Create an anonymous ID

Create an anonymous ID based on a personal ID number and a combination of the Initials and the year of birth (Initials+YoB). An exhaustive search can find the original values matching the anonymous ID unless a strong Key is added for security. Therefore, make sure the personal ID number cannot easily be used to identify a person (more information).

All fields   ID Length
Initials+YoB  Personal ID  Anonymous ID 
Key (increases security)

You may paste a list of Initials+YoB/Personal ID pairs on separate lines in the text field. Initials+YoB and ID fields must be separated by spaces, tabs, commas, or semicolons. Only the first two fields are used, unless the All fields box is checked. With the All fields box checked, all text on a row is used to generate an ID. A "-" dash is inserted as a separator. A tab-delimited list of Initials+YoB, Personal ID, and Anonymous ID will be returned. Formats for Initials+YoB and Personal ID fields are not fixed. You can use any number and type of printable characters, except that you cannot use one of ", ;" (comma nor semicolon) nor white-space characters (space, tab, newline). Note that the fields are case sensitive "june", "June", and "JUNE" all give different Anonymous IDs.

The minumum length chosen for the anonymous ID should be at least 1 1/3 times the number of digits of the maximal number of person IDs ever needed (order of magnitude). For example, if upto around 100,000 persons would ever need an anonymous ID, a length of 8 would suffice (1.33*6). More precisely, there will be a % chance of two or more persons getting the same ID ("collision") after giving out 238 thousand ID numbers, for a chosen ID length of 8 characters (more information).

Note: These numbers are approximations. See NO-WARRANTY clause below.

Create an anonymous ID
Anonymous IDs are created by client side (in-page) JavaScript. This page can be saved locally and used from local storage. No information should be transmitted from your computer.
Copyright © 2011 R.J.J.H. van Son
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JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined in FIPS 180-1
Copyright © 2000 - 2009 Paul Johnston, Version 2.2
Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
Distributed under the BSD License
See for details.