# Object Identifier (OID)

OID’s are an identification mechanism used to identify objects in a unique, persistent and universal way. Usually an OID would refer to a class of information rather than an instance of the information, e.g. an OID would refer to the standard of a file format rather than a unique instance of the file.

The OID structure is a tree based structure, similar to the DNS structure, which allows for the idenitfication of objects in a local and international context. Each node is associated with a word, starting with a lowercase and a numeric representation. Stated differently an OID is an ordered list of object identifier components (or arcs).

The formal definition of OIDs is captured in ITU-T recommendation X.208 (ASN.1) [Ed. Note: ISO/IEC 8824:1994], Chapter 28 which can be obtained from the available from the ITU. The assignment of the roots of the tree is provided in Appendixes B, C and D.

Example
{ iso(1) }
{ joint-iso-ccitt(2) }
{ joint-iso-ccitt(2) ds(5) algorithm(8) rsa(1)}
{ iso(1) org(3) dod(6) internet(1) private(4) enterprise(1) }


The OID tree is managed in a decentralized manner, by way of a node delegating full authority to it’s children. The organisatrion that has authority over a node is often referred to as the assigning authority.

OID that have been delegated to authorities under the IANA Private Enterprises arc are often referred to as PEN (Private Enterprise Numbers). The range of PEN numbers is 0 to 2^32-1. The original definition for PEN numbers had no upper bound, however some IETF protocols do limit the size of the values.

Per RFC5612 the PEN number 32473 is to be used for documentation purposes.

It should be noted that there is no cryptographic binding between the PEN registrant in the PEB registry and the PEN(s) assigned to them, i.e. there is no way to validate the ownership of a PEN.

To request a Private Enterprise Number for your organization, visit the IANA online application form here. Always confirm whether your origanisation has not already been delegated authority to an arc, before submitting an application.

## Assigned Resource(s)

As per RFC2578, the following OID arc(s) has been delegated to my authority for management:

  { iso(1) org(3) dod(6) internet(1) private(4) enterprise(1) andrew-broekman(51107) }


# Resources

OID Repository Operated by Orange