Public key infrastructure provides a promising foundation for verifying the authenticity of communicating parties and transferring trust over the internet. The key issue in public key infrastructure is how to process certificate revocations. Previous research in this aspect has concentrated on the tradeoffs that can be made among different revocation options. No rigorous efforts have been made ...

PKIs are complex distributed systems that are responsible for giving users enough information to make reasonable trust judgments about one another. Since the currencies of PKI are trust and certificates, users who make trust decisions (often called relying parties) must do so using only some initial trust beliefs about the PKI and some pile of certificates (and other assertions) they received f...

The Shibboleth middleware from Internet2 provides a way for users at higher-education institutions to access remote electronic content in compliance with the inter-institutional license agreements that govern such access. To protect end-user privacy, Shibboleth permits users to construct attribute release policies that control what user credentials a given content provider can obtain. However, ...

One of the most promising uses of time-stamping technology lies in combining it with a public key infrastructure. A public-key infrastructure (PKI) consists of protocols, services, and standards supporting applications of public-key cryptography [1]. Public-key cryptography involves the use of a public and private key pair. Data encrypted with a public key can only be decrypted with its related...

Nigeria has had several housing programmes and policies geared towards the provision of housing her citizens since colonial era to the post-colonial period. The Nigerian Government had always been directly involved in the provision of housing for the public servants and with the advent of the public-private partnership initiative, the low-income public servants’ acceptability of this new housin...

Reducing harm from drug use lies at the intersection of public health, public policy, politics and policing. In an ideal world, evidence of public health gains achievable through new approaches or technologies should inform public policy, should help shape political agendas in support of policy change, which should translate into law and regulations - and then to their application. The goal of ...

In the recent past, a lot of work has been done in establishing public key infrastructures (PKIs) for electronic commerce (e-commerce) applications. Unfortunately, most of these PKIs can only be used to authenticate the participants of e-commerce applications; they can't be used to properly authorize the participants and to control access to system resources accordingly. Consequently, these PKI...

With this construction we show that MD5 collisions can be crafted easily in such a way that the principles underlying the trust in Public Key Infrastructure are violated. In particular we find it worrying that from one certificate alone it cannot be determined whether another, different certificate may exist with the same signature. For the second certificate the issuing Certification Authority...

Optimized Public Key Infrastructures are traditional PKI in which end users may optimize the signatures of their documents, replacing the signer’s validation data with Optimized Certificates (OC). OCs carry the signer’s identification and public key, but are issued for a specific time, i.e., fields notBefore and notAfter have the same value, thus there are no reasons to revoke them. The OC’s ce...