Minimum CA Requirements
having one Certification Authority (CA)
organisation per country or large region (5-20M people) The goal is to serve the largest possible community with a
small number of stable CAs. To achieve sustainability, it is expected that the
CAs will be operated as a long-term commitment by institutions or organisations
rather than being bound to specific projects.
The CA structure within each country
should not follow the
conventional , where there is a chain of CAs. The model followed
simulates the hierarchical model , but there should be a single
end-entity issuing CA. A wide network of Registration Authorities (RA) for each
The RAs will handle the tasks of validating the identity of the end entities
and authenticating their requests, which will then be forwarded at the national/regional
CA. The CA will handle the actual tasks of issuing CRLs, signing
Certificates/CRLS and revoking Certificates when necessary.
The CA computer, where the signing of the certificates
will take place,
Each CA must sign only a well-defined namespace that
does not clash with any other
Every CA must have a Certification Policy and
Certificate Practice Statement (CP/CPS Document) and assign it an O.I.D.
Whenever there is a change in the CP/CPS the O.I.D. of the document must change
and the changes
must be announced to the EUGridPMA
for approv al
before signing any certs under the new CP/CPS. All the
CP/CPS under which valid certs are issued MUST be available on the web.
The CA Key must have a minimum length of 2048 bits and
less than two times of the maximum life time of an end entity certificate and
should not be more than 20 years.
The private key of the CA must be protected with a pass phrase of at least 15 elements which is known only by specific personnel of the Certification Authority. Copies of the encrypted private key must be kept on offline mediums in secure places where access is controlled.
The pass phrase of the encrypted private key must be kept also on an offline medium, separated from the encrypted keys and guarded in a safe place where only the authorized personnel of the Certification Authority have access. Alternatively, another documented procedure that is equally secure may be used.
The CA certificate must have the extensions keyUsage and basicConstraints marked as critical.
The CA must publish a CRL. The CA must react as soon as possible, but within one working day, to any revocation request received. After determining its validity, a CRL must be issued immediately. For CAs issuing certificates to end-entities, the maximum CRL lifetime must be at most 30 days and the CA must issue a new CRL at least 7 days before expiration and immediately after a revocation. The CRLs must be published in a repository at least accessible via the World Wide Web, as soon as issued.
Revocation requests can be made by end-entities, Registration Authorities and the CA. These requests must be properly authenticated. Others can request revocation if they can sufficiently prove compromise or exposure of the associated private key.
End-entities must request revocation if the private key pertaining to the certificate is lost or has been compromised, or if the data in the certificate are no longer valid.
The CA must record and archive all requests for certificates, along with all the issued certificates, all the requests for revocation, all the issued CRLs and the login/logout/reboot of the issuing machine.
private signing key must be changed periodically; from that time on only the
new key will be used for certificate signing purposes.
period of changing the CA’s private key must not be longer than the CA Key
lifetime minus the maximum life time of an end entity certificate.
The older , but
still valid certificate , must be available to verify old
The repository must be run at least on a best-effort basis, with an intended availability of 24x7.
must accept being audited by other
trusted CAs to
verify its compliance with the rules and procedures specified in its CP/CPS
The CA should perform operational audits of the CA/RA staff at least once per year. A list of CA and RA personnel should be maintained and verified at least once per year.
In order for an RA to validate the identity of a
person, the subject should contact the RA face-to-face and present photo-id
In case of host or service certificate requests, the CSR be delivered to the RA by the person in charge of the specific entities using a secure method.
Any single subject distinguished name must be linked to one and only one entity. Over the entire lifetime of the CA it must not be linked to any other entity.
It is not contrary to the above requirement for a single entity to have more than one associated subject name, e.g., for different key usages.
The RAs must record and archive all requests and confirmations.
The RA must communicate with the CA with secure methods that are clearly defined in the CP/CPS. (e.g. Signed emails, voice conversations with a known person, SSL protected private web pages)
The EE keys must be at least 1024 bits long and must not be generated by the CA or the RA. The EE certificates must have a maximum lifetime of 1 year plus 1 month and must not be shared among end entities.
It’s upon the user to protect his private key with a pass phrase at least 12 characters long.
The end-entity certificates must be in X.509v3 format and compliant with RFC3280 unless explicitly stated otherwise. In the certificate extensions:
- a Policy Identifier must be included and must contain an OID and an OID only
- CRLDistributionPoints must be included and contain at least one http URL
- keyUsage must be included and marked as critical
- basicConstraints should be included, and when included it must be set to ‘CA: false’ and marked as critical
- if an OCSP responder, operated as a production service by the issuing CA, is available, AuthorityInfoAccess must be included and contain at least one URI
- for certificates bound to network entities, a FQDN shall be included as a dnsName in the SubjectAlternativeName
The message digests of the certificates and CRLs must be generated by a trustworthy mechanism, like SHA1 (in particular, MD5 must not be used).