Establishing the right authentication protocol for your business is one way to achieve better security, but the process can be overwhelming.
We’ll walk you through some common authentication protocols and how they work.
An authentication protocol enables a receiving entity (such as a server) to verify the user identity of another party. User authentication protocols secure communication between computer networks.
NTLM (Windows NT LAN Manager) is a suite of protocols used to authenticate a client to a resource in an Active Directory domain. This suite includes NTLMv1, NTLMv2, and NTLM2 Session protocols.
NTLM was the primary method of authentication prior to Windows 2000 and is vulnerable to many different attacks like pass-the-hash and brute force. However, many still widely deployed to maintain compatibility with older systems that cannot use newer cryptography.
NTLM uses a challenge-response method of authentication. This is where the domain controller or target computer checks the stored hash of the client to make sure it is a match. When there is a match, it allows the client access to the resource. The system stores NTLM passwords either in the SAM database of the registry (when local authentication is happening) or on the domain controller in the ntds.dit file.
Microsoft replaced NTLM with Kerberos as the preferred method of authentication starting with Windows 2000. Kerberos has implementations across other operating systems and is maintained by The Kerberos Consortium as an open-source project. Microsoft created its own version of Kerberos and has used it as the go-to protocol for authentication across its platforms.
Kerberos adds in secret-key cryptography as well as a third-party ticket authorization to make it a more secure method of authentication. The protocol derived its name from the Greek mythology guardian of the underworld, Cerberus the three-headed dog. The three heads in Kerberos are the client, the server, and the Key Distribution Center (KDC). The KDC has the role of both the Authentication Server (AS) and The Ticket Granting Server (TGS).
Learn How To Defend Against Kerberos Attacks>
Lightweight directory access protocol (LDAP) is a protocol that makes it possible for applications to query user information rapidly. LDAP has been in use since the early 90s and has been a significant part of many networks since.
You can use it to not solely authentication. You can also use it to find files and devices on a network, or modify entries in the database. Most environments do not use LDAP for pure authentication, as it is not as secure by default, and easy to misconfigure. For example, LDAP on its own (without configuring LDAPS) sends authentication in plaintext over the network.
LDAP without the use of TLS/SSL is fairly simple. The client requests information from the LDAP server over port 389. This is called a “bind request” and includes the account name, domain name, as well as the user password. The system checks the password against the bind database, and returns the access or information.
Remote Authentication Dial In User Service (RADIUS) is a client-server network protocol. It was originally designed to authenticate remote users to a dial-in access server and with low-bandwidth conditions in mind.
RADIUS authentication begins when the client requests access to a resource through the Remote Access Server (RAS) or Network Access Server (NAS). The RAS passes along the authentication request to the RADIUS server. It then checks the information against a locally stored database file or other external source such as Active Directory.
Protocol |
Authentication |
Encryption |
Some Common Attacks |
NTLMv1 |
Challenge-response |
DES |
Authentication downgrade |
NTLMv2 |
Challenge-response |
HMAC-MD5 |
Pass-The-Hash |
Kerberos |
Third-party ticket |
DES_CBC_CRC DES_CBC_MD5 RC4_HMAC_MD5 AES128_HMAC_SHA1 AES256_HMAC_SHA1 |
Pass-the-ticket |
LDAP |
Makes use of Kerberos, RADIUS, or OAuth |
None |
Account Discovery |
Radius |
Centralized |
Many, but most common are: EAP-TLS PEAP-MSCHAPv2 EAP-TTLS/PAP |
Response Authenticator |
The right protocol for your environment depends on your existing infrastructure and application needs. All types of authentication methods are susceptible to cyberattacks and come with pros and cons. When considering protocols, ask yourself the following questions:
To determine what authentication protocol is used, check the network configuration settings on the device or service that you use to authenticate. Here are some steps you can follow:
By following these steps, you can determine what authentication protocol is being used and ensure that the appropriate security measures are in place.
There are several insecure authentication protocols that are no longer recommended for use. This is due to their weaknesses and susceptibility to attacks. Here are some examples:
Overall, it is recommended to avoid using insecure authentication protocols and use stronger authentication mechanisms that provide encryption and protection against attacks.
Finding the right authentication method is one way to get started with your organization’s cybersecurity maturity journey, but it’s just the tip of the iceberg. Having complete visibility across your environment is the ultimate goal.
As a cloud-based SIEM+XDR platform, Blumira does things differently by providing more value for better security outcomes, including:
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