How to Manage SSH Key Overview

What is an SSH?

SSH key is an integral part of SSH (Secure Shell) which enhances the security of the connection. By generating an SSH key you can access without a password login, and secure connection. In digital time secure communication and access to remote servers are essential. 

What is an SSH Key?

SSH key consist of public and private key pair which is used to secure access to remote servers. It supports various keys like RSA, ECDSA, DSA, and Ed25519. Each of the keys has its own length and size. When you connect to a remote server, the SSH client uses your private key.

The server verifies the SSH key. If they are match then you connect to the server without a password. The cryptographic algorithm is used to generate the SSH key making them highly secure. 

What is a Public Key?

The public key is used in modern encryption systems. It is part of cryptography which uses the key pairs. Each key pair consists of a public key and a private key. The public key is available for everyone and used to encrypt the message.

Once the message is encrypted with the public key, only the private key decrypts it. It helps to protect the data during the transmission. The public key provides the user with secure communication and, a digital signature. 

What is a Private Key?

The private key is a part of the cryptographic system used for securing data and communication. This system uses the key pairs for encryption and decryption. The private key is kept confidential while the public key can be shared widely.

The private key consists of a long, random combination of mixed letters that cannot be easily guessed. The public key can be regenerated using the private key but the public key does not generate a private key.

The private key is used to generate the digital signature. When someone sends you an encrypted message by using the public key. Only the private key decrypt and access the message. A private key prevents unauthorized access to encrypted data. Private keys provide privacy and security to data.

What is the Passphrase for SSH Key?

The passphrase for the SSH key is an extra layer of security used to encrypt and protect the private key. It is essential to enter the password while using the private key for authentication.

While generating the SSH key pairs, there is an option to set the passphrase. It is similar to the password, you have to enter this password while using the private key.

The purpose of a passphrase is to add an extra layer of security to the private key. It can prevent unauthorized access without knowing the passphrase. Hence it is important to create a strong password mix of letters (upper, lower, and special characters). Additionally, it is important to remember the password and store it in a secure location.  

Add or Change the Passphrase for SSH Key

Adding or changing a passphrase for an SSH key is setting and modifying the password that encrypts and safeguards the private key. Passphrases provide an extra security layer during the authentication process.

By adding or changing the passphrase you enhance the security of the private key. If someone else know your private key, then passphrase serves a barrier to prevent the unauthorized access.

Key Size and Algorithm for SSH Key

Key size and algorithm are the important factors that affect the security of communication.

Key size is the length of the bits. The recommended length for the key is 2048 bits and higher. Generally, the longer length of the key size provides more security. It makes the attacker guess the key. A key size less the 2048 bits is less secure and is not recommended.

Algorithm used by the SSH key is an important factor of security. They use different algorithms for authentication and encryption. The more commonly used algorithm in SSH key is RSA and ECDSA.

RSA key is a widely used algorithm that provides high-level security and performance.

ECDSA is a new algorithm that provides similar security as RSA with a smaller key size. It prevents you from the potential attacks.

Manage SSH Keys

Manage the SSH key involved to handle the key used for secure access to the server. It involves a few tasks like generating the key pair, installing the public key to the server, and securing the private key. It is essential for secure server access.

Few Additional tips for Managing SSH keys: –

Back up your SSH keys.

Create a strong passphrase for your private key.

Do not share your private key.

Rotate your SSH key.

Disable the unused SSH key.

The management of the SSH key is very efficient for the secure connection and it minimizes the risk of unauthorized access.