Password standards

Preamble

This document outlines the complexity requirements and proper management practices of passwords for all computer systems at the University of Waterloo. It is expected that all members of the University of Waterloo community abide by these standards.

Contents

Complexity requirements

  • Password history: 6
  • Minimum password length: 8
  • Password complexity requirements:
    • The password contains characters from at least three of the following five categories:
      • English uppercase characters (A — Z)
      • English lowercase characters (a — z)
      • Base 10 digits (0 — 9)
      • Non-alphanumeric (For example: !, $, #, or %)
      • Unicode characters
    • The password does not contain three or more consecutive characters from the user's account name.

See the Microsoft document on enforcing strong passwords for further explanation of the above.

The minimum password length should be 15 characters for privileged accounts.

Aging requirements

  • Maximum password age: none
  • Minimum password age: 1 day

Please note that a password age of 126 days (approximately one academic term) is strongly recommended for accounts that have access to information classified as Highly Restricted, unless the information belongs to the owner of the account. Ideally, the same practice should be followed when Restricted information is involved. See Policy 46 for the definitions of Highly Restricted and Restricted information.

For example, an account belonging to a student, to access his/her university records, does not have any password aging requirements where an account belonging to a staff/faculty member, with access to student information, should have the recommended password age.

Lockout requirements

  • Account lockout duration: 5 minutes
  • Account lockout threshold: 50 failed attempts
  • Reset account lockout counter after: 5 minutes

Breach of a password

A password is classified as Restricted in Policy 46, so a password breach is subject to the Information Security Breach Response Procedure.

Practices for end users

Choosing good passwords

A good password has the following properties:

  • It's long enough to resist automated guessing (the longer, the better).
  • It's easy to remember.

In order to satisfy these two requirements, it helps to think of passwords as passphrases instead. Good passphrases contain at least 4 unique words, include some numbers and punctuation, and be at least 15 characters in length. An example of a good passphrase:

Vision 2020, when the geese attack.

Note that while the use of dictionary words in a password is discouraged, the use of dictionary words in passphrases that are longer than 14 characters, where the passphrase meets complexity requirements, should be OK.

Shared passwords

Unless the account is a generic, shared account, a password must not be shared. Shared/Generic accounts should be used only when absolutely necessary to solve a business need. There are usually methods to solve a business need without the use of an account with a shared password.

Users with access/responsibility for other accounts, such as generic or privileged accounts, must use a unique password for each account.

Password security

A password should never be revealed to anyone, by any means. Supervisors and IT support staff who need access to an account can do so by other means.

Managing/remembering multiple passwords

Writing down your password is OK, as long as you make sure that:

  1. You don't write down anything that attributes the password to the userid or purpose of the account.
  2. You keep the password secure. (e.g., either in your wallet or under lock and key)
  3. You make an effort to remember the password so that you can destroy the paper copy.

Some people store passwords in a file on their computer. If you do this, you must ensure the file is encrypted, and that the encryption key is well protected.

Browser caching of passwords

All modern web browsers provide a facility to remember passwords to access-controlled web sites. Since there are methods of exploiting the browser cache of passwords, it is strongly recommended that the browser feature to remember passwords be disabled, especially on mobile devices.

Practices for IT Support Staff

Setting initial passwords

When setting an initial password for a user, the password should be a unique random string that's generated dynamically (e.g., by using the apg program). If the initial password is some other identifier that is not random, then a mechanism needs to be in place so that accounts are disabled if the initial password has not changed within two weeks. Any account where the initial password has not changed within six weeks should be disabled.

Use of Central Web Authentication Service

Any information system that provides web-based services to students, faculty, and/or staff, should use Waterloo's central web authentication service. This service, currently implemented with Active Directory Federation Services (ADFS), provides several benefits, including:

  • Better user experience
    • The single sign-on functionality allows a user to use multiple applications by only authenticating once.
  • Better Security
    • Fewer web sites prompting for credentials means a smaller attack surface for brute-force password cracking. This also facilitates the throttling of an attack in one place.
    • Users trained to type credentials only to the central authentication service are less susceptible to being victims of phishing.
    • Account compromises are easier to detect since the authentication always happens at the central service.
    • User passwords are harder to capture as a result of a web server compromise.

Managing passwords for service accounts

Staff responsible for service accounts should keep an inventory of these accounts. Every service account must have a unique password. A service account password must be changed as soon as reasonably practical after any staffing change involving a person who has had access to the service account password. Service account password changes should be treated like any other system change by using appropriate change control processes.

Local administrator accounts

It is common for systems administrators to create images of operating systems for deployment to multiple workstations and/or servers. Whether these hosts are in an Active Directory domain, or make use of externalized authentication such as RADIUS or LDAP, they will have a privileged local account. The management of these local accounts is often overlooked. Mechanisms should be in place so that the passwords of local privileged accounts are changed on a regular basis.

Password storage

On Unix/Linux systems, the crypt password hashing scheme must be avoided in favour of SHA-2, Blowfish, or MD5 (with salt). On Windows systems, LANMAN hashing must be disabled.

Passwords for High Security Applications

While more expensive to implement and manage, multi-factor authentication should be used in favour of static passwords for high security applications.

Password audits

All members of the University of Waterloo community should expect that any password used to access University of Waterloo computing resources be subject to regular audits. Password audits may be performed by authorized persons as follows:

  • In the case of a standalone host or service, the system administrator of that host or service.
  • Information Systems & Technology (IST) staff, under the direction of the Director, Information Security Services.
  • Audit professionals authorized by the information steward and/or the university administration.

The discovery of a weak password should be communicated to the person responsible for the associated account. What constitutes a weak password will change over time and will depend on ever-changing technology and risk.