Authentication and authorization are two vital information security processes that administrators use to protect systems and information. Authentication verifies the identity of a user or service, and authorization determines their access rights. Although the two terms sound alike, they play separate but equally essential roles in securing applications and data. Understanding the difference is crucial. Combined, they determine the security of a system. You cannot have a secure solution unless you have configured both authentication and authorization correctly.
What is Authentication (AuthN)?
Authentication (AuthN) is a process that verifies that
someone or something is
who they say they are. Technology systems typically use some form of
authentication to secure access to an application or its data. For example,
when you need to access an online site or service, you usually have to enter
your username and password. Then, behind the scenes, it compares the username
and password you entered with a record it has on its database. If the
information you submitted matches, the system assumes you are a valid user and
grants you access. System authentication in this example presumes that only
you
would know the correct username and password. It, therefore, authenticates you
by using the principle of something only you would know.
What is the Purpose of Authentication?
The purpose of authentication is to verify that
someone or something is who or
what they claim to be. There are many forms of authentication. For example,
the
art world has processes and institutions that confirm a painting or sculpture
is the work of a particular artist. Likewise, governments use different
authentication techniques to protect their currency from counterfeiting.
Typically, authentication protects items of value, and in the information age,
it protects systems and data.
What is Identity Authentication?
Identity authentication is the process of verifying the identity of a user or service. Based on this information, a system then provides the user with the appropriate access. For example, let's say we have two people working in a coffee shop, Lucia and Rahul. Lucia is the coffee shop manager while Rahul is the barista. The coffee shop uses a Point of Sale (POS) system where waiters and baristas can place orders for preparation. In this example, the POS would use some process to verify Lucia or Rahul's identity before allowing them access to the system. For instance, it may ask them for a username and password, or they may need to scan their thumb on a fingerprint reader. As the coffee shop needs to secure access to its POS, employees using the system need to verify their identity via an authentication process.
What is Authorization (AuthZ)?
Authorization is the security process that determines a user or service's level of access. In technology, we use authorization to give users or services permission to access some data or perform a particular action. If we revisit our coffee shop example, Rahul and Lucia have different roles in the coffee shop. As Rahul is a barista, he may only place and view orders. Lucia, on the other hand, in her role as manager, may also have access to the daily sales totals. Since Rahul and Lucia have different jobs in the coffee shop, the system would use their verified identity to provide each user with individual permissions. It is vital to note the difference here between authentication and authorization. Authentication verifies the user (Lucia) before allowing them access, and authorization determines what they can do once the system has granted them access (view sales information).
What are the Similarities Between Authorization and Authentication?
Authentication and authorization are similar in that they are two parts of the underlying process that provides access. Consequently, the two terms are often confused in information security as they share the same "auth" abbreviation. Authentication and authorization are also similar in the way they both leverage identity. For example, one verifies an identity before granting access, while the other uses this verified identity to control access.