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For a second generation secure telephone system, Howard Rosenblum in 1967 proposed and patented a key distribution system that he called Bellfield. 2 When in the 1960s the NSA developed a secure telephone system these requirements presented a problem: since anyone with a phone capable of encryptionmightplaceacalltoanyothersuchphone, it seemed that there had to be an advance arrangement to share a unique encryption key between every potential pair of telephones. Thus, cryptographic communication requires advance planning to choose encryption and decryption keys and to distribute those keys to the sender and receiver using a secure communication method. The remainder of this discussion assumes use of symmetric encryption, which means that the encryption and decryption keys are either identical or derivable one from the other, so the secure communication of the keys must assure bothconfidentialityandintegrity. [Extracted from the article]

Today, the use of wearable devices is becoming a thing inherent in the daily activities of urban communities. In practice, wearable communications may contain sensitive information regarding a user's health record, so authentication and confidentiality of data exchanged must be guaranteed. In addition, the success of authentication between users, wearable devices and smartphones is very important because there are various threats of attack on the authentication process. Based on previous studies, it was found that the security functionality of user impersonation attack is not owned by lightweight authentication protocols in the current wearable communication environment. So this research undertakes the design of a lightweight authentication protocol to be immune to user impersonation attacks to supplement the lack of security functionality in previous protocols with the support of performing a formal analysis using the Scyther Tool. The research method used is a Research Library supported by conducting protocol security test experiment. The developed protocol utilizes a modified and customized S-NCI key establishment protocol scheme to meet all targeted security functionality. The research resulted that the lightweight authentication protocol generated was immune to the impersonation attacks of users, then was able to add two new functionalities that added wearable devices and added smartphones. [ABSTRACT FROM AUTHOR]

Quantum key distribution (QKD) is a promising technology that aims to solve the security problem arising from the advent of quantum computers. While the main theoretical aspects are well developed today, limited performances, in terms of the achievable link distance and the secret key rate, are preventing the deployment of this technology on a large scale. More recent QKD protocols, which use multiple degrees of freedom for encoding of the quantum states, allow enhancement of the system performances. Here, we present the experimental demonstration of the differential phase-time shifting protocol up to 170 km of the fiber link. We compare its performance with the well-known coherent one-way and differential phase shifting protocols, demonstrating a higher secret key rate up to 100 km. Moreover, we propagate a classical signal in the same fiber, proving the compatibility of quantum and classical light. [ABSTRACT FROM AUTHOR]

There are many marketing methods used to attract customers' attention and customers search for special discounts and conduct research to get products cheaper. Using discount coupons is one of the widely used methods for obtaining discounts. With the development of technology, classical paper-based discount coupons become e-coupons and then turn into mobile coupons (m-coupons). It is inevitable that retailers will use m-coupon technology to attract customers while mobile devices are used in daily life. As a result, m-coupon technology is a promising technology. One of the significant problems with using m-coupons is security. Here it is necessary to ensure the safety of the seller's and retailer's data and to prevent unnecessary loss of income. In this study, a new m-coupon protocol is proposed and analyzed against well-known attacks: impersonation, man-in-the-middle, eavesdropping, replay, data modification, unauthorized coupon copying/generation, and multiple cash-in attacks. Then, to show that both the client and the retailer's data are at the highest level of security, the protocol is subjected to security analysis with a powerful protocol analysis tool, Scyther. Thus, the proposed protocol is proved to meet all safety criteria. To the best of our knowledge, this protocol is the first m-coupon protocol for which formal security analysis is conducted by the protocol's developers. [ABSTRACT FROM AUTHOR]

Physically Unclonable Functions (PUFs) represent a promising security primitive due to their unclonability, uniqueness and tamper-evident properties, and have been recently exploited for device identification and authentication, and for secret key generation and storage purposes. In this paper, we present PHEMAP (Physical Hardware-Enabled Mutual Authentication Protocol), that allows to achieve mutual authentication in a one-to-many communication scenario, where multiple devices are connected to a sink node. The protocol exploits the recursive invocation of the PUF embedded on the devices to generate sequences (chains) of values that are used to achieve synchronization among communicating parties. We demonstrate that, under reasonable assumptions, PHEMAP is secure and robust against man-in-the-middle attacks and other common physical attacks. We discuss PHEMAP performance in several operation conditions, by measuring the efficiency of the protocol when varying some of the underlying parameters. Finally, we present an implementation of PHEMAP on devices hosting an FPGA belonging to the Xilinx Zynq-7000 family and embedding an Anderson PUF architecture, and show that the computation and hardware overhead introduced by the protocol makes it feasible for commercial mid-range devices. [ABSTRACT FROM AUTHOR]

Radio frequency identification (RFID) technology enables unique identification and tracking of the tag attached to an object. Widespread usage of RFID technologies in supply chain management (SCM) has drawn attention for developing security protocols to protect data stored in the tag. In SCM objects move from one place/department to another, the same RFID readers are not used throughout the supply chain. So, current reader delegates its access right to the new reader. When an object is moved inside the organization, delegation takes place between the readers. Many of the existing delegation protocols use trusted third party (TTP), which is practically difficult to incorporate or requires a keyed hash function/symmetric key encryption to be executed in the RFID tag, whereas tags are computationally intensive. Our work aims to simplify the delegation process by removing the usage of a TTP as well as eliminating reader-to-reader communication which avoids fixing the reader sequence in advance. Also, it preserves the security and privacy requirements for cloud-based applications. The proposed protocol withstands many attacks like tracing attack, tag impersonation attack, reader impersonation attack, and privacy attack. The proposed protocol not only resists the above-mentioned attacks but also achieves mutual authentication, anonymity property, and forward/backward secrecy. The proposed protocol is analyzed formally using GNY logic, which ensures that the protocol achieves mutual authentication. Performance analysis is carried out and it shows that our protocol is relatively better than the existing related schemes with respect to tag computation and communication cost. [ABSTRACT FROM AUTHOR]

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.’s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols. [ABSTRACT FROM AUTHOR]

In a multi-server authentication environment, a user only needs to register once at a central registration place before accessing the different services on the different registered servers. Both, from a user point of view as for the management and maintenance of the infrastructure, these types of environments become more and more popular. Smartcard- or smartphone-based approaches lead to more secure systems because they offer two- or three-factor authentication, based on the strict combination of the user’s password, the user’s biometrics and the possession of the device. In this paper, we propose an efficient anonymous authentication protocol in multiple server communication networks, called the EAAM protocol, which is able to establish user anonymity, mutual authentication, and resistance against known security attacks. The novelty of the proposed scheme is that it does not require a secure channel during the registration between the user and the registration center and is resistant to a curious but honest registration system. These features are established in a highly efficient way with the minimum amount of communication flows between user and server during the establishment of the secret shared key and by using light-weight cryptographic techniques such as Chebyshev chaotic map techniques and symmetric key cryptography. The performance and security of the protocol are analyzed and compared with the latest new proposals in this field. [ABSTRACT FROM AUTHOR]

The Internet as we currently recognise it was institutionally established in 1983 when all hosts connected to the then ARPANET were required to have adopted the relatively new Transmission Control Protocol/Internet Protocol (TCP/IP) technologies. Thirteen years later, in 1996, a replacement standard was established for the IP protocol, to resolve key anticipated technical problems. More than 20 years later, those technical problems have indeed arisen, and yet the "new" protocol, IPv6, is still not widely deployed. This paper explores technical and institutional aspects of this case in order to examine how the evolving contexts of infrastructure use may turn technological solutions into infrastructural problems. [ABSTRACT FROM AUTHOR]

Authenticated key exchange protocols represent an important cryptographic mechanism that enables several parties to communicate securely over an open network. Elashry, Mu, and Susilo proposed an identity-based authenticated key exchange (IBAKE) protocol where different parties establish secure communication by means of their public identities.The authors also introduced a new security notion for IBAKE protocols called resiliency, that is, if the secret shared key is compromised, the entities can generate another shared secret key without establishing a new session between them. They then claimed that their IBAKE protocol satisfies this security notion. We analyze the security of their protocol and prove that it has a major security flaw, which renders it insecure against an impersonation attack. We also disprove the resiliency property of their scheme by proposing an attack where an adversary can compute any shared secret key if just one secret bit is leaked. [ABSTRACT FROM AUTHOR]

Card-based cryptographic protocols can perform secure computation of Boolean functions. In 2013, Cheung et al. presented a protocol that securely produces a hidden AND value using five cards; however, it fails with a probability of 1/2. The protocol uses an unconventional shuffle operation called an unequal division shuffle; after a sequence of five cards is divided into a two-card portion and a three-card portion, these two portions are randomly switched so that nobody knows which is which. In this paper, we first show that the protocol proposed by Cheung et al. securely produces not only a hidden AND value but also a hidden OR value (with a probability of 1/2). We then modify their protocol such that, even when it fails, we can still evaluate the AND value in the clear. Furthermore, we present two five-card copy protocols (which can duplicate a hidden value) using unequal division shuffle. Because the most efficient copy protocol currently known requires six cards, our new protocols improve upon the existing results. We also design a general copy protocol that produces multiple copies using an unequal division shuffle. Furthermore, we show feasible implementations of unequal division shuffles by the use of card cases. [ABSTRACT FROM AUTHOR]

In this paper, the random access procedure of Universal Mobile Telecommunications System network is investigated. We have proposed a model based on communicating timed automata that represents the main functions related to the random access procedure including the user equipment, the base station (node B or BTS), and the channel. Then, we have used computational tree logic formula to specify the proprieties to be verified. The model and the formulas serve as inputs to the model checker, which is used as a verification engine, ie, UPPAAL and SPIN. The formal verification approach shows that the protocol has several drawbacks that may not be detected by simulation. [ABSTRACT FROM AUTHOR]

Network protocol vulnerability detection plays an important role in many domains, including protocol security analysis, application security, and network intrusion detection. In this study, by analyzing the general fuzzing method of network protocols, we propose a novel approach that combines network traffic analysis with the binary reverse engineering method. For network traffic analysis, the block-based protocol description language is introduced to construct test scripts, while the binary reverse engineering method employs the genetic algorithm with a fitness function designed to focus on code coverage. This combination leads to a substantial improvement in fuzz testing for network protocols. We build a prototype system and use it to test several real-world network protocol implementations. The experimental results show that the proposed approach detects vulnerabilities more efficiently and effectively than general fuzzing methods such as SPIKE. [ABSTRACT FROM AUTHOR]

User authentication over the Internet has long been an issue for Internet service providers and users. A good authentication protocol must provide high security and mutual authentication on both sides. In addition, it must balance security and usability, which has been shown in the literature to be a difficult problem. To solve this problem, we propose a novel mutual authentication protocol with high security and usability. The proposed protocol was developed for quick response code, a type of two-dimensional barcode that can be photographed and quickly decoded by smartphones. We implemented a prototype using the proposed mutual authentication protocol and demonstrated how the prototype improves usability in a mobile communication system. We also used the Gong-Needham-Yahalom logic with several well-known attack models to analyze the security of the proposed protocol, and we obtained satisfactory results. We expect that using the proposed protocol, Internet service providers will be able to provide a mutual authentication mechanism with high security and usability. [ABSTRACT FROM AUTHOR]

In this paper, we introduce probabilistic snap-stabilization . We relax the definition of deterministic snap-stabilization without compromising its safety guarantees. In an unsafe environment, a probabilistically snap-stabilizing algorithm satisfies its safety property immediately after the last fault; whereas its liveness property is only ensured with probability 1. We show that probabilistic snap-stabilization is more expressive than its deterministic counterpart. Indeed, we propose two probabilistic snap-stabilizing algorithms for a problem having no deterministic snap- or self-stabilizing solution: guaranteed service leader election in arbitrary anonymous networks. This problem consists in computing a correct answer to each process that initiates the question “Am I the leader of the network?,” i.e. , (1) processes always compute the same answer to that question and (2) exactly one process computes the answer true . Our solutions being probabilistically snap-stabilizing, the answers are only delivered within an almost surely finite time; however any delivered answer is correct, regardless the arbitrary initial configuration and provided the question has been properly started. [ABSTRACT FROM AUTHOR]

DTLS is a transport layer security protocol designed to provide secure communication over unreliable datagram protocols. Before starting to communicate, a DTLS client and server perform a specific handshake in order to establish a secure session and agree on a common security context. However, the DTLS handshake is affected by two relevant issues. First, the DTLS server is vulnerable to a specific Denial of Service (DoS) attack aimed at forcing the establishment of several half-open sessions. This may exhaust memory and network resources on the server, so making it less responsive or even unavailable to legitimate clients. Second, although it is one of the most efficient key provisioning approaches adopted in DTLS, the pre-shared key provisioning mode does not scale well with the number of clients, it may result in scalability issues on the server side, and it complicates key re-provisioning in dynamic scenarios. This paper presents a single and efficient security architecture which addresses both issues, by substantially limiting the impact of DoS, and reducing the number of keys stored on the server side to one unit only. Our approach does not break the existing standard and does not require any additional message exchange between DTLS client and server. Our experimental results show that our approach requires a shorter amount of time to complete a handshake execution and consistently reduces the time a DTLS server is exposed to a DoS instance. We also show that it considerably improves a DTLS server in terms of service availability and robustness against DoS attack. [ABSTRACT FROM AUTHOR]

SDN-based controller, which is responsible for the configuration and management of the network, is the core of Software-Defined Networks. Current methods, which focus on the secure mechanism, use qualitative analysis to estimate the security of controllers, leading to inaccurate results frequently. In this paper, we employ a quantitative approach to overcome the above shortage. Under the analysis of the controller threat model we give the formal model results of the APIs, the protocol interfaces, and the data items of controller and further provide our Threat/Effort quantitative calculation model. With the help of Threat/Effort model, we are able to compare not only the security of different versions of the same kind controller but also different kinds of controllers and provide a basis for controller selection and secure development. We evaluated our approach in four widely used SDN-based controllers which are POX, OpenDaylight, Floodlight, and Ryu. The test, which shows the similarity outcomes with the traditional qualitative analysis, demonstrates that with our approach we are able to get the specific security values of different controllers and presents more accurate results. [ABSTRACT FROM AUTHOR]

SACM (Structured Assurance Case Metamodel) is a standard for assurance case specification and exchange. It consists of an argumentation metamodel and an evidence metamodel for justifying that a system satisfies certain requirements. For assurance of safety-critical systems, SACM can be used to manage safety evidence and to specify safety cases. The standard is a promising initiative towards harmonizing and improving system assurance practices, but its suitability for safety evidence management needs to be further studied. To this end, this paper studies how SACM 1.1 supports this activity according to requirements from industry and from prior work. We have analysed the notion of evidence in SACM, its evidence lifecycle, the classes and associations of the evidence metamodel, and the link of this metamodel with the argumentation one. As a result, we have identified several improvement opportunities and extension possibilities in SACM. The notions of evidence and evidence assertion should be clarified, the overlaps between metamodel elements should be reduced, and a wider support to the lifecycle of the artefacts used as safety evidence could be provided. Addressing these aspects will allow SACM to better fit safety evidence management needs and practices, especially beyond the scope of a safety case. The results and the conclusions drawn are especially valuable for practitioners interested in SACM adoption and vendors interested in developing tool support for SACM-based safety evidence management. [ABSTRACT FROM AUTHOR]

Authentication schemes have been widely deployed access control and mobility management in various communication networks. Especially, the schemes that are based on multifactor authentication such as on password and smart card come to be more practical. One of the standard authentication schemes that have been widely used for secure communication over the Internet is session initiation protocol (SIP). The original authentication scheme proposed for SIP was vulnerable to some crucial security weaknesses. To overcome the security problems, various improved authentication schemes have been developed, especially based on elliptic curve cryptography (ECC). Very recently, Zhang et al. proposed an improved authentication scheme for SIP based on ECC using smart cards to overcome the security flaws of the related protocols. Zhang et al. claimed that their protocol is secure against all known security attacks. However, this paper indicates that Zhang et al. protocol is still insecure against impersonation attack. We show that an active attacker can easily masquerade as a legal server to fool users. As a remedy, we also improve Zhang et al. protocol by imposing a little extra computation cost. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Recently group-oriented applications over unsecure open networks such as Internet or wireless networks have become very popular. Thus, group communication security over unsecure open networks has become a vital concern. Group key establishment (GKE) protocols are used to satisfy the confidentiality requirement of a newly started communication session by the generation or sharing of an ephemeral common key between the group members. In this study, we analyze the computation and communication efficiency of GKE protocols. Besides confidentiality, the security characteristics of identification and integrity control are also required for all steps of the protocol implementations. Thus, the main contribution of this work is to provide the computation and communication efficiency analysis of the same GKE protocols along with the identification of the group entities and integrity control of messages during the protocol steps. The specific implementation and analysis of GKE protocols are performed by group key agreement (GKA) with pairing-based cryptography and group key distribution (GKD) with verifiable secret sharing, respectively. Finally, a comparison of GKA and GKD protocols on the basis of their strong points and cost characteristics are also provided to inform potential users. [ABSTRACT FROM AUTHOR]

In large-scale distributed systems, where adversarial attacks have extensive impact, authentication provides fortification against threats involving impersonation of entities and tampering of data. Towards this, we introduce the first tetrahedron (three-dimensional (3D)) based two-server Password Authenticated and Key Exchange (PAKE) protocol to represent text passwords. A 3D PAKE protocol is a hybrid cryptographic algorithm that requires two servers for authentication; one server engages with users and the other is hidden from the clients. A remarkable aspect of the proposed 3D PAKE protocol is that reclaiming password from the stored credentials is not possible when either one/both the servers gets compromised. In this paper, we discuss the properties of tetrahedron that mesh well with Diffie–Hellman key exchange protocol and elliptic curve cryptography encryption scheme and proved that the protocol is resistant against cryptographic attacks without the involvement of public key infrastructure. The proposed protocol is the first provably secure two-server PAKE protocol against an offline dictionary attack. [ABSTRACT FROM PUBLISHER]

Optical fiber communication network security is getting more and more prominent, while the optical fiber communication network monitoring is another challenges of the optical fiber communication network security. In order to Address Resolution Protocol key technology was used. In addition, design of optical fiber communication network detection system was also designed. [ABSTRACT FROM AUTHOR]

We propose two symmetrically-private information retrieval protocols based on quantum key distribution, which provide a good degree of database and user privacy while being flexible, loss-resistant and easily generalized to a large database similar to the precedent works. Furthermore, one protocol is robust to a collective-dephasing noise, and the other is robust to a collective-rotation noise. [ABSTRACT FROM AUTHOR]

Privacy-preserving set operations are a popular research topic. Despite a large body of literature, the great majority of the available solutions are two-party protocols and expect that each participant knows her input set in the clear. In this work, we put forward a new framework for secure multi-party set and multiset operations in which the inputs can be arbitrarily partitioned among the participants, knowledge of an input (multi)set is not required for any party, and the secure set operations can be composed and can also be securely outsourced to third-party computation providers. In this framework, we construct a comprehensive suite of secure protocols for set operations and their various extensions. Our protocols are secure in the information-theoretic sense and are designed to minimize the round complexity. We then also build support for multiset operations by providing (i) a generic conversion from a multiset to a set, which makes the protocols for set operations applicable to multisets and (ii) direct instantiations of multiset operations of improved performance. All of our protocols have communication and computation complexity of $$O(m \log m)$$ and logarithmic round complexity for sets or multisets of size m, which compares favorably with prior work. Practicality of our solutions is shown through experimental results, and novel optimizations based on set compaction allow us to improve performance of our protocols in practice. Our protocols are secure in both semi-honest and malicious security models. [ABSTRACT FROM AUTHOR]

Combinatorial methods can make software security testing much more efficient and effective than conventional approaches. [ABSTRACT FROM PUBLISHER]

This is the report on the Workshop on Flow-Based Network Management, held within the 37th IRTF NMRG meeting, during IETF 93, on 24th July 2015, in Prague, Czech Republic. Following the tradition of the IRTF NMRG, the workshop focused on technologies, developments, and challenges of using flow-level traffic measurements for network management. [ABSTRACT FROM AUTHOR]

Recently, a broadcasting multiple blind signature scheme based on quantum teleportation has been proposed for the first time. It is claimed to have unconditional security and properties of quantum multiple signature and quantum blind signature. In this paper, we analyze the security of the protocol and show that each signatory can learn the signed message by a single-particle measurement and the signed message can be modified at random by any attacker according to the scheme. Furthermore, there are some participant attacks and external attacks existing in the scheme. Finally, we present an improved scheme and show that it can resist all of the mentioned attacks. Additionally, the secret keys can be used again and again, making it more efficient and practical. [ABSTRACT FROM AUTHOR]

Covert channels are widely considered as a major risk of information leakage in various operating systems, such as desktop, cloud, and mobile systems. The existing works of modeling covert channels have mainly focused on using finite state machines (FSMs) and their transforms to describe the process of covert channel transmission. However, a FSM is rather an abstract model, where information about the shared resource, synchronization, and encoding/decoding cannot be presented in the model, making it difficult for researchers to realize and analyze the covert channels. In this paper, we use the high-level Petri Nets (HLPN) to model the structural and behavioral properties of covert channels. We use the HLPN to model the classic covert channel protocol. Moreover, the results from the analysis of the HLPN model are used to highlight the major shortcomings and interferences in the protocol. Furthermore, we propose two new covert channel models, namely: (a) two channel transmission protocol (TCTP) model and (b) self-adaptive protocol (SAP) model. The TCTP model circumvents the mutual inferences in encoding and synchronization operations; whereas the SAP model uses sleeping time and redundancy check to ensure correct transmission in an environment with strong noise. To demonstrate the correctness and usability of our proposed models in heterogeneous environments, we implement the TCTP and SAP in three different systems: (a) Linux, (b) Xen, and (c) Fiasco.OC. Our implementation also indicates the practicability of the models in heterogeneous, scalable and flexible environments. [ABSTRACT FROM AUTHOR]

In this paper, we provide a proof of unconditional security for a semi-quantum key distribution protocol introduced in a previous work. This particular protocol demonstrated the possibility of using X basis states to contribute to the raw key of the two users (as opposed to using only direct measurement results) even though a semi-quantum participant cannot directly manipulate such states. In this work, we provide a complete proof of security by deriving a lower bound of the protocol's key rate in the asymptotic scenario. Using this bound, we are able to find an error threshold value such that for all error rates less than this threshold, it is guaranteed that A and B may distill a secure secret key; for error rates larger than this threshold, A and B should abort. We demonstrate that this error threshold compares favorably to several fully quantum protocols. We also comment on some interesting observations about the behavior of this protocol under certain noise scenarios. [ABSTRACT FROM AUTHOR]

Duplicate address detection (DAD) is an important component of the address resolution protocol (ARP) and the neighbor discovery protocol (NDP). DAD determines whether an IP address is in conflict with other nodes. In traditional DAD, the target address to be detected is broadcast through the network, which provides convenience for malicious nodes to attack. A malicious node can send a spoofing reply to prevent the address configuration of a normal node, and thus, a denial-of-service attack is launched. This study proposes a hash method to hide the target address in DAD, which prevents an attack node from launching destination attacks. If the address of a normal node is identical to the detection address, then its hash value should be the same as the “Hash_64” field in the neighboring solicitation message. Consequently, DAD can be successfully completed. This process is called DAD-h. Simulation results indicate that address configuration using DAD-h has a considerably higher success rate when under attack compared with traditional DAD. Comparative analysis shows that DAD-h does not require third-party devices and considerable computing resources; it also provides a lightweight security resolution. [ABSTRACT FROM AUTHOR]

The SMEN protocol, proposed by Wu and Ustaoglu in 2009, has been considered to be secure as the authors claimed, and numerous theories are proposed based on this protocol. This paper analyzes the SMEN protocol and finds that this protocol is not resistant to the session corruption attack and the key compromise impersonation attack. Then, we propose an improved protocol with tight security reduction. Our improved protocol not only avoids the above attacks but also embraces the same efficiency as the SMEN protocol in terms of exponentiation. Besides, formal analysis of the improved protocol is presented by using the formal automatic security analysis tool Scyther. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Broadcast encryption (BE) schemes allow a sender to securely broadcast to any subset of members but require a trusted party to distribute decryption keys. Group key agreement (GKA) protocols enable a group of members to negotiate a common encryption key via open networks so that only the group members can decrypt the ciphertexts encrypted under the shared encryption key, but a sender cannot exclude any particular member from decrypting the ciphertexts. In this paper, we bridge these two notions with a hybrid primitive referred to as contributory broadcast encryption (ConBE). In this new primitive, a group of members negotiate a common public encryption key while each member holds a decryption key. A sender seeing the public group encryption key can limit the decryption to a subset of members of his choice. Following this model, we propose a ConBE scheme with short ciphertexts. The scheme is proven to be fully collusion-resistant under the decision $n$ -Bilinear Diffie-Hellman Exponentiation (BDHE) assumption in the standard model. Of independent interest, we present a new BE scheme that is aggregatable. The aggregatability property is shown to be useful to construct advanced protocols. [ABSTRACT FROM AUTHOR]

Fraglets represent an execution model for communication protocols that resembles the chemical reactions in living organisms. The strong connection between their way of transforming and reacting and formal rewriting systems makes a fraglet program amenable to automatic verification. Grounded on past work, this paper investigates feasibility of adopting fraglets as model for specifying security protocols and analysing their properties. In particular, we give concrete sample analyses over a secure RFID protocol, showing evolution of the protocol run as chemical dynamics and simulating an adversary trying to circumvent the intended steps. The results of our analysis confirm the effectiveness of the cryptofraglets framework for the model and analysis of security properties and eventually show its potential to identify and uncover protocol flaws. [ABSTRACT FROM AUTHOR]

With trillions of machines connecting to mobile communication networks to provide a wide variety of applications, supporting a massive number of machine-to-machine (M2M) communications devices has been considered an essential requirement for mobile operators. Meanwhile, cyber security is of paramount importance in M2M as all applications involving M2M cannot be widely accepted without security guarantees. In this article we focus on the standardization activities of 3GPP, especially group-based security for largescale M2M communications in 3GPP networks. We first introduce the main components of the machine-type communication (MTC) security architecture. Then we discuss several major challenges for group-oriented secure M2M communications in 3GPP systems, i.e. authentication signalling congestion and overload, and group message protection. Specifically, we identify the performance issues of authentication signalling congestion and overload in no/low mobility scenarios, and propose three group access authentication and key agreement protocols. Moreover, several 3GPP candidate solutions for group message protection are introduced. Finally, we present key issues and research directions related to group-based secure M2M communications, including security, privacy, and efficiency in mobility scenarios of MTC, and flexible and efficient group key management. [ABSTRACT FROM AUTHOR]

This article introduces a definition of privacy for Direct Anonymous Attestation schemes. The definition is expressed as an equivalence property which is suited to automated reasoning using Blanchet's ProVerif. The practicality of the definition is demonstrated by analysing the RSA-based Direct Anonymous Attestation protocol by Brickell, Camenisch & Chen. The analysis discovers a vulnerability in the RSA-based scheme which can be exploited by a passive adversary and, under weaker assumptions, corrupt issuers and verifiers. A security fix is identified and the revised protocol is shown to satisfy our definition of privacy. [ABSTRACT FROM AUTHOR]