14 research outputs found
Certificateless and provably-secure digital signature scheme based on elliptic curve
With the internet today available at the user’s beck, and call data or Information Security plays a vital role. Confidentiality, Integrity, Availability, and Non-repudiation are the pillars of security on which every application on the web is based on. With these basic requirements the users also need the security in low resource constrained environments making it more challenging for the security experts to design secured cryptographic algorithms. Digital Signatures play a pivotal role in Authentication. They help in verifying the integrity of the data being exchanged. Elliptical curves are the strongest contenders in Digital Signatures, and much research is being done to enhance the method in many ways. The paper briefs a secured and improved ECDSA Elliptical Curve Digital Signature Algorithm which is an improved and secured version of the Digital Signature Algorithm
Cryptanalysis of a certificateless aggregate signature scheme
Recently, Nie et al. proposed a certificateless aggregate signature scheme. In the standard security model considered in certificateless
cryptography, we are dealing with two types of adversaries. In this paper, we show that Nie et al.\u27s scheme is insecure against the
adversary of the first type. In other words, although they claimed that their proposed scheme is existentially unforgeable against
adaptive chosen message attack considering the adversaries in certificateless settings, we prove that such a forgery can be done
TOWARD CERTIFICATELESS SIGNCRYPTION SCHEME WITHOUT RANDOM ORACLES
Signcryption is a useful paradigm which simultaneously offers both the functions of encryption and signature in a single logic step. It would be interesting to make signcryption certificateless to ease the heavy burden of certificate management in traditional public key cryptography (PKC) and solve the key escrow problem in Identity-based public key cryptography (ID-PKC). Most certificateless signcryption (CL-SC) schemes are constructed in the random oracle model instead of the standard model. By exploiting Bellare and Shoup\u27s one-time signature, Hwang et al.\u27s certificateless encryption and Li et al.\u27s identity-based signcryption, this paper proposes a new CL-SC scheme secure in the standard model. It is proven that our CL-SC scheme satisfies semantic security and unforgeability against the outside adversary and malicious-but-passive key generation center (KGC) assuming the hardness of bilinear decision Diffie-Hellman (BDDH) and computational Diffie-Hellman (CDH) problems. Our security proofs do not depend on random oracles
Selected Papers from the First International Symposium on Future ICT (Future-ICT 2019) in Conjunction with 4th International Symposium on Mobile Internet Security (MobiSec 2019)
The International Symposium on Future ICT (Future-ICT 2019) in conjunction with the 4th International Symposium on Mobile Internet Security (MobiSec 2019) was held on 17–19 October 2019 in Taichung, Taiwan. The symposium provided academic and industry professionals an opportunity to discuss the latest issues and progress in advancing smart applications based on future ICT and its relative security. The symposium aimed to publish high-quality papers strictly related to the various theories and practical applications concerning advanced smart applications, future ICT, and related communications and networks. It was expected that the symposium and its publications would be a trigger for further related research and technology improvements in this field
Cryptographic Schemes based on Elliptic Curve Pairings
This thesis introduces the concept of certificateless public key
cryptography (CLPKC). Elliptic curve pairings are then used to
make concrete CL-PKC schemes and are also used to make other
efficient key agreement protocols.
CL-PKC can be viewed as a model for the use of public key cryptography
that is intermediate between traditional certificated PKC and ID-PKC.
This is because, in contrast to traditional public key cryptographic
systems, CL-PKC does not require the use of certificates to guarantee
the authenticity of public keys. It does rely on the use of a trusted
authority (TA) who is in possession of a master key. In this
respect, CL-PKC is similar to identity-based public key
cryptography (ID-PKC). On the other hand, CL-PKC does not suffer
from the key escrow property that is inherent in ID-PKC.
Applications for the new infrastructure are discussed.
We exemplify how CL-PKC schemes can be constructed by constructing
several certificateless public key encryption schemes and
modifying other existing ID based schemes. The lack of
certificates and the desire to prove the schemes secure in the
presence of an adversary who has access to the master key or has
the ability to replace public keys, requires the careful
development of new security models. We prove that some of our
schemes are secure, provided that the Bilinear Diffie-Hellman
Problem is hard.
We then examine Joux’s protocol, which is a one round, tripartite
key agreement protocol that is more bandwidth-efficient than any
previous three-party key agreement protocol, however, Joux’s protocol
is insecure, suffering from a simple man-in-the-middle attack. We
show how to make Joux’s protocol secure, presenting several tripartite,
authenticated key agreement protocols that still require only one round
of communication. The security properties of the new protocols are
studied. Applications for the protocols are also discussed
Research Philosophy of Modern Cryptography
Proposing novel cryptography schemes (e.g., encryption, signatures, and protocols) is one of the main research goals in modern cryptography. In this paper, based on more than 800 research papers since 1976 that we have surveyed, we introduce the research philosophy of cryptography behind these papers. We use ``benefits and ``novelty as the keywords to introduce the research philosophy of proposing new schemes, assuming that there is already one scheme proposed for a cryptography notion. Next, we introduce how benefits were explored in the literature and we have categorized the methodology into 3 ways for benefits, 6 types of benefits, and 17 benefit areas. As examples, we introduce 40 research strategies within these benefit areas that were invented in the literature. The introduced research strategies have covered most cryptography schemes published in top-tier cryptography conferences
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A novel authentication protocol based on biometric and identity-based cryptography
Recently, considerable attention has been devoted to distributed systems. It has become obvious that a high security level should be a fundamental prerequisite for organisations' processes, both in the commercial and public sectors. A crucial foundation for securing a network is the ability to reliably authenticate ommunication parties. However, these systems face some critical security risks and challenges when they attempt to stabilise between security, efficiency and functionality. Developing a secure authentication protocol can be challenging; this thesis proposes an authentication scheme that employs two authentication factors involving something you know (password) and something you are (biometric) based on Identity-Based Cryptography and Elliptic Curve Cryptography. Two protocols have been chosen that provide mutual authentication and secure key exchange, which are the equivalent to the Diffie-Hellman key exchange. Due to a potential flaw in the protocols, guarding against attacks can be challenging. In order to alleviate some of the issues encountered with the new protocol, this thesis uses the encrypt-then-authenticate method. Formal verification methods are used to evaluate the new protocol. First, finite-state machines are used to examine and predict the behaviour of the protocol. Modelling with this method shows that the new protocol can function correctly and behave correctly within the protocol description, even with invalid input or time delay. Second, Petri nets are used to model, simulate and analyse the new protocol. This thesis formulates several attack models via Petri nets in which the security of the proposed protocols is discussed precisely. Ultimately, this novel work ensures that the new protocol provides a coherent security concept and can be implemented over insecure channels while offering secure mutual authentication
Authentication Protocols for Internet of Things: A Comprehensive Survey
In this paper, a comprehensive survey of authentication protocols for Internet of Things (IoT) is presented. Specifically more than forty authentication protocols developed for or applied in the context of the IoT are selected and examined in detail. These protocols are categorized based on the target environment: (1) Machine to Machine Communications (M2M), (2) Internet of Vehicles (IoV), (3) Internet of Energy (IoE), and (4) Internet of Sensors (IoS). Threat models, countermeasures, and formal security verification techniques used in authentication protocols for the IoT are presented. In addition a taxonomy and comparison of authentication protocols that are developed for the IoT in terms of network model, specific security goals, main processes, computation complexity, and communication overhead are provided. Based on the current survey, open issues are identified and future research directions are proposed
New Security Definitions, Constructions and Applications of Proxy Re-Encryption
La externalización de la gestión de la información es una práctica cada vez más común, siendo la computación en la nube (en inglés, cloud computing) el paradigma más representativo. Sin embargo, este enfoque genera también preocupación con respecto a la seguridad y privacidad debido a la inherente pérdida del control sobre los datos. Las soluciones tradicionales, principalmente basadas en la aplicación de polÃticas y estrategias de control de acceso, solo reducen el problema a una cuestión de confianza, que puede romperse fácilmente por los proveedores de servicio, tanto de forma accidental como intencionada. Por lo tanto, proteger la información externalizada, y al mismo tiempo, reducir la confianza que es necesario establecer con los proveedores de servicio, se convierte en un objetivo inmediato. Las soluciones basadas en criptografÃa son un mecanismo crucial de cara a este fin.
Esta tesis está dedicada al estudio de un criptosistema llamado recifrado delegado (en inglés, proxy re-encryption), que constituye una solución práctica a este problema, tanto desde el punto de vista funcional como de eficiencia. El recifrado delegado es un tipo de cifrado de clave pública que permite delegar en una entidad la capacidad de transformar textos cifrados de una clave pública a otra, sin que pueda obtener ninguna información sobre el mensaje subyacente. Desde un punto de vista funcional, el recifrado delegado puede verse como un medio de delegación segura de acceso a información cifrada, por lo que representa un candidato natural para construir mecanismos de control de acceso criptográficos. Aparte de esto, este tipo de cifrado es, en sà mismo, de gran interés teórico, ya que sus definiciones de seguridad deben balancear al mismo tiempo la seguridad de los textos cifrados con la posibilidad de transformarlos mediante el recifrado, lo que supone una estimulante dicotomÃa.
Las contribuciones de esta tesis siguen un enfoque transversal, ya que van desde las propias definiciones de seguridad del recifrado delegado, hasta los detalles especÃficos de potenciales aplicaciones, pasando por construcciones concretas