95 research outputs found
Cryptanalysis of an Efficient Signcryption Scheme with Forward Secrecy Based on Elliptic Curve
The signcryption is a relatively new cryptographic technique that is supposed
to fulfill the functionalities of encryption and digital signature in a single
logical step. Several signcryption schemes are proposed throughout the years,
each of them having its own problems and limitations. In this paper, the
security of a recent signcryption scheme, i.e. Hwang et al.'s scheme is
analyzed, and it is proved that it involves several security flaws and
shortcomings. Several devastating attacks are also introduced to the mentioned
scheme whereby it fails all the desired and essential security attributes of a
signcryption scheme.Comment: 5 Pages, 2 Figure
LPKI - A Lightweight Public Key Infrastructure for the Mobile Environments
The non-repudiation as an essential requirement of many applications can be
provided by the asymmetric key model. With the evolution of new applications
such as mobile commerce, it is essential to provide secure and efficient
solutions for the mobile environments. The traditional public key cryptography
involves huge computational costs and is not so suitable for the
resource-constrained platforms. The elliptic curve-based approaches as the
newer solutions require certain considerations that are not taken into account
in the traditional public key infrastructures. The main contribution of this
paper is to introduce a Lightweight Public Key Infrastructure (LPKI) for the
constrained platforms such as mobile phones. It takes advantages of elliptic
curve cryptography and signcryption to decrease the computational costs and
communication overheads, and adapting to the constraints. All the computational
costs of required validations can be eliminated from end-entities by
introduction of a validation authority to the introduced infrastructure and
delegating validations to such a component. LPKI is so suitable for mobile
environments and for applications such as mobile commerce where the security is
the great concern.Comment: 6 Pages, 6 Figure
SSMS - A Secure SMS Messaging Protocol for the M-payment Systems
The GSM network with the greatest worldwide number of users, succumbs to
several security vulnerabilities. The short message service (SMS) is one of its
superior and well-tried services with a global availability in the GSM
networks. The main contribution of this paper is to introduce a new secure
application layer protocol, called SSMS, to efficiently embed the desired
security attributes in the SMS messages to be used as a secure bearer in the
m-payment systems. SSMS efficiently embeds the confidentiality, integrity,
authentication, and non-repudiation in the SMS messages. It provides an
elliptic curve-based public key solution that uses public keys for the secret
key establishment of a symmetric encryption. It also provides the attributes of
public verification and forward secrecy. It efficiently makes the SMS messaging
suitable for the m-payment applications where the security is the great
concern.Comment: 6 Pages, 5 Figure
A new approach to content-based file type detection
File type identification and file type clustering may be difficult tasks that
have an increasingly importance in the field of computer and network security.
Classical methods of file type detection including considering file extensions
and magic bytes can be easily spoofed. Content-based file type detection is a
newer way that is taken into account recently. In this paper, a new
content-based method for the purpose of file type detection and file type
clustering is proposed that is based on the PCA and neural networks. The
proposed method has a good accuracy and is fast enough.Comment: 6 Pages, 5 Figure, 2 Table
Effects of transverse shear deformations on the free vibration of anisotropic open circular cylindrical shells
Basic theory and method -- Fundamental equations for open cylindrical shells -- The displacement functions -- Determination of mass and stiffness matrices for an element -- Stiffness and mass matrices for the whole shell in vacuo -- Free vibration
Specialization of tendon mechanical properties results from interfascicular differences
Tendons transfer force from muscle to bone. Specific tendons, including the equine superficial digital flexor tendon (SDFT), also store and return energy. For efficient function, energy-storing tendons need to be more extensible than positional tendons such as the common digital extensor tendon (CDET), and when tested in vitro have a lower modulus and failure stress, but a higher failure strain. It is not known how differences in matrix organization contribute to distinct mechanical properties in functionally different tendons. We investigated the properties of whole tendons, tendon fascicles and the fascicular interface in the high-strain energy-storing SDFT and low-strain positional CDET. Fascicles failed at lower stresses and strains than tendons. The SDFT was more extensible than the CDET, but SDFT fascicles failed at lower strains than CDET fascicles, resulting in large differences between tendon and fascicle failure strain in the SDFT. At physiological loads, the stiffness at the fascicular interface was lower in the SDFT samples, enabling a greater fascicle sliding that could account for differences in tendon and fascicle failure strain. Sliding between fascicles prior to fascicle extension in the SDFT may allow the large extensions required in energy-storing tendons while protecting fascicles from damage
SMEmail - A New Protocol for the Secure E-mail in Mobile Environments
The electronic mail plays an unavoidable role in the humankind communications. With the great interest for the connection via mobile platforms, and the growing number of vulnerabilities and attacks, it is essential to provide suitable security solutions regarding the limitations of resource restricted platforms. Although some solutions such as PGP and S/MIME are currently available for the secure e-mail over the Internet, they are based on traditional public key cryptography that involves huge computational costs. In this paper, a new secure application-layer protocol, called SMEmail, is introduced that provides several security attributes such as confidentiality, integrity, authentication, non-repudiation, and forward secrecy of message confidentiality for the electronic mails. SMEmail offers an elliptic curve-based public key solution that uses public keys for the secure key establishment of a symmetric encryption, and is so suitable for the resource restricted platforms such as mobile phones
GEOMETRICALLY NON-LINEAR DYNAMIC ANALYSIS OF ARISOTROPIC LAMINATED OPEN CYLINDRICAL SHELLS WITH A REFINED SHELL THEORY.
NRC publication: Ye
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