Authentication protocols serve as the backbone of online security, allowing users to securely confirm their identity and access protected information and services. They define how claimants (the users trying to access a digital service) and verifiers (the entities that authenticate them) communicate. The protocols exchange information to verify the validity of the authentication service and confirm that the requester has the appropriate token to authenticate their identity.
With the myriad of authentication protocols available, however, selecting the appropriate one for your organization can be daunting. Below are the key authentication protocols, along with detailed information on choosing the right one for your business needs.
The authentication protocol landscape
Each authentication protocol offers unique capabilities tailored to specific use cases and security requirements. If you’re trying to figure out which one is best for your business, consider these four authentication protocols and their potential use cases.
OAuth/OpenID Connect (OIDC). OAuth, designed primarily for authorization, allows users to grant third-party applications limited access to their private resources without revealing their credentials. You might consider using OAuth from providers like Google and GitHub to prioritize quick user registrations and get validated information.
OpenID Connect (OIDC) is an open standard that builds on OAuth by providing authentication functionality using an ID token to securely verify the user’s identity. OIDC is suitable for scenarios where interoperability and user authentication across multiple systems are critical, such as in federated identity management systems.
Both OAuth and OpenID Connect are widely adopted, enabling interoperability between different systems and allowing users to authenticate once to use the same credentials across multiple services. OAuth and OpenID Connect are, however, subject to phishing attacks and token theft if not implemented securely.
SAML (Security Assertion Markup Language). SAML is an XML-based standard for exchanging identity information between the user, identity provider (IdP), and service provider (SP). SAML offloads authentication responsibilities to specialized IdPs, reducing the burden on service providers and improving security. SAML works best for single sign-on (SSO) authentication in enterprise environments, where centralized authentication and access control are essential.
SAML supports use cases like identity federation, but SAML configurations can be complex and require careful management. SAML’s reliance on XML can also introduce complexity since it is an older format than more modern ones like JSON.
FIDO2 / WebAuthn. FIDO2 is an open standard for passwordless authentication that relies on enrolled devices or hardware security keys to verify user identities. WebAuthn, a component of FIDO2, enables passwordless authentication via biometric and possession-based methods. You might consider WebAuthn for consumer-facing applications and mobile-first experiences, leveraging native device capabilities for simple, secure authentication.
Access keys, which are cross-device credentials based on WebAuthn standards, have been implemented in several large organizations such as Google, Apple, Shopify, Best Buy, TikTok, and GitHub in recent years. Success stories from early adopters and increased awareness among end users are sure to continue to drive adoption for years to come.
FIDO2 and WebAuthn they provide strong security against phishing and other attacks, since they don’t rely on shared secrets like passwords, and a user-friendly experience, since users don’t have to remember complex passwords. That said, FIDO2 and WebAuthn are not compatible with all devices and browsers; Current gaps in support may make these protocols inconvenient for some users.
Time-based one-time password (TOTP). TOTAL generates one-time passcodes based on a shared secret key and the current time, often providing an additional layer of security in multi-factor authentication (MFA) setups. TOTP supports both hardware tokens and software-based authentication applications. You should consider TOTP for various authentication scenarios that require increased security.
TOTP provides an additional layer of security beyond the password, as the code changes frequently and is tied to the specific device that generates it. TOTP, however, requires the user to have a separate device to generate codesand does not protect against phishing if the user is tricked into handing the code over to the attacker.
Factors in choosing an authentication protocol
It’s easy to generalize which of the four protocols above you should use. Business applications aimed at enterprises should use SAML for its robust SSO capabilities and centralized authentication management. Consumer and mobile applications should choose WebAuthn/passkey to provide a simple and secure authentication experience that takes advantage of native device features such as biometrics.
That said, every business has unique needs and it’s not always best to generalize. Here are some factors to keep in mind when choosing an authentication protocol:
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Security levels: Prioritize protocols that offer robust security measures to safeguard user data and prevent unauthorized access.
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Integration: Choose protocols that integrate seamlessly with your existing infrastructure to simplify deployment and maintenance processes.
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Scalability: Make sure the protocol you select can accommodate your organization’s growth and growing user base without compromising performance or security.
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Authentication method: Consider your users’ preferred authentication methods and select protocols that align with their expectations and UX preferences.
Choosing the right authentication protocol is critical to maintaining the security and trust of your users. By understanding the characteristics and use cases of different protocols and considering factors such as security, integration, scalability and user experience, you can select the protocol best suited to your organization’s needs.