Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Much has been written about theory and practice in the law, and the tension between practitioners and theorists. Judges do not cite theoretical articles often; they rarely "apply" theories to particular cases. These arguments are not revisited. Instead the Essay explores the working and interaction of theory and practice, practitioners and theorists. The Essay starts with a story about solving a legal issue using our intellectual tools - theory, practice, and their progenies: experience and "gut." Next the Essay elaborates on the nature of theory, practice, experience and "gut." The third part of the Essay discusses theories that are helpful to practitioners and those that are less helpful. The Essay concludes that practitioners theorize, and theorists practice. They use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ. Theory, practice, experience and "gut" help us think, remember, decide and create. They complement each other like the two sides of the same coin: distinct but inseparable.

Of Theory and Practice

This work has been partially supported by Ministerio de Ciencia e Innovacion (Spain) under the grant TEC2009-13964-C04-02 and Ministerio de Industria, Turismo y Comercio (Spain) in collaboration with CDTI and Telefonica I+D under the project Segur@ CENIT-2007 2004

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A Survey of the Elliptic Curve Integrated Encryption Scheme

Connecting vehicles securely and reliably is pivotal to the implementation of next generation ITS applications of smart cities. With continuously growing security threats, vehicles could be exposed to a number of service attacks that could put their safety at stake. To address this concern, both US and European ITS standards have selected Elliptic Curve Cryptography (ECC) algorithms to secure vehicular communications. However, there is still a lack of benchmarking studies on existing security standards in real-world settings. In this paper, we first analyze the security architecture of the ETSI ITS standard. We then implement the ECC based digital signature and encryption procedures using an experimental test-bed and conduct an extensive benchmark study to assess their performance which depends on factors such as payload size, processor speed and security levels. Using network simulation models, we further evaluate the impact of standard compliant security procedures in dense and realistic smart cities scenarios. Obtained results suggest that existing security solutions directly impact the achieved quality of service (QoS) and safety awareness of vehicular applications, in terms of increased packet inter-arrival delays, packet and cryptographic losses, and reduced safety awareness in safety applications. Finally, we summarize the insights gained from the simulation results and discuss open research challenges for efficient working of security in ITS applications of smart cities.

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Security in Intelligent Transport Systems for Smart Cities: From Theory to Practice

Security of Wireless Sensor Networks (WSNs) is a very crucial factor when deployed for reconnaissance in sensitive areas. The existing symmetric encryption schemes provide a good amount of security, but maintenance of keys is difficult. When asymmetric schemes are used, maintenance of keys is easier, but they provide a lesser degree of security when compared to symmetric encryption schemes. In order to cope up with these shortcomings, we propose to use an improved version of the hybrid encryption scheme, which is a combination of Advanced Encryption Standard (AES) and Elliptical Curve Cryptography (ECC) with cross encrypted keys for secure key exchange and node authentication and hybrid encryption for enhanced cipher-text security. In case of transmission in WSNs, Statistical Cooperative Diversity based on Alamouti code is the most commonly used transmission scheme. However, for an arbitrary number of sensors, Alamouti code limits the BER performance and energy is not distributed equally, thereby creating the energy-hole problem which leads to early dysfunction of the sensors and may eventually lead to dysfunction of the Wireless Sensor Network (WSN). Extended Cooperative Space-time Block Codes (ECBSTBCs), which are obtained from Alamouti code, have the same characteristics of Alamouti code with the energy being distributed equally among the active sensors. With these factors in mind, we propose to use ECBSTBC as the transmission scheme. The improved hybrid scheme is ideal for ECBSTBC based WSN due to the speed of operation and higher degree of security that it offers.

An improved AES-ECC hybrid encryption scheme for secure communication in cooperative diversity based Wireless Sensor Networks

The most popular encryption scheme based on elliptic curves is the Elliptic Curve Integrated Encryption Scheme ECIES, which is included in ANSI X9.63, IEEE 1363a, ISO/IEC 18033-2, and SECG SEC 1. These standards offer many ECIES options, not always compatible, making it difficult to decide what parameters and cryptographic elements to use in a specific deployment scenario. In this work, the authors show that a secure and practical implementation of ECIES can only be compatible with two of the four previously mentioned standards. They also provide the list of functions and options that must be used in such an implementation. Finally, they present the results obtained when testing this ECIES version implemented as a Java application, which allows them to offer some comments about the performance and feasibility of their proposed solution.

Security and Practical Considerations When Implementing the Elliptic Curve Integrated Encryption Scheme

Elliptic Curve Cryptography (ECC) can be used as a tool for encrypting data, creating digital signatures or performing key exchanges. In relation to encryption, the Elliptic Curve Integrated Encryption Scheme (ECIES) is the best known scheme based on ECC, and as such it has been included in several cryptographic standards. In the present work, we provide an extensive review and comparison of the versions of ECIES included in documents from ANSI, IEEE, ISO/IEC, and SECG, highlighting the main differences between them that can prevent implementations of ECIES from being fully interoperable.

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A comparison of the standardized versions of ECIES

Elliptic Curve Cryptography is one of the best options for protecting sensitive information. The lastest version of th e Java platform includes a cryptographic provider, named SunEC, that implements some elliptic curve operations and protocols. However, potential users of this provider are limited by the lack of information available. In this work, we present an extensive review of the SunEC provider and, in addition to that, we offer to the reader the complete code of three applications that will allow programmers to generate key pairs, perform key exchanges, and produce digital signatures with elliptic curves in Java.

Implementing ECC with Java Standard Edition 7

Elliptic curve cryptography (ECC) is based in one of the hardest arithmetic problems, the elliptic curve discrete logarithm problem, making ECC a reliable cryptographic technique. In addition to this advantage, ECC requires shorter keys compared to other public key algorithms, which suggests its use in low-end systems such as smart cards because of its efficiency and limited hardware requirements. Currently the leading smart card technology is Java card. Though both Java 2 standard edition (J2SE) 5.0 and Java card (JC) 2.2.1 include classes and interfaces making ECC available to Java programs, they are not complete, making it necessary to use additional, non-standard packages if the programmer wants to use ECC for different operations (digital signature, data encryption and decryption, etc.). In the present work, we provide a complete review of the state of the art of ECC in J2SE and Java card, with a complete list of operations available in both standard implementations and proprietary packages.

Elliptic curve cryptography: Java implementation issues

Elliptic Curve Cryptography (ECC) is a branch of public-key cryptography based on the arithmetic of elliptic curves. In the short life of ECC, most standards have proposed curves defined over prime finite fields satisfying the curve equation in the short Weierstrass form. However, some researchers have started to propose as a securer alternative the use of Edwards and Montgomery elliptic curves, which could have an impact in current ECC deployments. This contribution evaluates the performance of the three types of elliptic curves using some of the examples provided by the initiative SafeCurves and a Java implementation developed by the authors, which allows us to offer some conclusions about this topic.

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V. Gayoso Martínez

Papers

Security and Practical Considerations When Implementing the Elliptic Curve Integrated Encryption Scheme

A comparison of the standardized versions of ECIES

Implementing ECC with Java Standard Edition 7

Elliptic curve cryptography: Java implementation issues

Secure elliptic curves and their performance