
What is authentication? and its 3 types, an ultimate guide.
Introduction
Authentication in Identity and Access Management (IAM) is a fundamental process that verifies the identity of users attempting to access systems and resources. It serves as the first line of defense against unauthorized access by ensuring that only legitimate users can enter a system. This process typically involves the presentation of credentials, such as passwords, biometrics, or security tokens, which are then validated against a database. Effective authentication mechanisms are critical for maintaining security and protecting sensitive data, as they prevent unauthorized users from gaining access and potentially causing harm. In modern IAM systems, authentication methods are continually evolving to address emerging security challenges and enhance user experience.
The problem with passwords
Passwords have been the main way to secure digital accounts for a long time. A static password is a secret word or phrase that a user types in to access a protected resource. However, passwords have many problems.
Short passwords can be easily guessed by attackers trying every possible combination. Long passwords are harder to guess but difficult to remember, often leading people to write them down, which risks them being stolen. If someone steals a password, they can pretend to be the account owner and do unauthorized things.
Single sign-on (SSO) systems, where one password gives access to many accounts, make this problem worse. If an SSO password is stolen, it can lead to unauthorized access to many systems. These issues show why we need better ways to secure accounts beyond just using passwords.
Stronger Forms of Authentication
To avoid the weaknesses of static passwords, there are stronger forms of authentication. One widely used method is the one-time password (OTP), which is often sent to users via SMS or email. OTPs are numeric codes that are valid for a short period and can only be used once, making them more secure against theft.
Another strong authentication method involves using devices like smartcards or hardware tokens. These devices generate or store cryptographic keys, providing an additional layer of security. Users must enter a PIN or provide a biometric factor, such as a fingerprint, to unlock these devices, adding further protection.
Biometric authentication, such as fingerprints, facial scans, and voice recognition, is another strong method. These techniques are harder to fake and provide a unique identifier for each user. Popular examples include Apple’s Face ID and Touch ID, and the Android framework also supports biometric authentication.
Knowledge-based authentication (KBA), which involves answering security questions, is less reliable as answers can be guessed or obtained through public information.
Overall, these stronger forms of authentication enhance security by adding multiple layers of verification, reducing the risk of unauthorized access.
Stronger Forms of Authentication
To avoid the weaknesses of static passwords, there are several stronger forms of authentication:
- One-Time Passwords (OTP):
- Description: OTPs are numeric codes sent to users via SMS or email.
- Security: They are valid for a short period and can only be used once, making them more secure against theft.
- Devices with Cryptographic Keys:
- Description: These include smartcards or hardware tokens that generate or store cryptographic keys.
- Usage: Users must enter a PIN or provide a biometric factor (e.g., fingerprint) to unlock these devices.
- Security: They provide an additional layer of security by requiring something the user has (the device) and something they know (the PIN or biometric factor).
- Biometric Authentication:
- Description: This includes fingerprints, facial scans, and voice recognition.
- Examples: Popular implementations include Apple’s Face ID and Touch ID, and the Android framework supports biometric authentication.
- Security: Biometric factors are unique to each individual and are harder to fake, providing strong identification.
- Knowledge-Based Authentication (KBA):
- Description: This involves answering security questions.
- Security: KBA is less reliable because answers can often be guessed or obtained through public information.
Overall, these stronger forms of authentication enhance security by adding multiple layers of verification, significantly reducing the risk of unauthorized access.
Multi-Factor Authentication

Multi-factor authentication (MFA) enhances security by requiring multiple methods to verify a user’s identity. Typically, it involves something you know (like a password), something you have (like a mobile phone or hardware token), and something you are (like a fingerprint or facial scan). By combining these factors, MFA significantly reduces the risk of unauthorized access.
Sure, here are the three types of authentication used in multi-factor authentication, organized in bullet points:
- Something you know: This involves using information that only the user knows.
- Password
- Passphrase
- Something you have: This involves using a physical object that the user possesses.
- Mobile phone
- Hardware token
- Something you are: This involves using a biological characteristic of the user.
- Fingerprint
- Facial scan
For example, even if a hacker steals your password, they would also need your mobile phone to generate a one-time password (OTP) to gain access. This added layer of security ensures that access is granted only to the rightful owner.
MFA is often required in environments where sensitive data is accessed, such as administrative access to cloud servers. It might be enforced continuously or only in specific situations, such as accessing from a new device or location.
When selecting authentication methods, it’s crucial to consider the sensitivity of the application and data, as well as the usability for the end-users. Overly complex mechanisms might be circumvented or considered excessive for certain situations.
By implementing MFA, organizations provide a stronger assurance that access to resources is secured, even if one factor is compromised.
Set-Up Authentication and Authentication Levels
Step-up authentication enhances security by requiring stronger forms of verification for more sensitive actions. When a user authenticates, the system evaluates the level of assurance needed. For example, logging in with a password might be considered “level one” assurance, suitable for low-risk activities. If a higher level of security is needed, such as when accessing sensitive data, the user may need to provide additional verification, like a one-time password (OTP) sent to their phone.
Here’s a breakdown of the key points:
- Authentication Levels:
- Level One: Basic authentication, such as a password, suitable for low-risk activities.
- Higher Levels: Enhanced verification, such as OTP, required for accessing sensitive data.
- Step-Up Authentication:
- Increases the level of verification during a session if a higher level of security is needed.
- Ensures that more sensitive actions require stronger authentication.
For instance, a user might browse a retail website anonymously but need to enter a password to access their stored address information. To approve a large payment, they might then need to provide an OTP. This model ensures that the strength of the authentication mechanism matches the sensitivity of the action being performed, providing robust security for critical transactions and data access.
Multi-Factor Authentication and SSO
The use of multi-factor authentication (MFA) can affect the user experience when combined with single sign-on (SSO). SSO allows users to log in once and access multiple applications, but different applications may require different levels of authentication strength.
For example, a user might log in with a password to access a basic application but then need to provide a one-time password (OTP) sent to their phone for more sensitive applications. This ensures higher security but may require users to authenticate again, impacting the “login once, access everything” promise of SSO.
When implementing SSO with MFA, it’s essential to:
- Avoid promises like “login once, access everything” if different authentication levels are needed.
- Inform users in advance if stronger authentication will be required for certain actions to reduce confusion.
- Ensure that notifications about additional authentication steps are clear but not intrusive to avoid user frustration.
By carefully planning and communicating the requirements, organizations can enhance security while maintaining a positive user experience.
Session Timeouts
Session timeouts are crucial for maintaining security in identity and access management. They determine how long a session can remain active before requiring re-authentication. Shorter session timeouts are particularly important for sessions with elevated privileges, as they reduce the risk of unauthorized access if a session is hijacked.
Key points to consider:
- Shorter Session Timeouts:
- Important for sessions with elevated access to sensitive resources.
- Reduce the risk of sessions being hijacked for malicious purposes.
- Authentication Assurance Levels:
- Higher assurance levels might require shorter session durations to maintain security.
- Align with the principle of least privilege, ensuring that access is only granted for the necessary duration.
By configuring appropriate session timeouts, organizations can enhance the security of their systems, particularly for high-risk or privileged activities.
SAML 2 and OIDC
SAML 2
SAML 2.0 (Security Assertion Markup Language) is a protocol used to authenticate users between an identity provider and a service provider. It allows for secure and seamless single sign-on (SSO) experiences. Here’s how it works:
- Authentication Request:
- A SAML 2.0 authentication request specifies the desired authentication context using the
<RequestedAuthnContext>
element. - This element indicates the authentication class required for the user.
- A SAML 2.0 authentication request specifies the desired authentication context using the
- Response:
- The identity provider authenticates the user according to the specified context.
- The response will include the authentication context class used in the
<AuthnContext>
element of the authentication assertion.
OIDC
OIDC clients can request one or more authentication context classes in order of preference, using the acr_values
parameter in the authentication request. These context classes indicate the level and method of authentication required.
- acr_values: Authentication context class reference.
An ID Token issued to an application can contain the following parameters to convey the authentication context and methods used:
- acr: Authentication context class reference, an identifier for the authentication context class.
- amr: Authentication method reference, identifiers for one or more methods used to authenticate a user.
Step-Down Authentication
Step-down authentication aligns with the principle of “least privilege,” ensuring users operate with only the necessary access levels. In environments with varying levels of sensitive resources, users might start a session with higher privileges but should step down to lower levels when those privileges are no longer needed. This process helps mitigate risks by limiting the duration that elevated privileges are in use.
Key points include:
- Access Levels:
- Users may start with higher access levels to perform sensitive tasks.
- Once the tasks are completed, the session should step down to a lower access level.
- Mitigating Risks:
- Reduces potential damage from compromised sessions.
- Minimizes the impact of human error when operating at higher privilege levels.
- Implementation:
- Step-down can be managed through explicit mechanisms or by relying on shorter session timeouts.
- Ensures that high-privilege sessions do not remain active longer than necessary.
Step-down authentication is practical for maintaining security by dynamically adjusting access levels based on the current needs and activities of the user.
Summary
In summary, effective identity and access management (IAM) is crucial for securing digital resources. Authentication, the first line of defense, evolves from static passwords to stronger methods like one-time passwords, biometrics, and multi-factor authentication (MFA). MFA combines something you know, have, and are, enhancing security significantly. Single sign-on (SSO) integrates with MFA to balance security and user experience. Step-up and step-down authentication adjust security levels based on the sensitivity of actions, ensuring least privilege principles are maintained. Proper session timeout management further fortifies security, especially for high-privilege tasks. By leveraging these strategies, organizations can robustly protect their systems and data.
“I think of passwords as the cockroaches of our industry. No matter how we try and stomp them and eliminate them, they keep popping up. I hate passwords because they give a false sense of security.”
Don Thibeau, Executive Director of the OpenID Foundation (Ubisecure Digital Identity Management).
References
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