Global Trust Authority - GTA Glossary

The following list explains the meaning of terms and abbreviations, frequently used within the GTA.

Term	Abbreviation	Meaning
Attribute Authority	AA	An entity trusted by one or more entities to create and assign attribute certificates. Note that a CA may also be an AA.
Attribute Certificate		A set of attributes which are bound to an entity by the signature of a trusted entity.
Authorised Relying Party	ARP	A relying party that is internal to the GTA infrastructure (i.e. it has a contractual relationship with an STA, covering certificate validation services). The ARP may or may not also hold a certificate (i.e. may or may not be a subscriber).
Authority Certificate		A certificate whose subject is a CA and whose associated private key is used to sign certificates.
Authority Revocation List	ARL	A CRL that only identifies revoked authority certificates and no end entity certificates. The GTA issues an ARL for the purpose of identifying revoked MTA certificates.
Certificate Policy	CP	A named set of rules that indicates the applicability of a certificate to a particular community and/or class of applications with common security requirements. The document, managed by a CA, describes among other things the manner in which Identity Certificates issued by the CA may be used and the obligations of the CA and the relevant End Entity in relation to such Identity Certificates. The Certificate Policy (or policies) under which a certificate is issued is indicated in the 'certificate policies' extension of the certificate.
Certificate Revocation List	CRL	A digitally signed list issued by an STA to identify end entity certificates that have been revoked but have not expired yet.
Certificate Validation		The process of checking the revocation status of the certificate of a requesting party, either by comparing the certificate with its possible occurrence on a CRL/ARL or by sending an OCSP request.
Certification Authority	CA	An entity trusted by one or more entities to create, assign and revoke or hold public key certificates. In the GTA infrastructure all TAs are CAs.
Certification Practice Statement	CPS	A statement of the practices which a CA employs in issuing certificates. The GTA CPS describes the practices employed by the GTA to support its certification services to MTAs. A separate CPS is provided by each MTA, which describes the procedures, and practices carried out by that MTA in issuing certificates to its STAs. Similarly, each STA has a its own CPS which describes the procedures and practices followed by that STA in issuing certificates to its end entities. To ensure a consistent level of trust, security and interoperability across the GTA hierarchy, the GTA sets minimum requirements, which all Trust Authorities (TAs) within the GTI must comply with. These are included in the GTA Rule Book.
Cross certification		A process by which two CAs mutually certify each other's public keys and a particular CP in the first domain is considered by the authority of the first domain to be equivalent to a particular CP in the first domain.
Cross validation		The situation where an Authorised Relying Party under either an external PKI or the GTA structure is able to transparently validate certificates issued to end users under the auspices of both PKIs. Conversely, an end user with and ID certificate issued under the auspices of on external PKI or the GTA can be transparently accepted by an Authorised Relying Party under both structures.
End entity (End user)		A certificate subject that uses its private key for purposes other than signing certificates or an entity that is a relying party. The term end-user has the same meaning.
External Relying Party		A relying party that does not have a contractual relationship with any STA covering services for the validation of certificates.
Global Trust Authority	GTA	An organisation which provides a global PKI framework. Global Trust Authority S.c.r.l. is a company incorporated in Belgium with its principal place of business at rue Marie Théreèse 11, 1000 Brussels.
Global Trust Authority Infrastructure	GTI	The public key infrastructure established and maintained by GTA, consisting of at least the GTA, all MTAs and All STAs.
GTA Operational Authority	GOA	A management group established by the GTA Board for authorising the operations to be performed on the GTA Root.
GTA Policy Authority	GPA	The part of the GTA organisation that sets the policy rules of how the GTI will operate. The GTA Board will act as the policy authority for the GTA.
GTA Root Processor		The external entity that provides and manages the secure operation of the GTA Root (i.e. the party that is providing the outsource service for the GTA Root).
Identity Certificate	ID cert	A digital certificate that cryptographically binds a public key to the identity of the owner of the public key.
Master Trust Authority	MTA	A Trust Authority which exists at level 2 of the GTA hierarchy. MTAs are responsible for registering and certifying STAs.
OCSP Responder		An entity that provides OCSP responses.
Online Certificate Status Protocol	OCSP	A protocol useful in determining the current status of a digital certificate, without requiring CRLs. OCSP provides more timely revocation information and may be used to obtain additional status information. An OCSP client issues a status request to an OCSP responder and suspends acceptance of the certificate in question until the responder provides a response.
Policy Approval Authority	PAA	A management group that is responsible for authorising the use of particular certificate policies and certification practice statement(s) for a PKI. The overall PAA for the GTA infrastructure is the GTA Board. Each MTA and STA has its own PAA.
Public Key Certificate		The public key and identity of an entity together with some other information, rendered unforgeable by signing the certificate information with the private key of the certifying authority that issued that public key certificate.
Public Key Infrastructure	PKI	An infrastructure (consisting of software, hardware, procedures, personnel, documentation, etc.) that governs the use of public key cryptography.
Registration Authority	RA	An entity who is responsible for identification and authentication of subjects of certificates, but is not a CA or an AA and hence does not sign or issue certificates. A RA may assist in the certificate application process, revocation process, or both.
Relying Party	RP	An entity which accepts and relies on a certificate. Within the GTI, there are two types of relying parties: Authorised Relying Parties and External Relying Parties.
Root key		The public key used to validate the first certificate in the chain of certificates as a part of certification path processing, in this case the public key of the GTA.
Rule Book		A set of documents which sets out the various rules and requirements for parties participating in the GTA Infrastructure, parts of which are to be made available by the GTA to each MTA and parts of which are to be made available by each MTA to each of its STAs.
Scheme		A system that provides application services to its users based on PKI services via one or more STAs.
Scheme Trust Authority	STA	A role offering TA services to a particular scheme. STAs are responsible for issuing certificates to end-users.
Subscriber		An entity to which a certificate is issued (also known as the certificate subject).
Trust Authority	TA	An entity that can be relied on to implement GTA Infrastructure services and to uphold GTA Infrastructure requirements for security and risk management. This primarily consists of a certification authority but may include other roles such as registration authority, key recovery agent, etc. The GTA, MTA and STA are all TAs.
Validation Authority	VA	An independent role that keeps an on-line database for the validation of STAs and MTAs. Also used to denote an OCSP Responder.

Global Trust Authority - 2001