  Digital certificates are used to secure international computation and data
storage grids used for e-Science projects, like the Worldwide Large Hadron
Collider Computing Grid. The International Grid Trust Federation has defined
the Grid Certificate Profile: a set of guidelines for digital certificates used
for grid authentication. We have designed and implemented a program and related
test suites for checking X.509 certificates against the certificate profiles
and policies relevant for use on the Grid. The result is a practical tool that
assists implementers and users of public key infrastructures to reach
appropriate trust decisions.
