If you’re planning to take the SY0-401 version or the SY0-501 version of the Security+ exam, you should have a basic understanding of how systems and users provide credentials to verify their identity. This includes using biometrics for authentication.
For example, can you answer this question?
Q. Users at your organization currently use a combination of smart cards and passwords, but an updated security policy requires multifactor security using three different factors. Which of the following can you add to meet the new requirement?
A. Four-digit PIN
B. Hardware tokens
C. Fingerprint readers
D. USB tokens
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 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. This post covers the three factors:
- 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
Something You Are
The something you are authentication factor uses biometrics for authentication. Biometric methods are the strongest form of authentication because they are the most difficult for an attacker to falsify. In comparison, passwords are the weakest form of authentication.
Biometric Errors
Biometrics can be very exact when the technology is implemented accurately. However, it is possible for a biometric manufacturer to take shortcuts and not implement it correctly, resulting in false readings. Two biometric false readings are:
- False acceptance. This is when a biometric system incorrectly identifies an unauthorized user as an authorized user. The False Accept Rate (FAR, also known as a type 2 error) identifies the percentage of times false acceptance occurs.
- False rejection. This is when a biometric system incorrectly rejects an authorized user. The False Reject Rate (FRR, also known as a type 1 error) identifies the percentage of times false rejections occur.
True readings occur when the biometric system accurately accepts or rejects a user. For example, true acceptance is when the biometric system accurately determines a positive match. In contrast, true rejection occurs when the biometric system accurately determines a nonmatch.
As an example, a local grocery store had problems with false acceptance. It allowed shoppers to register their debit cards with their fingerprints. Once the shoppers registered their debit cards, they could simply place one of their fingers in a fingerprint reader instead of swiping a debit card and entering a PIN. Then one day, all the fingerprint scanners disappeared. Store management had discovered that the scanners were falsely accepting some users. Users who had not registered their debit cards tried the fingerprint scanners to pay for groceries, and it worked. Instead of rejecting these unknown users, the system falsely accepted them as a known user and charged their grocery purchase to someone else’s bank account.
Amusement parks often have problems with false rejection later in the season. Families are often the biggest customers of these annual passes. Children grow enough during the season that the handprint recorded for them early in the season no longer matches for them later in the season.
Somewhere You Are
The somewhere you are authentication factor identifies a user’s location. Geolocation is a group of technologies used to identify a user’s location and is the most common method used in this factor. Many authentication systems use the Internet Protocol (IP) address for geolocation. The IP address provides information on the country, region, state, city, and sometimes even the zip code.
As an example, I once hired a virtual assistant in India to do some data entry for me. I created an account for the assistant in an online application called Hootsuite and sent him the logon information. However, when he attempted to log on, Hootsuite recognized that his IP was in India but I always logged on from an IP in the United States. Hootsuite blocked his access and then sent me an email saying that someone from India was trying to log on. They also provided me directions on how to grant him access if he was a legitimate user, but it was comforting to know they detected and blocked this access automatically.
Within an organization, it’s possible to use the computer name or the MAC address of a system for the somewhere you are factor. For example, in a Microsoft Active Directory domain, you can configure accounts so that users can only log on to the network through one specific computer. If they aren’t at that computer, the system blocks them from logging on at all.
Something You Do
The something you do authentication factor refers to actions you can take such as gestures on a touch screen. As an example, Microsoft Windows 8 supports picture passwords. Users first select a picture, and then they can add three gestures as their picture password. Gestures include tapping in specific places on the picture, drawing lines between items with a finger, or drawing a circle around an item such as someone’s head. After registering the picture and their gestures, users repeat these gestures to log on again later.
Other examples of something you do include how you write or how you type. For example, keystroke dynamics measures the pattern and rhythm as a user types on a keyboard. It measures details such as speed, dwell time, and flight time. Dwell time is the time a key is pressed, and flight time is the time between releasing one key and pressing the next key. Many security professionals refer to this as behavioral biometrics because it identifies behavioral traits of an individual. However, some people put these actions into the something you do authentication factor.
Q. Users at your organization currently use a combination of smart cards and passwords, but an updated security policy requires multifactor security using three different factors. Which of the following can you add to meet the new requirement?
A. Four-digit PIN
B. Hardware tokens
C. Fingerprint readers
D. USB tokens
Answer is C. Fingerprint readers would add biometrics from the something you are factor of authentication as a third factor of authentication. The current system includes methods in the something you have factor (smart cards) and in the something you know factor (passwords), so any solution requires a method that isn’t using one of these two factors.
A PIN is in the something you know factor.
Hardware tokens and USB tokens are in the something you have factor.
If you’re studying for the SY0-501 version of the exam, check out the CompTIA Security+ Get Certified Get Ahead: SY0-501 Study Guide.