Q: Is Ed25519 secure enough for production use?
Yes. Ed25519 provides a 128-bit security level and is widely adopted in production systems including OpenSSH, GnuPG, Signal Protocol, and many blockchain platforms. It is considered one of the most secure and efficient digital signature algorithms available today.
Q: Are my private keys safe when using this tool?
Yes. All key generation, signing, and verification happen entirely in your browser using the Web Crypto API. No keys, messages, or signatures are ever transmitted to any server. However, you should still handle private keys with care and never share them publicly.
Q: What is the difference between Ed25519 and ECDSA?
Both are elliptic curve signature algorithms, but Ed25519 uses the twisted Edwards curve (Curve25519) while ECDSA typically uses curves like P-256. Ed25519 offers deterministic signing (no random nonce needed), faster performance, and resistance to common implementation bugs that can compromise ECDSA.
Q: What are the key and signature sizes?
Ed25519 private keys are 32 bytes (64 hex characters), public keys are 32 bytes (64 hex characters), and signatures are 64 bytes (128 hex characters). This compact size is one of Ed25519's advantages over RSA, which typically requires 2048-4096 bit keys.
Q: Can I use Ed25519 keys generated here for SSH?
The raw Ed25519 key pairs generated here are cryptographically valid, but SSH uses a specific key format (OpenSSH or PEM). You would need to convert the raw keys to the appropriate format. For SSH key generation, it is recommended to use the ssh-keygen -t ed25519 command.
Q: Why is Ed25519 signing deterministic?
Ed25519 derives the nonce from the message and private key using a hash function, rather than using a random number generator. This eliminates the risk of nonce reuse — a vulnerability that famously compromised Sony's PlayStation 3 ECDSA implementation and leaked private keys.