Project Description
Readable or pronouncable password generator based similar to the one in OpenVMS and Multics. Uses trigraphs to create letter sequences


A simple way to generate passwords that are more secure than dictionary words and at the same time readable. A similar method is used in OpenVMS via SET PASSWORD/GENERATE (which is where I first encountered this technique), which appears to be based on Gasser's work 1


To create a new password:

    newPassword = ReadablePasswordGenerator.Creator.Generate(12);

To create a new passphrase:

      newPassword = ReadablePasswordGenerator.Creator.GeneratePhrase(12);

Sample Words
  • ndeseppichro
  • sionyhembrad
  • bactompleydr

Sample Pass Phrases
  • itu maco posio
  • beti hap nquity
  • angi pti rackfo
  • cort anoed genead


Random Password Generator, see

This password generator gives you a list of "pronounceable" passwords. It is modeled after Morrie Gasser's original generator described in

1 Gasser, M., A Random Word Generator for Pronouncable Passwords, MTR-3006,
The MITRE Corporation, Bedford, MA 01730, ESD-TR-75-97, HQ Electronic Systems Division, Hanscom AFB, MA 01731. NTIS AD A 017676.

Except that Morrie's used a second-order approximation to English and this generator uses a third-order approximation.

A descendant of Gasser's generator was added to the Multics operating system by Project Guardian in the mid 70s, and I believe Digital's VMS added a similar feature in the 80s.

FIPS Standard 181 describes a similar digraph-based generator, derived from Gasser's.

The first digraph-based password generator I know of was written by Daniel J. Edwards about 1965 for MIT's CTSS timesharing system.

Last edited May 11, 2013 at 9:38 AM by RichardHarrison, version 4