Mobile ad-hoc networks have various implementation constraints such as infrastructure-free, non-trusted authority, node mobility, and the limited power and small memory of mobile device. And just like wired networks, various security issues such as authentication, confidentiality, integrity, non-repudiation, access control, availability, and so on, have been arisen in the mobile ad-hoc networks...

Public Key Infrastructure is identified as the essential architecture upon which security and trust are built, in order to provide authentication, identity verification, encryption and non-repudiation in electronic transactions. Cross border availability of e-government services requires such a security infrastructure to provide a horizontal level of service across all implicated entities. This...

A convertible authenticated encryption scheme simultaneously provides the functions of integration, authentication, confidentiality, and non-repudiation. In this paper, we first separately point out that any adversary can forge a converted signature in Araki’s scheme and MaChen’s scheme. Moreover, we further improve the weakness in WuHsu’s scheme, which is to convert the signature into an ordin...

Content security requires authenticity given by integrity checks, authentication and non-repudiation. This can be achieved by using digital signatures. This paper presents a new semi-fragile steganographic technique for embedding digital signatures in images. This is achieved by using a novel modified Bit-Plane Complexity Segmentation (BPCS) Based Steganography scheme. Semi-fragile implies surv...

This memo describes how to incorporate the IDEA (International Data Encryption Algorithm) [IDEA] encryption algorithm into S/MIME (Secure/Multipurpose Internet Mail Extensions) [SMIME2, SMIME3]. The S/MIME standard provides a consistent way to send and receive secure MIME [MIME] data. Information security services are implemented on the basis of a set of cryptographic functions. Thus, digital s...

Authentication, non-repudiation, and digital signatures, require the ability to determine if a data token existed at a certain moment in time when the creator’s credentials were valid. Time-stamps are tokens which contain a verifiable cryptographic link between a time value and a data representation. The paper presents some critical aspects of the X.509 Public Key Infrastructure Time Stamp Prot...

We present an architecture called Accredited DomainKeys, which builds on the DomainKeys email authentication infrastructure to address the following questions: • “Did the sender actually send this email?” • “Is the sender of this email trustworthy?” The proposed DomainKeys architecture already addresses the first question but not the second. Accredited DomainKeys strengthens the reliability of ...

In order to be considered secure, a payment system needs to address a number of security issues. Besides fundamental security requirements, like confidentiality, data integrity, authentication and non-repudiation, another important requirement for a secure payment system is fair exchange. Many existing payment protocols require that customers must pay for products before their delivery (in the ...

We propose cryptographic protocols for electronic payment transactions over the Internet. Three essential requirements are met. (1) Security: this consists of entity authentication of each party involved, message integrity protection, strong non-repudiation on payment order and high degree of fault tolerance. (2) Economy: a payment transaction will be completed with the involvement of the conve...

------------------------------------------------------------------ABSTRACT----------------------------------------------------------------Digital signature scheme is an important research topic in cryptography. An ordinary digital signature scheme allows a signer to create signatures of documents and the generated signatures can be verified by any person. A proxy signature scheme, a variation o...