Authentication Types

This guide provides an overview of the various SSH authentication types that you can use for penetration testing and understanding the security of your network.
Learn about the different SSH authentication types used in SSH Penetration Testing.
Learn which authentication types are most secure and how to correctly implement them for optimal security.
Use this guide to understand the various protocols available and identify which is best for your security requirements.

Password Authentication

  • Description: Users enter a password to authenticate themselves. This is the most basic form of SSH authentication.
  • Security: Passwords are susceptible to brute-force attacks and should be strong and regularly updated. Password authentication is generally considered less secure compared to other methods.

Public Key Authentication:

  • Description: Users generate a pair of cryptographic keys, typically an RSA or ECDSA key pair. The public key is placed on the SSH server, and the private key is kept securely on the client.
  • Security: Public key authentication is highly secure because it's based on asymmetric encryption. Even if an attacker gains access to the server, they won't have the private key.

Keyboard-Interactive Authentication

  • Description: This method prompts users for additional information, such as a one-time code from a token or a second password, after they enter their username.
  • Security: It provides an extra layer of security beyond just passwords, making it more resilient to certain attacks.

Certificate-Based Authentication

  • Description: This is similar to public key authentication, but it uses digital certificates to verify user identities. Certificates are issued by a certificate authority (CA).
  • Security: Certificate-based authentication is suitable for large-scale deployments and provides a structured way to manage user identities and keys.

Host-Based Authentication

  • Description: In host-based authentication, the client system's identity is verified based on the client host's name and the user's identity on that host.
  • Security: This method can be less secure as it relies on the security of the client host.

Two-Factor Authentication (2FA)

  • Description: This combines two authentication methods, typically something the user knows (password) and something the user has (a token, smartphone app, or hardware token).
  • Security: 2FA significantly enhances security, making it harder for unauthorized users to gain access.

Biometric Authentication

  • Description: Some SSH implementations support biometric authentication, where a user's fingerprint or other biometric data is used to verify their identity.
  • Security: Biometrics can provide strong authentication, but their security depends on the implementation and the accuracy of the biometric system.

GSSAPI Authentication (Kerberos)

  • Description: GSSAPI (Generic Security Service Application Program Interface) is used for integrating SSH with Kerberos authentication systems.
  • Security: Kerberos provides a strong authentication framework for securing SSH connections.