern alienation, from crises over the meaning and practice of family values to environmental destruction” (3). Earlier, I described the Arnoldian image of the Irish as a race governed by ‘negative excess’. Arguably, in a time of profound ideological division and resurgent cultural nationalism – a time of polarisation and populism, of Trumpism and Euroscepticism – this ‘excess’ has once again been positively recoded, and now it is the ‘sentimental excess’ of the Irish that is imagined as a salve for the cultural schisms of our time.ConclusionMuch has been made of new media powers to contest official discourses. Sports fans, too, are now considered much less ‘controllable’ on account of their ability to disrupt official messages online (as well as offline). The case of Irish fans at Euro 2016, however, offers a reminder that we must avoid routine assumptions that the “uses” made of “new” and “old” media are necessarily divergent (Rowe, Ruddock and Hutchins). My interest here was less in what any single news item or fan-produced video tells us, but rather in the aggregate construction of Irishness that emerges in the media-sport discourse surrounding this event. Relatedly, in writing about the London Olympics, Wardle observed that most of what appeared on social media concerning the Games did not depart significantly from the celebratory tone of mainstream news media organisations. “In fact the absence of any story that threatened the hegemonic vision of the Games as nation-builder, shows that while social media provided an additional and new form of newsgathering, it had to fit within the traditional news structures, routines and agenda” (Wardle 12).Obviously, it is important to acknowledge the contestability of all media texts, including the news items and fan footage mentioned here, and to recognise that such texts are open to multiple interpretations based on diverse reading positions. And yet, here I have suggested that there is something of a ‘preferred’ reading in the depiction of Irish fans at Euro 2016. The news coverage, and the footage on which it draws, are important because of what they collectively suggest about Irish national identity: here we witness a shift from identity performance to identity writ large, and one means of analysing their international (and intertextual significance), I have suggested, is to view them through the prism of established tropes about Irishness.Travelling sports fans – for better or worse – are ‘carriers’ of places and cultures, and they remind us that “there is also a cultural economy of sport, where information, images, ideas and rhetorics are exchanged, where symbolic value is added, where metaphorical (and sometimes literal, in the case of publicly listed sports clubs) stocks rise and fall” (Rowe 24). There is no question, to borrow Rowe’s term, that Ireland’s ‘stocks’ rose considerably on account of Euro 2016. In news terms, Irish fans provided entertainment value; they were the ‘human interest’ story of the tournament; they were the ‘feel-good’ factor of the event – and importantly, they were the suppliers of much of this content (albeit unofficially). Ultimately, I suggest that we think of the overall depiction of the Irish at Euro 2016 as a co-construction of international news media practices and the self-presentational practices of Irish fans themselves. The result was not simply a depiction of idealised fandom, but more importantly, an idealisation of a people and a place, in which the plucky little people on tour became the global standard bearers of Irish identity.ReferencesArnold, Mathew. Celtic Literature. Carolina: Lulu Press, 2013.Arrowsmith, Aidan. “Plastic Paddies vs. Master Racers: ‘Soccer’ and Irish Identity.” International Journal of Cultural Studies 7.4 (2004). 25 Mar. 2017 <http://journals.sagepub.com/doi/pdf/10.1177/1367877904047864>.Boards and Networked Digital Media Sport Communities.” Convergence 16.3 (2010). 25 Mar. 2017 <http://journals.sagepub.com/doi/abs/10.1177/1354856510367622>.Clancy, Michael. Brand New Ireland: Tourism, Development and National Identity in the Irish Republic. Surrey and Vermont: Ashgate, 2009.Couldry, Nick, and Andreas Hepp. The Mediated Construction of Reality. Cambridge: Polity Press, 2016.Cronin, Michael. “Is It for the Glamour? Masculinity, Nationhood and Amateurism in Contemporary Projections of the Gaelic Athletic Association.” Irish Postmodernisms and Popular Culture. Eds. Wanda Balzano, Anne Mulhall, and Moynagh Sullivan. New York: Palgrave Macmillan, 2007. 39–51.Cronin, Mike. “Serenading Nuns: Irish Soccer Fandom as Performance.” Post-Celtic Tiger Irishness Symposium, Trinity College Dublin, 25 Nov. 2016.Dahlgren, Peter. “Beyond Information: TV News as a Cultural Discourse.” The European Journal of Communication Research 12.2 (1986): 125–36.Fanning, John. “Branding and Begorrah: The Importance of Ireland’s Nation Brand Image.” Irish Marketing Review 21.1-2 (2011). 25 Mar. 2017 <https://www.dit.ie/media/newsdocuments/2011/3%20Fanning.pdf>.Free, Marcus. “Diaspora and Rootedness, Amateurism and Professionalism in Media Discourses of Irish Soccer and Rugby in the 1990s and 2000s.” Éire-Ireland 48.1–2 (2013). 25 Mar. 2017 <https://muse.jhu.edu/article/510693/pdf>.Friedman, Thomas. “Foreign Affairs: The Lexus and the Shamrock.” The Opinion Pages. New York Times 3 Aug. 2001 <http://www.nytimes.com/2001/08/03/opinion/foreign-affairs-the-lexus-and-the-shamrock.html>.Gerbner, George. “The Stories We Tell and the Stories We Sell.” Journal of International Communication 18.2 (2012). 25 Mar. 2017 <http://dx.doi.org/10.1080/13216597.2012.709928>.Goldman, Robert, and Stephen Papson. Sign Wars: The Cluttered Landscape of Advertising. New York: Guilford Press, 1996.Negra, Diane. The Irish in Us. Durham, NC: Duke University Press, 2006.Pope, Whitney. “Emile Durkheim.” Key Sociological Thinkers. 2nd ed. Ed. Rob Stones. Hampshire: Palgrave Macmillan, 2008. 76-89.Poulton, Emma, and Martin Roderick. Sport in Films. London: Routledge, 2008.Rains, Stephanie. The Irish-American in Popular Culture 1945-2000. Dublin: Irish Academic Press, 2007.Rowe, David, Andy Ruddock, and Brett Hutchins. “Cultures of Complaint: Online Fan Message Boards and Networked Digital Media Sport Communities.” Convergence: The International Journal of Research into New Media Technology 16.3 (2010). 25 Mar. 2017 <http://journals.sagepub.com/doi/abs/10.1177/1354856510367622>.Rowe, David. Sport, Culture and the Media: The Unruly Trinity. 2nd ed. Berkshire: Open University Press, 2004.Stead, David. “Sport and the Media.” Sport and Society: A Student Introduction. 2nd ed. Ed. Barrie Houlihan. London: Sage, 2008. 328-347.Wardle, Claire. “Social Media, Newsgathering and the Olympics.” Journalism, Media and Cultural Studies 2 (2012). 25 Mar. 2017 <https://publications.cardiffuniversitypress.org/index.php/JOMEC/article/view/304>.