Key Establishment

Providing security over open and large distributed networks has always been both intriguing and challenging. There is a great chance for malicious individuals to perform disruptive and unethical tasks. Malicious users may attempt to obtain valuable information. So we require "secure channel" over insecure network. The secure communication channel should achieve primary security goals like confidentiality, integrity, authentication and non-repudiation and shared session keys are incorporated for the purpose. Therefore, it is of great interest and most challenging to devise effective mechanisms to establish these shared session keys, called key distribution problem. Much work has been done in recent years on mechanisms for key establishment. Many cryptosystems rely on cryptographically secure keys and therefore have to deal with issues like key management. A number of key establishment protocols have been proposed by different researchers as solutions to the key distribution problem and password based scheme is one of them. A password is shared between the entities in password based schemes. However, because users choose small and frequently used words as passwords, these schemes are suffered from password guessing attacks. Especially these schemes are subject to offline dictionary attacks. This work focus on password based key establishment. Even though there are a lot of password based schemes, the LDH, enhanced LDH, and PP-TAKE seems to be widely accepted mechanisms. In this context, this study includes performance evaluation of the above mentioned protocols.

This paper addresses the problem of secure path key establishment in wireless sensor networks that uses the random key predistribution technique. Inspired by the recent proxy-based scheme in [1] and [2], we introduce a friend -based scheme for establishing pairwise keys securely. We show that the chances of finding friends in a neighbourhood are considerably more than that of finding proxies, leading to lower communication overhead. Further, we prove that the friendbased scheme performs better than the proxy-based scheme in terms of resilience against node capture.

Wireless sensor network(WSN) has a wide range of applications in military as well as in civilian services. Key predistribution is a challenging task in sensor networks. Because the neighbor of a node after the deployment of sensors is unknown. For secure communication, neighbors must posses a secret common key or there must exist a key-path among these nodes. In this paper we have discussed in brief about various key pre-distribution schemes for homogeneous sensor networks and we had analyzed merits and demerits for each of them. Among various schemes a suitable scheme can be chosen based on the requirement and the resource availability of the sensors.

In wireless roaming a mobile device obtains a service from some foreign network while being registered for the similar service at its own home network. However, recent proposals try to keep the service provider role behind the home network and let the foreign network create a tunnel connection through which all service requests of the mobile device are sent to and answered directly by the home network. Such Wireless Roaming via Tunnels (WRT) offers several (security) benefits but states also new security challenges on authentication and key establishment, as the goal is not only to protect the end-to-end communication between the tunnel peers but also the tunnel itself. In this paper we formally specify mutual authentication and key establishment goals for WRT and propose an efficient and provably secure protocol that can be used to secure such roaming session. Additionally, we describe some modular protocol extensions to address resistance against DoS attacks, anonymity of the mobile device and unlinkability of its roaming sessions, as well as the accounting claims of the foreign network in commercial scenarios.

Key establishment between any pair of nodes is an essential requirement for providing secure services in wireless sensor networks. Blom's scheme is a prominent key management scheme but its shortcomings include large computation overhead and memory cost. We propose a new scheme in this paper that modifies Blom's scheme in a manner that reduces memory and computation costs. This paper also provides the value for secure parameter t such that the network is resilient.

Key establishment between any pair of nodes is an essential requirement for providing secure services in wireless sensor networks. Blom's scheme is a prominent key management scheme but its shortcomings include large computation overhead and memory cost. We propose a new scheme in this paper that modifies Blom's scheme in a manner that reduces memory and computation costs. This paper also provides the value for secure parameter t such that the network is resilient.

In this paper, we discuss the remaining security risk of Wi-Fi AP spoofing with current AP joining approaches and how a new solution has been developed as part of the ULOOP project in order to be more user-friendly and secure. It was an important step for increased security because our evaluation shows that even computer aware users do not know or do not bother about this issue although it is a real risk that current approaches do not solve.

Group key management (GKM) is one of the most important issues in secure group communication (SGC). The existing GKM protocols fall into three typical classes: centralized group key distribution (CGKD), decentralized group key management (DGKM), and distributed/contributory group key agreement (CGKA). Serious problems remains in these protocols, as they require existence of central trusted entities (such as group controller or subgroup controllers), relaying of messages (by subgroup controllers), or strict member synchronization (for multiple round stepwise key agreement), thus suffering from the single point of failure and attack, performance bottleneck, or misoperations in the situation of transmission delay or network failure. We proposed a new class of GKM protocols: distributed group key distribution (DGKD) [1]. The new DGKD protocol solves the above problems and surpasses the existing GKM protocols in terms of simplicity, efficiency, scalability, and robustness. In this paper, we extend the conference paper [1] with detailed experiments and discussions. Also based on DGKD, we propose a new distributed dynamic conferencing scheme which enforces group/conference membership management. Due to its distributed feature without the requirement of a central control, the proposed scheme is well suited in wireless networks such as Mobile Ad-hoc Networks (MANETs).

Mobile and wireless technology is growing at a rapid rate. These advances have resulted in breakthroughs that have made feasible several prospects that were thought as impossible. Ad hoc networks are a consequence of the ceaseless research efforts in Mobile and Wireless networks. Ad hoc network is a class of wireless networks where there is no fixed infrastructure. Unlike traditional networks they do not have base stations to coordinate the activities of mobile hosts. In this paper we proposed the authentication scheme using CBRP in MANETS. Here we have explored the concept of MANETS in location database management with proper authentication. For this purpose we have presented a distributed network consisting of two clusters along with their cluster heads. KeywordsAuthentication, CBRP, Cluster,

Secure communications in wireless ad hoc networks are protected by setting up end-to-end secret keys for commu- nicating node pairs. Secret keys can be provided by pre-loading shared secrets (e.g. a set of potential keys or keying informa- tion) into nodes prior to deployment. However, due to physical limitations of nodes and network scalability requirements, this key pre-distribution approach is not able to achieve full key- connectivity for all communicating pairs. Therefore, on-demand key establishment, in which pairwise secret keys are derived by exchanging multiple keying messages among wireless nodes, becomes necessary. In this paper, we develop a theoretical framework for the on- demand key establishment approach. Our contributions include a novel security metric, which we call a Byzantine resilience vector, to quantify the resilience of any key establishment scheme against Byzantine (arbitrary) attacks. Our analysis shows that previous key establishment schemes are vulnerabl...

Since wireless sensor networks continue to grow in usage and many sensor-based systems reside in adversarial environments, security consideration is really vital for these systems. But one of the main challenges for the efficient distribution of security keys in wireless sensor networks is the resource scarcity. This paper presents an efficient Self Key Establishment protocol for Wireless sensor networks, nicknamed SKEW, in support of innetwork processing. We show that SKEW manages keys with less storage, communication, key transmission frequency, and computational overheads in comparison with similar protocols for the same purpose. All of these benefits are attained by usage of a very few number of messages for key distribution. Since SKEW preserves the network security even before start up time, it can well serve as a base security protocol for all types of security protocols in wireless sensor networks. In this protocol, none of the sensors in the network can send any packets without encryption. It also uses a key refreshing mechanism that prolongs the network security. Smart dust networks and pervasive computing environments can particularly benefit from the proposed protocol.

Many applications that make use of sensor networks require secure communication. Because asymmetric-key solutions are difficult to implement in such a resource-constrained environment, symmetric-key methods coupled with a priori key distribution schemes have been proposed to achieve the goals of data secrecy and integrity. These approaches typically assume that all nodes are similar in terms of capabilities and, hence, deploy the same number of keys in all sensors in a network to provide the aforementioned protections. In this paper, we demonstrate that a probabilistic unbalanced distribution of keys throughout the network that leverages the existence of a small percentage of more capable sensor nodes can not only provide an equal level of security, but also reduce the consequences of node compromise. To fully characterize the effects of the unbalanced key management system, we design, implement, and measure the performance of a complementary suite of key establishment protocols known as LIGER. Using their predeployed keys, nodes operating in isolation from external networks can securely and efficiently establish keys with each other. Should resources such as a backhaul link to a key distribution center (KDC) become available, networks implementing LIGER automatically incorporate and benefit from such facilities. Detailed experiments demonstrate that the unbalanced distribution in combination with the multimodal LIGER suite offers a robust and practical solution to the security needs in sensor networks.

Inner product encryption (IPE) is a new cryptographic primitive initially proposed by Abdalla et al. in 2015. IPE can be classified into public-key IPE and secret-key IPE. The currently proposed PK-IPE schemes cannot resist the following collusion attack: an invalid user that holds no private key can "buy" a combined key generated from multiple collusion adversaries, and the user can use this private key to decrypt a ciphertext. Furthermore, the user should not let the collusion adversaries know the ciphertext, and the collusion adversaries should not let the user learn their private keys. We present a new PK-IPE to resist such collusion attack. Our PK-IPE is proven secure under the selective-vector chosen-plaintext attack model. We formalize a selective vector collusion attack model to prove that our scheme is secure under this model.

The cross slot loaded patch antenna with inset feed is designed and fabricated on FR4 substrate to get deca band. This proposed antenna consists of a cross slot on a rectangular patch with inset feeding, on a dielectric substrate. The simulated results of proposed antenna have ten resonating frequencies (2.30, 3.90, 5.30, 6.10, 8.70, 10.0, 12.9, 14.10,16.20, 19.0 GHz) while measured results of proposed antenna have eleven resonating frequencies (2.3089, 4.1079, 5.3073, 6.2069, 8.8056, 10.1050, 11.8041, 12.5038,14.3028, 16.1019, 19.1004 GHz). The frequency bands are useful for S band, C band, X band, Ku band, K band and for LTE applications. Frequency bands like 2.30, 5.30, 8.70 can be useful for LTE applications while other frequency bands can be used for different applications such as WIFI, WiMAX, satellite communication, radar communication etc. The simulation for desired antenna is performed with the help of software HFSS.

Sensor networks are a fast-evolving technology used for a variety of applications, ranging from environmental monitoring to cyberphysical systems (CPS) and IoT, including applications designed to support smart cities. The widespread use of sensor networks rises new challenges to data management and storage. The development of data storage systems is a hard task due to the speci c nature of wireless sensor networks (WSNs) and the lack of a common general purpose development framework. Software component models provide an appropriate level of system abstraction, reducing the development complexity and improving productivity. In this paper we propose RCBM, a Reusable Component-based Model for wireless sensor network storage simulation. RCBM promotes software reuse from existing components to improve the e ciency of system development and evaluation. RCBM has been implemented on the NS2 simulator and experimental results show that RCBM is more exible than previous component-based models for WSNs. Due to its general-purpose approach, RCBM can be applied to develop simulation code for a wide range of WSN storage models, reducing the development e ort.

We consider the K-user interference channel with an external eavesdropper, with no eavesdropper's channel state information at the transmitters (CSIT). We determine the exact sum secure degrees of freedom (s.d.o.f.) for this channel by providing a new alignment based achievable scheme and a matching converse. Our results show that the lack of eavesdropper's CSIT does not have a significant impact on the optimal s.d.o.f. of the interference channel with an external eavesdropper, especially when the number of users is large.

This Paper briefly sketches out the usage of security system in Mobile Cloud Computing which is including the monitoring, recording, tracking and giving notification to the user. For encryption-decryption will use Elliptic Curve Cryptography (ECC). The functionality of re-encryption "tag" and "mark" for data access system for every legal user. It suggests the cloud computing based on encryption and decryption services with functional reencryption which the encrypted medical data could be accessed and decryption from anywhere by whomever that has the ability to access according to the access policy. This paper proposed the discussion of the idea of medical usage of the cloud computing and the security accessing data by people who has been authorized according to the access policy.

Common Randomness Generation (CRG) and Secret Key Establishment (SKE) are fundamental primitives that are used in information-theoretic coding and cryptography. We study these two problems over the two-way channel model of communication, introduced by Shannon. In this model, the common randomness (CK) capacity is defined as the maximum number of random bits per channel use that the two parties can generate. The secret key (SK) capacity is defined similarly when the random bits are also required to be secure against a passive adversary. We provide lower bounds on the two capacities. These lower bounds are tighter than those one might derive based on the previously known results. We prove our lower bounds by proposing a two-round, two-level coding construction over the two-way channel. We show that the lower bound on the common randomness capacity can also be achieved using a simple interactive channel coding (ICC) method. We furthermore provide upper bounds on these capacities and show that the lower and the upper bounds coincide when the two-way channel consists of two independent (physically degraded) one-way channels. We apply the results to the case where the channels are binary symmetric.

Common Randomness Generation (CRG) and Secret Key Establishment (SKE) are fundamental primitives that are used in information-theoretic coding and cryptography. We study these two problems over the two-way channel model of communication, introduced by Shannon. In this model, the common randomness (CK) capacity is defined as the maximum number of random bits per channel use that the two parties can generate. The secret key (SK) capacity is defined similarly when the random bits are also required to be secure against a passive adversary. We provide lower bounds on the two capacities. These lower bounds are tighter than those one might derive based on the previously known results. We prove our lower bounds by proposing a two-round, two-level coding construction over the two-way channel. We show that the lower bound on the common randomness capacity can also be achieved using a simple interactive channel coding (ICC) method. We furthermore provide upper bounds on these capacities and show that the lower and the upper bounds coincide when the two-way channel consists of two independent (physically degraded) one-way channels. We apply the results to the case where the channels are binary symmetric.

We study the problem of unconditionally secure Secret Key Establishment (SKE) when Alice and Bob are connected by two noisy channels that are eavesdropped by Eve. We consider the case that Alice and Bob do not have any sources of initial randomness at their disposal. We start by discussing special cases of interest where SKE is impossible and then provide a simple SKE construction over binary symmetric channels that achieves some rates of secret key. We next focus on the Secret Key (SK) capacity and provide lower and upper bounds on this capacity. We prove the lower bound by proposing a multi-round SKE protocol, called the main protocol. The main protocol consists of an initialization round and the repetition of a two-round SKE sub-protocol, called the basic protocol. We show that the two bounds coincide when channels do not leak information to the adversary. We apply the results to the case that communicants are connected by binary symmetric channels.

This paper considers the problem of information-theoretic Secret Key Establishment (SKE) in the presence of a passive adversary, Eve, when Alice and Bob are connected by a pair of independent discrete memoryless broadcast channels in opposite directions. We refer to this setup as 2DMBC. We define the secret-key capacity in the 2DMBC setup and prove lower and upper bounds on this capacity. The lower bound is achieved by a two-round SKE protocol that uses a two-level coding construction. We show that the lower and the upper bounds coincide in the case of degraded DMBCs.

The problem of Secret Key Establishment (SKE) over a pair of independent Discrete Memoryless Broadcast Channels (DMBCs) has already been studied in [3], where we provided lower and upper bounds on the secret-key capacity. In this paper, we study the above setup under each of the following two cases: (1) the DMBCs have secrecy potential, and (2) the DMBCs are stochastically degraded with independent channels. In the former case, we propose a simple SKE protocol based on a novel technique, called Interactive Channel Coding (ICC), and prove that it achieves the lower bound. In the latter case, we give a simplified expression for the lower bound and prove a single-letter capacity formula under the condition that one of the legitimate parties can only send i.i.d. variables.

Many applications that make use of sensor networks require secure communication. Because asymmetric-key solutions are difficult to implement in such a resource-constrained environment, symmetric-key methods coupled with a priori key distribution schemes have been proposed to achieve the goals of data secrecy and integrity. These approaches typically assume that all nodes are similar in terms of capabilities and, hence, deploy the same number of keys in all sensors in a network to provide the aforementioned protections. In this paper, we demonstrate that a probabilistic unbalanced distribution of keys throughout the network that leverages the existence of a small percentage of more capable sensor nodes can not only provide an equal level of security, but also reduce the consequences of node compromise. To fully characterize the effects of the unbalanced key management system, we design, implement, and measure the performance of a complementary suite of key establishment protocols known as LIGER. Using their predeployed keys, nodes operating in isolation from external networks can securely and efficiently establish keys with each other. Should resources such as a backhaul link to a key distribution center (KDC) become available, networks implementing LIGER automatically incorporate and benefit from such facilities. Detailed experiments demonstrate that the unbalanced distribution in combination with the multimodal LIGER suite offers a robust and practical solution to the security needs in sensor networks.

A well known result by Kilian (ACM 1988) asserts that general secure two computation (2PC) with statistical security, can be based on OT. Specifically, in the client-server model, where only one party-the client-receives an output, Kilian's result shows that given the ability to call an ideal oracle that computes OT, two parties can securely compute an arbitrary function of their inputs with unconditional security. Ishai et al. (EUROCRYPT 2011) further showed that this can be done efficiently for every two-party functionality in NC 1 in a single round. However, their results only achieve statistical security, namely, it is allowed to have some error in security. This leaves open the natural question as to which client-server functionalities can be computed with perfect security in the OT-hybrid model, and what is the round complexity of such computation. So far, only a handful of functionalities were known to have such protocols. In addition to the obvious theoretical appeal of the question towards better understanding secure computation, perfect, as opposed to statistical reductions, may be useful for designing secure multiparty protocols with high concrete efficiency, achieved by eliminating the dependence on a security parameter. In this work, we identify a large class of client-server functionalities f : X ×Y → {0, 1}, where the server's domain X is larger than the client's domain Y, that have a perfect reduction to OT. Furthermore, our reduction is 1-round using an oracle to secure evaluation of many parallel invocations of 1-out-of-2 bit OT, as done by Ishai et al. (EUROCRYPT 2011). Interestingly, the set of functions that we are able to compute was previously identified by Asharov (TCC 2014) in the context of fairness in two-party computation, naming these functions full-dimensional. Our result also extends to randomized non-Boolean functions f : X × Y → {0,. .. , k − 1} satisfying |X | > (k − 1) • |Y|.

Key management is very crucial need in WSN to protect data and secure communications. One of the Key distribution solutions in WSN is symmetric key cryptography which is relatively faster and energy efficient. However, it cannot bestow high level of security due to difficulty in secure key management. Nevertheless, Asymmetric key cryptography can enhance network security but it also causes energy, memory and computational overhead. In this paper we proposed Mobile Agent Based Dynamic Key Management Scheme. This scheme has two levels that exploit good features of asymmetric and symmetric cryptography respectively. In the first level we introduced agent based key distribution and coordination for asymmetric keys while the second level is sensor nodes can involve in constructing symmetric keys for secure communication through mutual authentication and encryption with those keys. Agent based public key dissemination and update of shared keys could reduce communication overhead. We evalu...

In this work we introduce a new method of cryptography based on the matrices over a finite field Fq, were q is a power of a prime number p. The first time we construct the matrix M = A 1 A 2 0 A 3 were A 1 , A 2 and A 3 are matrices of order n with coefficients in Fq and 0 is the zero matrix of order n. We prove that M l = A l 1

Let F q be the finite field of q elements, where q is a prime power. In this paper, we study the Montgomery curves over the ring F q [X] X 2 −X , denoted by M A,B (F q [X] X 2 −X); (A, B) ∈ (F q [X] X 2 −X) 2. Using the Montgomery equation, we define the Montgomery curves M A,B (F q [X] X 2 −X) and we give a bijection between this curve and product of two Montgomery curves defined on F q. Furthermore, we study the addition law of Montgomery curves over the ring F q [X] X 2 −X. We close this paper by introducing a public key cryptosystem which is a variant of the ElGamal cryptosystem on a Montgomery curves over the same ring.

Abstract: Transmission of confidential messages over wireless networks between a transmitter and a receiver in the presence of illegitimate receivers called eavesdroppers is an active area of research. Cooperation by jamming can improve information-theoretic secrecy in wireless networks. However, randomly chosen jammers can have a negative impact on the secrecy capacity. Our goal is to provide a closed form for positioning the friendly jammers in two-dimensional wireless network with uniformly distributed eavesdroppers while two legitimate partners are communicating.

Proving an identity over a public link is complex when there is communication between Client and Server. Secure Shell protocol is deployed, to determine a client's identity through Password-based key exchange schemes, over a public network, by sharing a (short) password only, with a session key. Most of the existing schemes are vulnerable to various dictionary attacks. SSL is the de facto standard today for securing end to end transport. While the protocol seems rather secure there are a number of risks which lurk in its use. The focus of the paper is on the analysis of very efficient schemes on password-based authenticated key-exchange methods. In this paper analysis of AuthA key exchange scheme and DH-EKE is done and complete proof of its security is generated. Evidences are generated to show that the AuthA and DH_EKE protocol and its multiple modes of operation are secure under the computational Diffie-Hellman intractability assumption and help in fortification of transport layer security protocol.

In this paper we propose a key pre-distribution scheme using combinatorial design. The network is assumed to be heterogeneous and the rectangular grid structure of the network is non-uniform. During key distribution phase, nodes are placed in the rectangular grid to form a virtual network. The actual network consists of the nodes along with their location in the target region. However, the deployment strategy and the key distribution technique indicate high connectivity of the network. Our scheme demonstrates superior performance compared to the existing similar schemes.

We propose a key pre-distribution scheme based on the complementary design of a Fano plane. The nodes are arranged hierarchically in the form of a 6-nary tree. Key predistribution follows a deterministic approach. Each node in our scheme requires storing significantly less number of secret keys. Our scheme provides better resiliency compared to other existing schemes and reasonable connectivity as well. It can be found that any two nodes are connected either directly or via a key-path. Moreover, any number of nodes can be introduced in the network by assigning a few keys to the newly joined nodes only, without disturbing the existing setup of the network.

In this paper we propose a key pre-distribution scheme using combinatorial design. The network is assumed to be heterogeneous and the rectangular grid structure of the network is non-uniform. During key distribution phase, nodes are placed in the rectangular grid to form a virtual network. The actual network consists of the nodes along with their location in the target region. However, the deployment strategy and the key distribution technique indicate high connectivity of the network. Our scheme demonstrates superior performance compared to the existing similar schemes.

We propose a key pre-distribution scheme based on the complementary design of a Fano plane. The nodes are arranged hierarchically in the form of a 6-nary tree. Key predistribution follows a deterministic approach. Each node in our scheme requires storing significantly less number of secret keys. Our scheme provides better resiliency compared to other existing schemes and reasonable connectivity as well. It can be found that any two nodes are connected either directly or via a key-path. Moreover, any number of nodes can be introduced in the network by assigning a few keys to the newly joined nodes only, without disturbing the existing setup of the network.

This paper proposes a three-phase transmission scheme to ensure zero secrecy outage in decode-and-forward relay systems by using the strategies of artificial noise (AN) injection and channel state information (CSI) leakage avoidance. The zero-outage secrecy spectral efficiency (ZOSSE) and energy efficiency (ZOSEE) of the scheme are then analyzed. Finally, the paper demonstrates that the scheme can always achieve zero secrecy outage even when the eavesdropper has an unlimited number of antennas or is in an arbitrary location, which shows its practical applicability. The paper also shows that the ZOSSE increases with the transmit power and that both the ZOSSE and the ZOSEE are maximized when the relay is halfway between the transmitter and the receiver. This suggests that the placement of the helper node is important in securing the communication of two distant nodes.

WLANs use air as a medium for transferring data between users. This medium permits the hackers listening and sniffing the transferred data from away distance without the need for a real physical connection. In this paper, the threats of different security levels, such as SSID, MAC filter, and WPA II used to ensure protection of WLANs are investigated. The structure and fundamental concept of every security mechanism are analyzed and discussed. The penetration test for cryptanalysis WPA II in the PSK mode, discovering hidden SSID, and bypassing MAC filter is illustrated experimentally. The assessment process is executed using the Kali Linux platform and many other tools.

At the moment, digital documents are just as important as paper documents. As a result, authenticity is essential, especially in legal situations and digital forensics. As technology advances, these digital signature algorithms become weaker, necessitating the development of digital authentication schemes capable of withstanding current security threats. This study proposed a scheme based on an asymmetric key cryptosystem and the user’s biometric credentials to generate keys for digital signatures. A single document can be signed by multiple signatories at the same time under this scheme. The primary goal of this article is to create a safe and cost-effective multiignature scheme. To create keys for document signing and verification, the Edwards-curve Digital Signature Algorithm (EdDSA), especially Ed25519, is employed. The Edwards-curve Digital Signature Algorithm is used with blockchain technology to sign crypto wallets. The Python implementation of a scheme that enables platform ...

Number theoretic public-key solutions, currently used in many applications worldwide, will be subject to various quantum attacks, making them less attractive for longer-term use. Certain group theoretic constructs are now showing promise in providing quantum-resistant cryptographic primitives, and may provide suitable alternatives for those looking to address known quantum attacks. In this paper, we introduce a new protocol called a Meta Key Agreement and Authentication Protocol (MKAAP) that has some characteristics of a public-key solution and some of a shared-key solution. Specifically it has the deployment benefits of a public-key system, allowing two entities that have never met before to authenticate without requiring real-time access to a third-party, but does require secure provisioning of key material from a trusted key distribution system (similar to a symmetric system) prior to deployment. We then describe a specific MKAAP instance, the Ironwood MKAAP, discuss its security, and show how it resists certain quantum attacks such as Shor's algorithm or Grover's quantum search algorithm. We also show Ironwood implemented on several "internet of things" (IoT devices), measure its performance, and show how it performs significantly better than ECC using fewer device resources.

Motivated by the problem of establishing a session key among parties based on the possession of certain credentials only, we discuss a notion of attribute-based key establishment. A number of new issues arise in this setting that are not present in the usual settings of group key establishment where unique user identities are assumed to be publicly available. After detailing the security model, we give a two-round solution in the random oracle model. As main technical tool we introduce a notion of attribute-based signcryption, which may be of independent interest. We show that the type of signcryption needed can be realized through the encrypt-then-sign paradigm. Further, we discuss additional guarantees of the proposed protocol, that can be interpreted in terms of deniability and privacy.

This letter studies the secure transmission protocol design for two-way cooperative systems, where two terminal users communicate via an untrusted relay. The relay acts as both a helper and a potential eavesdropper, from which the users' messages need to be kept secret. A constellation-rotation aided approach is proposed to prevent the relay from decoding these messages. By rotating the signal constellation with a proper angle, the complexvalued symbol can be fully represented by its real component. Then, either user utilizes only one dimension of the signal to deliver its information, with the other dimension carrying the artificial noise (AN). In this manner, the received signal-to-interference-plusnoise ratio (SINR) at the relay is degraded due to the injection of AN, thereby increasing the difficulty of eavesdropping. Moreover, the desired signal and the AN lie in different directions at the terminal users, which makes the signal detection free-of-interference. The approximate expression for the upper bound of the users' symbol error rate (SER) is derived based on which a criterion is developed to choose the rotation angle that can optimize the system SER performance. Simulation results demonstrate the superiority of our scheme compared to the competing candidates.

Secrecy rate maximization in Gaussian MIMO wiretap channels is considered. While the optimality of Gaussian signaling and a general expression for the secrecy capacity have been well established, closed-form solutions for the optimal transmit covariance matrix are known for some special cases only, while the general case remains an open problem. This chapter reviews known closed-form solutions and presents a numerical algorithm for the general case with guaranteed convergence to the global optimum. The known solutions include full-rank and rank-1 cases (which, when combined, provide a complete solution for the case of two transmit antennas), the case of identical right singular vectors for the eavesdropper and legitimate channels, and the cases of weak, isotropic, and omnidirectional eavesdroppers, which also provide lower and upper bounds to the general case. Necessary optimality conditions and a tight upper bound for the rank of the optimal covariance matrix in the general case are discussed. Sufficient and necessary conditions for the optimality of three popular signaling strategies over MIMO channels, namely, isotropic and zero-forcing signaling as well as water-filling over the legitimate channel eigenmodes, are presented. The chapter closes with a detailed description of a numerical globally convergent algorithm to solve the general case, and gives some illustrative examples.

Let E be an elliptic curve defined over Q given by an affine Weierstrass equation of the form (1) E : y 2 = x 3 + ax + b (a, b ∈ Z, x, y ∈ Q). Reducing the elliptic curve (1) modulo a sufficiently large prime p, we obtain an elliptic curve E p over F p. Considering an infinite sequence of elliptic curves E p , we map the point (x, y) of them into the unit square [0, 1) 2 via the mapping (x, y) → x p , y p. We prove that the obtained cumulative point set contains a point sequence aligning a line when E/Q has an integral point, and point sequences aligning lines of well defined number when E/Q has a rational point. In both cases, these lines contain infinitely many points being strictly monotone increasing or decreasing according to the L ∞ norm, and these monotone point sequences converge to well defined points.

Let E be an elliptic curve defined over Q given by an affine Weierstrass equation of the form (1) E : y 2 = x 3 + ax + b (a, b ∈ Z, x, y ∈ Q). Reducing the elliptic curve (1) modulo a sufficiently large prime p, we obtain an elliptic curve E p over F p. Considering an infinite sequence of elliptic curves E p , we map the point (x, y) of them into the unit square [0, 1) 2 via the mapping (x, y) → x p , y p. We prove that the obtained cumulative point set contains a point sequence aligning a line when E/Q has an integral point, and point sequences aligning lines of well defined number when E/Q has a rational point. In both cases, these lines contain infinitely many points being strictly monotone increasing or decreasing according to the L ∞ norm, and these monotone point sequences converge to well defined points.

This paper introduces SPOT, a Secure and Privacy-preserving prOximity based protocol for e-healthcare systems. It relies on a distributed proxy-based approach to preserve users' privacy and a semi-trusted computing server to ensure data consistency and integrity. The proposed protocol ensures a balance between security, privacy and scalability. As far as we know, in terms of security, SPOT is the first one to prevent malicious users from colluding and generating false positives. In terms of privacy, SPOT supports both anonymity of users being in proximity of infected people and unlinkability of contact information issued by the same user. A concrete construction based on structure-preserving signatures and NIWI proofs is proposed and a detailed security and privacy analysis proves that SPOT is secure under standard assumptions. In terms of scalability, SPOT's procedures and algorithms are implemented to show its efficiency and practical usability with acceptable computation and communication overhead.

One of the main challenges in pervasive computing is how we can establish secure communication over an untrusted high-bandwidth network without any initial knowledge or a Public Key Infrastructure. An approach studied by a number of researchers is building security though involving humans in a low-bandwidth "empirical" out-of-band channel where the transmitted information is authentic and cannot be faked or modified. A survey of such protocols can be found in [21]. Many protocols discussed there achieve the optimal amount of authentication for a given amount of human work. However it might still be attractive to attack them if a failed attack might be misdiagnosed as a communication failure and therefore remain undetected. In this paper we show how to transform protocols of this type to make such misdiagnosis essentially impossible.

This paper presents a square shape Split Ring Resonator (SRR) loaded with micro strip patch antenna operating in UWB (Ultra Wide Band) range (3.1GHz -10.6GHz) for Bio-medical applications. The Ultra-Wideband is a wireless technology which is used to send large data over a wide range of frequencies by using very narrow pulses at low PSD (Power Spectral Density). UWB provides wireless transmission of audio, video and data with wide bandwidth. The proposed antenna specifically operates at 4.1GHz and is designed on a 23.19mm x 23.19mm x 1.35mm board of Arlon AD1000 substrate. This SRR antenna has been simulated using High-Frequency Structure Simulator (HFSS) software. The results show enhanced performance in terms of high gain, return loss (<10dB), Voltage Standing Wave Ratio (VSWR)<2, low Specific Absorption Rate (SAR), high Directivity, high radiation Efficiency.

Internet of Things (IoT) offers new opportunities for business, technology and science but it also raises new challenges in terms of security and privacy, mainly because of the inherent characteristics of this environment: IoT devices come from a variety of manufacturers and operators and these devices suffer from constrained resources in terms of computation, communication and storage. In this paper, we address the problem of trust establishment for IoT and propose a security solution that consists of a secure bootstrap mechanism for device identification as well as a message attestation mechanism for aggregate response validation. To achieve both security requirements, we approach the problem in a confined environment, named SubNets of Things (SNoT), where various devices depend on it. In this context, devices are uniquely and securely identified thanks to their environment and their role within it. Additionally, the underlying message authentication technique features signature aggregation and hence, generates one compact response on behalf of all devices in the subnet.