Ed25519
also: EdDSA, Curve25519
Ed25519 is a modern public-key cryptographic signature algorithm based on elliptic curve cryptography, widely used in Linux for SSH keys and secure communications.
Ed25519 is an implementation of the EdDSA (Edwards-curve Digital Signature Algorithm) using the Curve25519 elliptic curve. It provides fast, secure digital signatures with excellent performance characteristics and smaller key sizes than traditional RSA.
In Linux, Ed25519 is most commonly used for SSH authentication. You can generate an Ed25519 key pair with: ssh-keygen -t ed25519. The resulting keys are much shorter (68 characters) compared to RSA-4096 keys (1704 characters) while offering equivalent or superior security.
Ed25519 offers several advantages: it resists timing attacks, has simpler mathematical properties reducing implementation errors, and provides excellent performance. Modern Linux distributions and SSH clients strongly recommend Ed25519 over RSA for new key generation.