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The Uniqueness of Unique Identifiers (RFC1439)

IP.com Disclosure Number: IPCOM000002267D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 10 page(s) / 19K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

C. Finseth: AUTHOR

Abstract

This RFC provides information that may be useful when selecting a method to use for assigning unique identifiers to people.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 16% of the total text.

Network Working Group C. Finseth

Request for Comments: 1439 University of Minnesota

March 1993

The Uniqueness of Unique Identifiers

Status of this Memo

This memo provides information for the Internet community. It does

not specify an Internet standard. Distribution of this memo is

unlimited.

Abstract

This RFC provides information that may be useful when selecting a

method to use for assigning unique identifiers to people.

1. The Issue

Computer systems require a way to identify the people associated with

them. These identifiers have been called "user names" or "account

names." The identifers are typically short, alphanumeric strings.

In general, these identifiers must be unique.

The uniqueness is usually achieved in one of three ways:

1) The identifiers are assigned in a unique manner without using

information associated with the individual. Example identifiers are:

ax54tv

cs00034

This method was often used by large timesharing systems. While it

achieved the uniqueness property, there was no way of guessing the

identifier without knowing it through other means.

2) The identifiers are assigned in a unique manner where the bulk of

the identifier is algorithmically derived from the individual's name.

Example identifers are:

Craig.A.Finseth-1

Finseth1

caf-1

fins0001

3) The identifiers are in general not assigned in a unique manner:

the identifier is algorithmically derived from the individual's name

and duplicates are handled in an ad-hoc manner. Example identifiers

are:

Craig.Finseth

caf

Now that we have widespread electronic mail, an important feature of

an identifier system is the ability to predict the identifier based

on other information associated with the individual. This other

information is typically the person's name.

Methods two and three make such predictions possible, especially if

you have one example mapping from a person's name to the identifier.

Method two relies on using some or all of the name and

algorithmically varying it to ensure uniqueness (for example, by

appending an integer). Method three relies on using some or all of

the name and selects an alternate identifier in the case of a

duplication.

For both methods, it is important to minimize the need for making the

adjustments required to ensure uniqueness (i.e., an integer that is

not 1 or an alternate identifier). The probability that an

adjustment will be required depends on the format of the identifer

and the size of the organization.

2. Identifier Formats

There are a number of popular identifier formats. This section will

list some of them and supply both typical and maximum values for the

number of possible identifiers. A "typical" value is the number that

you are li...