In new distributed, key-oriented access control systems such as SPKI, access right are delegated by a freely formed network of certificates. We formalize the concept of a delegation network and present a formal semantics for the delegation of access rights with certificates. The certificates can have multiple subjects who must co-operate to use the authority. Some fundamental properties of the ...

In this paper, we give novel certificates for triangular equivalence and rank profiles. These certificates enable to verify the row or column rank profiles or the whole rank profile matrix faster than recomputing them, with a negligible overall overhead. We first provide quadratic time and space non-interactive certificates saving the logarithmic factors of previously known ones. Then we propos...

Vertex and edge connectivity are special cases of mixed connectivity, in which all edges and a specified set of vertices play a similar role. Certificates of k-connectivity for a graph are obtained by removing a subset of its edges, while preserving its connectivity up to k. We unify the previous work on connectivity certificates and extend it to handle mixed connectivity and multigraphs. Our t...

Vehicular network security is an important field and it is agreed that digital signature certificates are becoming the main authentication technique in this environment. The high number of vehicles and their continuous location change bring some difficulties in the exchange of these certificates and in their revocation. This paper covers these two cases and proposes an enhancement to the certif...

A certificate is a mathematical object that establishes the validity of a logical formula and that is self-contained, self-explanatory, and can be checked independently and automatically. Certificates arise naturally in many areas of mathematics, and in many different forms. In particular, certificates are common in the context of program verification, where they are used for automatic checking...

Draft revised stillbirth and early infant death certificates were sent with a short questionnaire to certifying doctors for 206 stillbirths and 198 neonatal deaths for which death certificates had been received in the Office of Population Censuses and Surveys over a three week period in 1982. The new certificates complied with the recommendations of the World Health Organisation and asked for d...

Browsers can detect malicious websites that are provisioned with forged or fake TLS/SSL certificates. However, they are not so good at detecting malicious websites if they are provisioned with mistakenly issued certificates or certificates that have been issued by a compromised certificate authority. Google proposed certificate transparency which is an open framework to monitor and audit certif...

Farkas’ lemma is a fundamental result from linear programming providing linear certificates for infeasibility of systems of linear inequalities. In semidefinite programming, such linear certificates only exist for strongly infeasible linear matrix inequalities. We provide nonlinear algebraic certificates for all infeasible linear matrix inequalities in the spirit of real algebraic geometry: A l...

In JDK 1.2, the security architecture supports fine grained access control. In the default implementation, Java runtime modules (classes) are signed, and permissions are configured through a configuration file using the signer’s identity and the loading location (URL) of the module. In a large network, the number of applets and the frequency of changes to the security policy will eventually gro...

STUDY OBJECTIVE The aim was to report on the extent to which death certificates which specify that death occurred in hospital can be matched and linked with routine hospital inpatient information systems. DESIGN The study involved linkage of hospital records which specified that death occurred in hospital to corresponding death certificates; and linkage of death certificates which specified t...