RSA
also: RSA encryption, RSA algorithm, Rivest-Shamir-Adleman
RSA is a widely-used asymmetric cryptographic algorithm that uses a pair of public and private keys for secure data encryption and digital signatures. It forms the basis of many Linux security tools including SSH key authentication and SSL/TLS certificates.
RSA (Rivest-Shamir-Adleman) is a public-key cryptography algorithm where two mathematically linked keys are generated: a public key that can be shared openly and a private key that must be kept secret. Data encrypted with one key can only be decrypted with the other, enabling secure communication without prior key exchange.
In Linux, RSA is most commonly used for SSH key authentication, where your private key authenticates you to remote servers without transmitting passwords. It's also fundamental to SSL/TLS certificates that secure web traffic and email encryption.
Example: You generate an RSA key pair with ssh-keygen, place your public key on a server, and use your private key to log in securely. Only your private key can decrypt the server's challenge, proving your identity.
RSA key sizes typically range from 2048 to 4096 bits; larger keys are more secure but slower. Modern systems often complement RSA with elliptic curve cryptography (ECDSA) for improved performance.