Public-key authentication based on public-key certiicates is a special case of the general problem of verifying a hypothesis (that a public key is authentic), given certain pieces of evidence. Beginning with PGP, several authors have pointed out that trust is often an uncertain piece of evidence and have proposed ad hoc methods, sometimes referred to as trust management, for dealing with this k...

As more and more companies conduct business with each other over the Internet, interoperable trust frameworks become important. For many businesses, trust provision is a critical issue in commencing B2B commerce transactional services. Communication over the Internet is by default open and uncontrolled and conflicts with the business needs of digital business. Privacy, confidentiality and integ...

The trustworthiness of any Public Key Infrastructure (PKI) rests upon the expectations for trust, and the degree to which those expectations are met. Policies, whether implicit as in PGP and SDSI/SPKI or explicitly required as in X.509, document expectations for trust in a PKI. The widespread use of X.509 in the context of global e-Science infrastructures, financial institutions, and the U.S. F...

A basic function of all signatures, digital or not, is to express trust and authority, explicit or implied. This is especially the case with digital signatures used in certificates. In this paper, we study the trust relationships expressed by the certificates used in X.509, PGP and SPKI. Especially, we present and revise the idea of a certificate loop, or a loop of certificates from the verifyi...

patient and user choice are at the forefront of the debate on the future direction of health and public services provision in many industrialized countries in europe and elsewhere. it is used both, as a means to achieve desired policy goals in public health care systems such as greater efficiency and improved quality of care, and as a good with its own intrinsic value. however, the evidence sug...

The paper describes methods for generating image watermark for asymmetric key based watermark embedding and detection scheme in wavelet domain. The proposed method combines DWT-based watermarking and the ability to verify watermark using reliable methods of asymmetric coding. The watermark scheme is developed to be directly incorporated into JPEG2000 image coding standard, while it can be used ...

DHCP is one of the most used network protocols, despite the security issues it has. Our work is motivated by the numerous attacks that can be launched against DHCP and the impact that they can have. Firstly, we formulate the constraints and design principles for a DHCP message authentication module that is flexible and easy to integrate with current DHCP implementations, while providing the nec...

Public-key authentication based on public-key certificates is a special case of the general problem of verifying a hypothesis (that a public key is authentic), given certain pieces of evidence. Beginning with PGP, several authors have pointed out that trust is often an uncertain piece of evidence and have proposed ad hoc methods, sometimes referred to as trust management, for dealing with this ...