If you’re planning to take the Security+ exam, you should have a basic understanding of authentication mechanisms. This includes implementing password security concepts and knowing the difference between identification, authentication, and authorization.
For example, can you answer this question?
Q. You are logging on to your bank’s web site using your email address and a password. What is the purpose of the email address in this example?
A. Identification
B. Authentication
C. Authorization
D. Availability
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Authentication Mechanisms
Authentication proves an identity with some type of credential, such as a username and password. For example, users claim (or profess) their identity with identifiers such as usernames or email addresses. Users then prove their identity with authentication, such as with a password.
In this context, a user’s credentials refer to both a claimed identity and an authentication mechanism. In other words, a user’s credentials can be a username and a password.
At least two entities know the credentials. One entity, such as a user, presents the credentials. The other entity is the authenticator that verifies the credentials. For example, Marge knows her username and password, and an authenticating server knows her username and password. Marge presents her credentials to the authenticating server, and the server authenticates her.
The importance of authentication cannot be understated. You can’t have any type of access control if you can’t identify a user. In other words, if everyone is anonymous, then everyone has the same access to all resources.
Also, authentication is not limited to users. Services, processes, workstations, servers, and network devices all use authentication to prove their identities. Many computers use mutual authentication, where both parties authenticate to each other.
Authentication is often simplified as types, or factors, of authentication. Entities can authenticate with any one of these factors, and administrators often combine two factors for dual-factor authentication, and two or more factors for multifactor authentication. In summary, the factors are:
- Something you know, such as a password or PIN
- Something you have, such as a smart card or USB token
- Something you are, such as a fingerprint or other biometric identification
- Somewhere you are, such as your location using geolocation technologies
- Something you do, such as gestures on a touch screen
The first factor of authentication (something you know, such as a password or PIN) is the weakest factor. The following sections are some of the important password security concepts.
Implementing Account Lockout Policies
Accounts will typically have lockout policies preventing users from guessing the password. If a user enters the wrong password too many times (such as three or five times), the system locks the user’s account. Two key phrases associated with account lockout policies are:
- Account lockout threshold. This is the maximum number of times a user can enter the wrong password. When the user exceeds the threshold, the system locks the account.
- Account lockout duration. This indicates how long an account remains locked. It could be set to 30, indicating that the system will lock the account for 30 minutes. After 30 minutes, the system automatically unlocks the account. If the duration is set to 0, the account remains locked until an administrator unlocks it.
Changing Default Passwords
Many systems and devices have default passwords. A basic security practice is to change these defaults before putting a system into use. As an example, many wireless routers have default accounts named “admin” with a default password of “admin.” If you don’t change these defaults, anyone who knows the defaults can log on and take control of the router. In that case, the attacker can even go as far as locking you out of your own network.
Changing defaults also includes changing the default name of the Administrator account, if possible. In many systems, the Administrator account can’t be locked out through regular lockout policies, so an attacker can continue to try to guess the password of the Administrator account without risking being locked out. By changing the name of the Administrator account to something else such as Not4U2Know, it reduces the chances of success for the attacker. The attacker needs to know the new administrator name before he can try to guess the password.
Some administrators go a step further and add a dummy user account named “administrator.” This account has no permissions. If someone does try to guess the password of this account, the system will lock it out, alerting administrators of possible illicit activity.
Using Previous Logon Notification
A simple technique used to alert users of possible account problems is to provide them notification of when they last logged on. You might see this as “Previous logon notification” when you first log on to a system.
As an example, consider Maggie, who took Friday off last week. She logged on last Thursday while she was at work, but she didn’t log on again all weekend. When she came in to work on Monday, she logged on and the system notified her that the last time she logged on was on Friday. If she’s paying attention to this message, she’ll realize that someone else logged on to her account. This also alerts her that her credentials have been compromised.
The primary challenge with this system is that users tend to ignore the notification. More than 99 percent of the time, the message tells users what they already know. So, instead of reading the message, users tend to ignore it.
Q. You are logging on to your bank’s web site using your email address and a password. What is the purpose of the email address in this example?
A. Identification
B. Authentication
C. Authorization
D. Availability
Answer is A. The email address provides identification for you and your account.
The password combined with the email address provides authentication, proving who you are.
Based on your identity, you are granted authorization to view your account details.
Availability is unrelated to identification, authentication, and authorization.