If you wish to join the NES, or an international grid project, as an individual user, you will first require a personal certificate. These can be obtained from the UK Certification Authority (CA), who issue certificates to anyone in the UK e-Science community. These certificates are trusted not just by the NES but by Grids all over the world.
A certificate is a way of identifying you to remote computers. It is simply a way of letting a resource know you are who you say you are (i.e. authenticate yourself). A Certificate can best be imagined as a “Digital Passport” which cannot be forged.
NEVER allow anyone else access to your Internet Browser. This will give them access to your certificate.
NEVER give anyone your certificate. Always keep it safe.
If you feel that any of the above happened to you, you should get your certificate revoked and apply for a new one.
You can find a summary of Certificate Obligations from "NES Certificate Leaflets" section of the NES Posters and Leaflets page.