Secure Shell, SSH

SSH or Secure Shell, is a cryptographic network protocol that provides a secure way to access and manage network devices and servers over an unsecured network. It is widely used for secure remote administration, file transfer, and tunneling. SSH ensures that the communication between the client and the server is encrypted, making it resistant to eavesdropping and other security threats.

Common threats are:

1. Evesdropping/Passive-Attack:

Definition: Attacker or attackers can use a open source packet analyis tool to intercept and sniff your packets that might contain sensitive data.

What SSH Does: SSH will encrypt the connection between the client and the server with a cryptographic key

2. Man Middle Attack(MTM):

Definition: Attacker or Attackers will try to get into the middle of communication to eavesdrop or impersonate. Impersonating is a phishing attack that pretends to be someone. Typically changing their IP address to match the victims, creating fake accounts that "seem" to be the victim, etc.

Solution: When you use ssh, you will create two types of keys. One is a host key and the other is a public key. The public key you can distribute out to your clients or rather people that you want to connect with.This will be elaborated further down

3. Brute-Force Attack:

Definition: In simple terms, it is when a group of attackers or attacker guess a password for a username.

Solution: You can implement these methods into ssh.

4. Connection Hijacking:

Definition:Where a attack or attackers that can listen on your network traffic and inject their own traffic into yours.

Solution:SSH integrity check which is apart of the protocol can tell if the session has been changed in any way

The common keys you can use are:

1. RSA (Rivest-Shamir-Adleman):

Private Key:Typically stored in a file with a .pem or .key extension.

Public Key: Corresponding public key stored in a file with a .pub extension.

2. DSA (Digital Signature Algorithm):

Private Key: Often stored in a file with a .pem or .key extension.

Public Key: Corresponding public key stored in a file with a .pub extension.

3. ECDSA (Elliptic Curve Digital Signature Algorithm):

Private Key: Stored in a file with a .pem or .key extension.

Public Key: Corresponding public key stored in a file with a .pub extension.

4. Ed25519:

Private Key: Stored in a file with a .pem or .key extension.

Public Key: Corresponding public key stored in a file with a .pub extension.

You can click here to get started on creating your own cryptographic keys.

Key Functions of SSH:

1. Remote Login:

SSH allows users to log in to a remote server or device securely. Once connected, users can execute commands as if they were physically present at the remote machine.

2. Secure File Transfer:

SSH enables secure file transfers between systems. The most common tool for this purpose is scp (secure copy), which allows files to be transferred securely over the SSH connection.

3. Tunneling:

SSH can create secure tunnels for various network services. This is useful for encrypting traffic for protocols that may not inherently provide security.

References:

1. Installing SSH on Linux:

2. Installing SSH on Windows

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