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Authentication Methods Overview

Authentication Methods Overview

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KALPESH MOHANTA
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Table of contents

Password Authentication

  • Users authenticate with a username and password.

  • Simple to implement but less secure if passwords are weak or intercepted.

Certificate-based Authentication

  • Utilizes digital certificates signed by a trusted Certificate Authority (CA).

  • Scalable and manageable in large environments, offers higher security assurance.

  • Example: PEM file(private key).

  • Process:

    • Download the PEM file when creating the EC2 instance.

    • Connect to the remote server using:

        ssh -i <path of .pem file to access> <username of AMI>@<ip address of remote server>

  • scp (Secure Copy Protocol):

      scp -i <path of .pem file to access> <path of file you are transferring from your local machine> <username of AMI>@<ip address of remote server>:<directory on the remote server where the file will be copied>

Public Key Authentication

  • Uses asymmetric cryptography with a key pair: public (server-side) and private (client-side) keys.

  • More secure than passwords, especially with strong key management.

  • SSH-KEYGEN:
    - Public Key: This can be freely shared with others. It's used to encrypt data that can only be decrypted by the corresponding private key.

    - Private Key: This should be kept secret. It's used to decrypt data encrypted with the public key and proves your identity for SSH logins.

  • Process:

    • Client:

      • Generate SSH keys using

          ssh-keygen

      • Navigate to the .ssh directory and copy the public key (e.g., id_rsa.pub).

    • Remote Server:

      • Generate SSH keys using

          ssh-keygen

      • Navigate to the .ssh directory.

      • Paste the client's public key into the authorized_keys file.

    • Final Step in Client:

      •       ssh <private ip of remote server if within VPC, otherwise public ip of remote server>

Keyboard-Interactive Authentication

  • The server customizes prompts to challenge the client.

  • Often used for multi-factor authentication with OTPs or biometric data.

Biometric Authentication

  • Uses biological traits like fingerprints or facial recognition for verification.

  • Provides strong security but requires specialized hardware and software.

Token-based Authentication

  • Uses physical tokens (e.g., smart cards or USB tokens) with digital certificates or OTPs.

  • Ensures strong authentication and protects against unauthorized access.

Feel free to share and spread the knowledge! 🌟😊 Enjoy Learning! 😊

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