Question:

What other authentication methods can be used for Exchange ActiveSync besides certificate-based authentication?

Answer:

This is the simplest form, where users provide a username and password. It’s easy to implement but less secure unless combined with SSL/TLS.

OAuth:

A more modern approach, OAuth allows for token-based authentication, which doesn’t require users to input their credentials directly. It’s commonly used with Office 365.

NTLM Authentication:

NTLM (NT LAN Manager) is a challenge-response authentication protocol used to authenticate a client to a resource on an Active Directory domain.

Kerberos Authentication:

A network authentication protocol designed to provide strong authentication for client/server applications by using secret-key cryptography.

Digest Authentication:

This method uses a challenge-response mechanism to confirm the user’s identity without sending the password over the network.

Two-Factor Authentication (2FA):

2FA adds an extra layer of security by requiring a second form of identification beyond just the username and password.

Modern Authentication:

This is a blanket term that refers to a combination of authentication and authorization methods, including multi-factor authentication (MFA), SAML-based federated authentication, and others.

Each of these methods has its own set of benefits and trade-offs in terms of security, convenience, and implementation complexity. Organizations should choose the method that best fits their security requirements and infrastructure capabilities. It’s also worth noting that Microsoft is continuously evolving its security features, and it’s important to stay updated with the latest options available for Exchange ActiveSync.